eni spa
exploration & production division
COMPANY SPECIFICATION
CONSTRUCTION AND INSTALLATION OF
ONSHORE PIPELINE
03516.PLI.MEC.SDS
Rev. 1 July 2012
ENGINEERING COMPANY STANDARD
This document is property of Eni S.p.A. Exploration & Production Division.
It shall neither be shown to Third Parties not used for purposes other than those for which it has been sent.
eni spa
exploration & production division
FOREWORD (REVISION HISTORY)
REV. 0
sheets 51
June 1988
First issue
REV. 1
sheets 59
July 2012
General revision
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 3 of 59
eni spa
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 4 of 59
exploration & production division
INDEX
CONSTRUCTION AND INSTALLATION OF ONSHORE PIPELINE .................................................. 1
1.
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
1.10
1.11
GENERAL......................................................................................................................... 7
PARTIES INVOLVED IN THE ENGINEERING ACTIVITIES. .......................................... 7
ACRONYMS ..................................................................................................................... 8
UNITS OF MEASUREMENT ............................................................................................ 8
INTERNATIONAL CODES AND STANDARDS .............................................................. 8
NORMATIVE REFERENCES OF ISO AND OTHER INTERNATIONAL
ORGANIZATIONS ............................................................................................................ 9
INTERNAL NORMATIVE REFERENCES ........................................................................ 9
DEVIATIONS AND EXCLUSIONS ................................................................................... 9
DATA REQUIREMENTS ................................................................................................ 10
CLEAN-UP SAFETY, WORK RULES AND REGULATIONS .................................... 10
QUALITY CONTROL ...................................................................................................... 10
HEALTH, SAFETY AND ENVIRONMENTAL REGULATIONS ...................................... 10
2.
2.1
2.2
2.3
2.4
2.5
HANDLING AND STORAGE OF LINE PIPE AND OTHER MATERIALS .................. 12
PIPE HANDLING EQUIPMENT...................................................................................... 12
LOADING AND HAULING .............................................................................................. 12
UNLOADING................................................................................................................... 13
STORAGE OF LINE PIPE .............................................................................................. 13
STORAGE OF MATERIAL OTHER THAN LINE PIPE................................................... 13
3.
3.1
PRE-CONSTRUCTION SURVEY................................................................................... 14
PERMITTING .................................................................................................................. 15
4.
4.1
RIGHT OF WAY (ROW) ................................................................................................. 16
TEMPORARY ACCESS AND BY PASS ROADS .......................................................... 17
5.
STRINGING .................................................................................................................... 19
6.
6.1
6.2
6.3
6.4
6.5
BENDING OF PIPE ........................................................................................................ 20
BENDING MACHINES.................................................................................................... 20
PIPE OVALITY................................................................................................................ 21
BENDING INSPECTION................................................................................................. 21
FITTING BEND TO TRENCH ......................................................................................... 21
BENDING PROCEDURE................................................................................................ 22
7.
7.1
7.2
7.3
7.4
COUPLING – CLEANING - LAYING UP - BEVELING.................................................. 23
COUPLING ..................................................................................................................... 23
CLEANING...................................................................................................................... 23
LAYING –UP ................................................................................................................... 23
LINE-UP / BEVELING..................................................................................................... 23
8.
8.1
8.2
WELDING ....................................................................................................................... 24
PIPELINE INSTALLATION WITH CASING .................................................................... 24
WELDING OF CASING – VENTS AND BRANCH PIPE ................................................ 24
9.
9.1
9.2
9.3
9.4
9.5
EXCAVATION AND TRENCHING ................................................................................. 26
TRENCH IN SPECIAL LOCATIONS .............................................................................. 27
DRAINAGE OF THE TRENCH ....................................................................................... 27
TOPSOIL OR ORGANIC SURFACE MATERIAL CONSERVATION............................. 28
SPOIL MATERIAL .......................................................................................................... 28
TRENCH PROTECTION ................................................................................................ 28
10.
10.1
EXCAVATION BY BLASTING ....................................................................................... 29
BLASTING CRITERIA .................................................................................................... 30
eni spa
exploration & production division
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 5 of 59
11.
11.1
11.2
11.3
11.4
11.5
11.6
11.7
11.8
11.9
11.10
PIPELINE INSULATION................................................................................................. 32
GENERAL ....................................................................................................................... 32
ENVIRONMENTAL CONDITIONS ................................................................................. 32
PREPARATION OF THE SURFACES TO BE MANUALLY COATED ON SITE ........... 32
REMOVAL OF THE EXISTING COATING..................................................................... 33
PREPARATION OF THE AREA TO BE OVERLAPPED BY OTHER COATINGS ........ 33
INSULATION OF BARE SURFACES ............................................................................. 33
REPAIRS OF COATED .................................................................................................. 33
CHEEKS TO BE PERFORMED BEFORE LAYING ....................................................... 33
ROCKSHIELD PROTECTION ........................................................................................ 34
PROTECTION AGAINST ELECTRICAL OVERCURRENTS......................................... 34
12.
12.1
12.2
FIELD JOINT COATING ................................................................................................ 36
INSPECTION AND REPAIR OF COATING ................................................................... 36
REPAIR OF ANTICORROSION COATINGS ................................................................. 36
13.
13.1
LOWERING IN................................................................................................................ 37
ABOVE GROUND PIPELINE ......................................................................................... 38
14.
14.1
14.2
14.3
14.4
15.
15.1
15.2
15.3
15.4
15.5
15.6
15.7
15.8
15.9
15.10
15.12
BEDDING – PADDING AND BACKFILLING ............................................................... 40
BACKFILL MATERIALS.................................................................................................. 40
BACKFILL IN ROCKY AREA.......................................................................................... 41
BACKFILLING AT SPECIAL LOCATIONS..................................................................... 41
BACKFILLING PROCEDURES ...................................................................................... 41
PARALLELISM WITH EXISTING PIPELINE AND CROSSING OF
INFRASTRUCTURES .................................................................................................... 43
MAJOR WATERCOURSE CROSSING.......................................................................... 44
MINOR WATERCOURSE CROSSING .......................................................................... 44
WATERCOURSE BANKS SCOURING PROTECTION ................................................. 44
EROSION PROTECTION.............................................................................................. 45
MAJOR ROAD CROSSING............................................................................................ 45
MINOR ROAD CROSSING ............................................................................................ 46
HDD CROSSING ............................................................................................................ 46
RAIL WAY CROSSING................................................................................................... 47
TRENCHLESS CASING INSTALLATION FOR CROSSING ......................................... 48
PIPELINE AND UNDERGROUND CROSSING ............................................................. 49
PIPELINE CROSSING ROCKY STEEPED AREAS....................................................... 50
16
16.2
16.3
TIE-IN.............................................................................................................................. 51
FINAL TIE-INS ................................................................................................................ 51
PROTECTION AGAINST INDUCED VOLTAGE EFFECTS .......................................... 51
17.
17.1
17.2
17.3
CLEAN-UP AND LAND RESTORATION ...................................................................... 52
CLEAN UP ...................................................................................................................... 52
RESTORATION .............................................................................................................. 52
RESTORATION OF AGRICULTURAL AREAS.............................................................. 53
18.
18.1
18.2
18.3
18.4
INSTALLATION OF SPECIAL FITTINGS .................................................................... 54
GENERAL ....................................................................................................................... 54
INSTALLATION OF FLANGES....................................................................................... 54
INSTALLATION OF SHUT-OFF VALVES OR FITTINGS .............................................. 54
INSTALLATION OF INSULATION JOINTS.................................................................... 54
19
CATHODIC PROTECTION ........................................................................................... 56
20.
20.1
20.2
VALVE STATIONS......................................................................................................... 57
ABOVE GROUND PIPING ............................................................................................. 58
CORROSION PROTECTION OF ABOVE GROUND PIPING ....................................... 58
21
PIPELINE SIGNALLING ................................................................................................ 59
eni spa
exploration & production division
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 6 of 59
22
TELECOMUNICATION CABLE AND FACILITIES ....................................................... 59
23
COMPLETION OF CONSTRUCTION WORK ............................................................... 59
eni spa
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 7 of 59
exploration & production division
1.
GENERAL
This Specification defines the minimum design and production requirements for the buried
pipeline’s construction
The construction shall include installation of all pipeline and the associated facilities such as
block valves, Pig Traps, casing pipe, fittings, prefabricated bends, cathodic protection test
leads, anchor flanges (if any), telecommunication cable, pipeline markers and warning
signs, etc.
The present Specification is relevant to the mechanical and civil work of the pipeline, within
the onshore pipeline battery limits
Any applicable Construction Code or Government Regulations may prevail on this
specification when more stringent.
The CONTRACTOR shall determine the most severe requirements or combination of
requirement and shall inform the Company if any deviation from this specification is deemed
necessary to comply with national and/or local regulations. Any matter relevant to safety,
environmental, economic and legal aspects has to be considered.
1.1
PARTIES INVOLVED IN THE ENGINEERING ACTIVITIES.
The following Parties are involved in the Project activities:
COMPANY
CONTRACTOR
SUB-CONTRACTOR
VENDOR
Eni spa – exploration & production division or
Affiliated Company
The Company who is awarded the Contract,
responsible for doing the Work.
Any organization who supply services of any
kind to Contractor
Any organization who supply material and/or
equipment to Contractor.
eni spa
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 8 of 59
exploration & production division
1.2
ACRONYMS
API
CEP
CPS
ESIA
FEED
FOC
HSE
ISO
BVS
MAOP
NDT
ROW
RTU
SCADA
SI
SMYS
SMTS
UTM
WT
D.C.
DCVG
CP
1.3
American Petroleum Institute
Construction execution plan
Cathodic Protection station
Environmental and Social Impact Assessment
Front End Engineering Design
Fiber Optic Communucation System
Health, Safety, Environment
International Standards Organisation
Block Valve Station
Maximum Allowable Operating Pressure
Non destructive test for Welding
Right of way
Remote Terminal Unit
Supervisory Control and Data Acquisition
International System of Units
Specified Minimum Yield Strength
Specified Minimum Tensile Stress
Universal Transversal Mercator Coordinates
system
Wall Thickness
Direct Current
Direct Current Voltage Gradient
Cathodic Protection
UNITS OF MEASUREMENT
International System (SI) of units shall be used, however, pressure shall be in bar(g).
Code’s figures specified in inches are to be converted to the nearest integer value in
millimetres with exception for pipe diameter and pipeline where double indication in inches
and millimetres is required.
1.4
INTERNATIONAL CODES AND STANDARDS
The construction work shall fully comply with the latest edition of the listed Codes and
Standards, unless otherwise amended by this specification. In case of conflict or ambiguity
the most stringent shall apply.
Compliance with this Specification shall not relieve CONTRACTOR of his responsibility to
carry out the work and supply equipment suited to meet the specified service conditions and
applicable regulations.
Where conflicts exist between this Specification and others drawings, standards codes and
specifications, the most stringent shall be applied.
The main reference codes, basis of design are listed here below.
eni spa
exploration & production division
1.5
NORMATIVE REFERENCES OF ISO AND OTHER INTERNATIONAL ORGANIZATIONS
ASME B31.4
Pipeline transportation system for liquid Hydrocarbons and
other Liquids
ASME B31.8
Gas transmission and distribution piping system
API 5L
Specification for line pipe
API 1104
API RP 1102
Welding of Pipelines and Related Facilities
Recommended Practice for Liquid Petroleum
Crossing Railroads and Highways
ANSI / ASSE A10.7
Safety Requirements for Transportation, Storage, Handling and
Use - Commercial Explosives and Blasting Agents – 2011
ISO 13623
Petroleum and natural gas industries – Pipelines transportation
System
Preparation of steel substrates before application of paints and
related products — Visual assessment of surface cleanliness —
Part 1: Rust grades and preparation grades of uncoated
steel substrates and of steel substrates after
overall removal of previous coatings
ISO 8501-1
1.6
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 9 of 59
Pipelines
INTERNAL NORMATIVE REFERENCES
02776.PLI.MEC.SPC
00300.PLI.COR.SDS
20000.VAR.PAI.FUN
07423.PKG.GEN.SDS
0324.TEMM.REL.0
03517.PLI.MEC.SDS
27956.PLI.COR.SDS
03518.PLI.MEC.SPC
Field Welding of Cross-country Pipelines
Transportation and gathering pipelines – Monolithic insulating
joints
Protective coating, galvanising and metallising for internal and
external surfaces of offshore and onshore structures and
related components
Inspection and Tests for Package Supplies
Guideline for NDE during Projects Development Phases
Hydrocarbon pipelines – Hydrostatic testing of pipelines
Guideline for Monitoring of Onshore Pipeline
Preparation of “As-Built” Drawings
Should there be conflict between the requisition, data sheets, specifications, codes and
standards or lack of clear definition as to the applicability of any specification or standard,
the CONTRACTOR shall obtain a written clarification from the Company before proceeding.
In case any incongruence or redundancy of information arises between ISO and other
standards, it is necessary to comply with ISO standards.
In case of multiple language specifications the English version shall take precedence should
there be any conflict between English and other versions of the applicable documents.
1.7
DEVIATIONS AND EXCLUSIONS
Unless deviations/exclusions are specifically identified by the CONTRACTOR in the bid
proposal and written agreed by the Company, the CONTRACTOR shall be deemed to have
confirmed full compliance with all the documents listed.
eni spa
exploration & production division
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 10 of 59
Any mismatch in between Contractual Reference Documents, and or with this Specification,
shall be reported to the COMPANY, and unless otherwise agreed or decided by the
COMPANY, the more stringent requirement shall apply.
Exceptions to, or deviations from this specification are not permitted unless previously
accepted in writing by the COMPANY.
1.8
DATA REQUIREMENTS
CONTRACTOR shall submit the following data to COMPANY as part of the Scope of Work:
• Construction Execution Plan
• Construction method of Statements for each construction phase
• Full quality control package;
• Quality Control Program (QCP) for review prior to commencement of work;
• All necessary QCP documentation including; certification and calibration tests,
equipment as Work is completion;
CONTRACTOR's performance of their obligations hereunder shall not be deemed complete
until COMPANY is in receipt, on proper forms, of all Technical Data and other documents to
be submitted to COMPANY as part of CONTRACTOR's Scope of Work. Failure of
CONTRACTOR to comply with the above data requirements will entitle COMPANY to
withhold any progress payment, or final payment, pending COMPANY’s receipt of all the
above data.
CONTRACTOR shall maintain at the jobsite up-to-date copies of all drawings,
specifications, and other documents and supplementary data, complete with latest revisions
thereto. In addition, CONTRACTOR shall maintain a continuous record of all field changes.
1.9
CLEAN-UP SAFETY, WORK RULES AND REGULATIONS
CONTRACTOR shall perform the Work in a safe manner and keep the work site in a clean condition
all in accordance with the Contract and shall comply with all work rules and regulations.
CONTRACTOR shall submit a Safety Plan within seven (7) calendar days of award of this
Contract.
1.10
QUALITY CONTROL
CONTRACTOR shall be responsible for the performance of all inspection and testing activities
as specified in the contract. CONTRACTOR shall submit the Quality Program and Inspection
Procedures required in this Attachment within seven (7) calendar days of award of this
contract.
CONTRACTOR shall take instruction from COMPANY if COMPANY considers that quality is
not reaching the required standards.
1.11
HEALTH, SAFETY AND ENVIRONMENTAL REGULATIONS
The CONTRACTOR shall be responsible for ensuring that works and services meet all
applicable regulations on health, safety and environmental issues.
The Pipeline and the associated Facilities shall be designed to operate safely and
satisfactorily at all expected combinations of process, utilities, climates and environmental
conditions.
CONTRACTOR shall apply proactive health, safety and environmental management
systems and risk management processes in accordance with COMPANY’s requirements.
eni spa
exploration & production division
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 11 of 59
Without relieving CONTRACTOR of any of its obligations, COMPANY may take part, to any
degree it deems necessary, in the control and removal of any hazardous material, pollution,
contamination or environmental risk which is the responsibility of CONTRACTOR under this
CONTRACT or APPLICABLE LAW.
eni spa
exploration & production division
2.
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 12 of 59
HANDLING AND STORAGE OF LINE PIPE AND OTHER MATERIALS
CONTRACTOR shall transport all project materials, such as line pipes, hot bends, valves,
fittings, flanges, scraper traps and any other materials as per Contract agreements, to the
installation sites, and shall include all handling operations.
Handling of pipe and other materials shall include all operations by which pipe and material
are handled, such as loading, unloading, hauling, stringing, laying, lowering-in, etc. and all
lifting or lowering from one level to another.
Pipe shall always be handled with care, using suitable equipment to prevent damage to pipe
walls, pipe ends and pipe coating. Pipe shall not be dropped, thrown, dragged, skidded,
rolled or handled with unsuitable equipment.
CONTRACTOR’s material handling equipment and storage facilities shall be subjected to
review by COMPANY. Any equipment or storage facility that COMPANY considers unsafe
or unsuitable shall be replaced by CONTRACTOR as instructed, and other suitable means
of protection and prevention of damage shall be provided.
2.1
PIPE HANDLING EQUIPMENT
CONTRACTOR can use the following lifting system respecting the safety and protection
condition.
Pipe shall always be handled using special pipe handling equipment suitable for the specific
pipe size being handled including the Vacuum Lift if available. Coated pipe shall be handled
with wide canvas or nylon slings. Bare cables, chains, hooks, tongs, metal bars and other
unpadded equipment shall not be allowed to come into contact with the coated pipe
surfaces. Coated pipe shall only be supported on padded skids or other padded supports,
such as plastic covered earth berms.
Belts and slings shall have a minimum width equal to the pipe diameter and shall provide
pipe-to-sling interior angles of thirty (30) degrees minimum, and shall be of a design that
permits rapid and easy removal, such as removable pin and clevis on one end. Damaged or
worn belts or slings shall be discarded.
Lifting shoes shall be of malleable iron or other approved material and shall have surfaces
coated with belting material, brake lining, plastic or other approved material. They shall be at
least 100 mm wide and shall be properly shaped and sized to engage at least one tenth
(1/10) of the internal pipe diameter.
End hooks shall have smooth faces and be of a type and material that will not cause
damage or contaminate the weld surface of the pipe. They shall be shaped to properly fit the
curvature of the inside of the pipe. The cable angle to the vertical shall not exceed 45°
without the use of a spreader bar.
2.2
LOADING AND HAULING
Pipes shall only be loaded and hauled on flat bed trucks or special pipe trailers fitted with
bolsters padded with tough pliable material. The bolsters shall be of a suitable width and
shape to evenly distribute pressure on the pipe. They shall preferably be shaped to support
at least thirty (30) degrees of arc of the circumference of the pipe. Metal bolsters shall not
be used. Steel banded truck beds shall be padded, or suitable wooden skids with padding
shall be properly placed on such trucks.
The lowest tiers of pipes shall be laid on the bolsters and subsequent tiers shall be laid with
adequate padding between the pipe layers. Metal to metal contact shall be avoided.
Each length of pipe shall be lowered into position without dropping in order to nest evenly
with the other lengths. Sudden impact between lengths of pipe or between pipe and other
objects shall be avoided.
Each load of pipe shall be tied down using ties of suitable proportions and strength,
arranged in such manner that tie-down is achieved over the bolsters. Tie-downs shall be
well padded with rubber or similar material, or padded blocks shall be used between the
pipe lengths and ties. After the pipe load has been hauled a short distance, any tie-downs
that become loose as a result of load settling shall be re-tightened.
eni spa
exploration & production division
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 13 of 59
To avoid damage to pipes by rocks or other debris thrown up during transit, suitable
protective covers shall be placed over the outside of the pipes when they are on a truck or
trailer.
2.3
UNLOADING
Pipe shall be unloaded from trucks using a Vacuum lift, side-boom tractor, crane, suitable
lifting equipment with padded bars or grips. The pipes remaining on the truck during
unloading shall be kept under strict control at all times.
In rocky areas and in unlevelled terrain, pipe shall be unloaded onto suitable pads, padded
skids, or plastic covered earth berm to avoid damage from rocks and uneven load
distribution.
2.4
STORAGE OF LINE PIPE
CONTRACTOR shall issue a Method of statement for COMPANY approval, before to store
all the material. CONTRACTOR may stockpile pipe on the ROW (Right-of-Way) or at
permitted storage locations. CONTRACTOR shall submit a stacking plan to COMPANY for
approval. The height of the pipe stack shall not exceed the limit allowed.
The pipe joints shall be placed on padded timber skids or plastic covered earth berms off
the ground at a height that will maintain the pipe above the level where surface or run-off
water may contaminate the pipe bevels or flow through the stored pipe. The contact area of
pipe and skid and the skid spacing under the pipe shall be sufficient to prevent denting or
permanent deformation of the pipe. Skids shall not be less than 100 mm wide. Pipes on
skids shall be chocked and blocked to prevent shifting.
CONTRACTOR shall protect the external coating of pipe from ultraviolet degradation during
storage and during all other stages of construction where pipe is to be left exposed to
sunlight for a cumulative period longer than 150 days. Methods of protection shall be in
accordance with the coating manufacturer’s recommendations.
Pipe of different grades or wall thicknesses shall be segregated and stored in such manner
as to avoid mistakes the wrong pipe.
2.5
STORAGE OF MATERIAL OTHER THAN LINE PIPE
Material such as coating material, welding electrodes, cement, paint, chemicals, etc., which
are liable to deteriorate, change their properties or characteristics, or be damaged by
exposure to weather, humidity, extremes of temperature or other adverse weather
conditions, shall be suitably stored and protected from adverse exposure.
CONTRACTOR shall conform strictly to the manufacturer’s instructions regarding storage
temperature and other conditions for all materials. Where necessary, he shall also provide
temperature and humidity controlled storage facilities.
Valves, flanges and fittings shall be handled in such a manner as to prevent damage to
shafts, facings, bevels and machined surfaces. Valve ends shall be temporarily sealed by
wooden plugs, blanking plates, plastic caps or other approved methods to prevent the entry
of dirt. When valves, flanges and fittings are stored outdoors, they shall be arranged on
skids off the ground in an orderly manner.
All the sensitivity material as electric & electronic devices, meters, gauges etc. shall be
stored inside a dedicated heated building.
Flange faces and all machined surfaces shall be covered with grease to protect them
against rust and corrosion.
eni spa
exploration & production division
3.
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 14 of 59
PRE-CONSTRUCTION SURVEY
Prior to commencement of any construction activities, a pre-construction survey shall be
carried out to refresh and mark with stakes the pipeline centreline and the Right-Of-Way
(ROW) boundaries.
Pre-construction survey will be required to establish or confirm as a minimum, the following:
•
•
•
•
•
•
•
•
•
Temporary bench marks
Intersection (Turning) Points and deflection angles
Pipeline centre line location and chainage
Right of Way (ROW) boundaries
Pipelines, services, roads, railways and watercourses crossings
Locations of buried and above ground obstacles
Location of AGI (Above ground Installation) and pipeline associated facilities
Locations of cathodic protection test stations
Boundaries of wet areas
Reference points shall be established every 100 metres and offset along ROW boundary
limits. Stakes shall be placed at 50 m intervals and at all points of intersection. The
numbering system shall be a continuous progressive numbering.
The staked points shall be tied into the co-ordinates system established for the project.
CONTRACTOR shall be responsible for ensuring that the monuments established along the
pipeline route are maintained during ROW preparation.
CONTRACTOR shall not commence any Construction Work on the easement until the
ROW staking has been approved by COMPANY.
Any legal survey markers shall not be disturbed, defaced, altered, destroyed or removed. If
this should occur, the marker shall be replaced by a local professional land surveyor.
Information regarding the location of legal survey markers in the field shall be obtained by
CONTRACTOR before proceeding with Construction Work.
All foreign structures crossed by the pipeline or running parallel at a close distance, shall be
located and protected in accordance with the requirements of this specification.
The location of underground and/or overhead facilities shall be staked on both sides of the
ROW and at the crossing points. CONTRACTOR shall notify and liaise with owners /
operators of all foreign facilities in accordance with the requirements of this specification.
Survey work and staking associated with the ROW location shall include, but not be limited
to:
• temporary sites;
• access road to ROW;
• spoil disposal sites;
• extra work areas, such as at crossings.
As part of the pre-construction survey, CONTRACTOR shall liaise with the landowners to
identify the areas that may require temporary fencing. Agreement as to the type of
temporary fencing shall be reached with the landowners.
CONTRACTOR shall maintain a surveying team at the work site. The team shall be
responsible for establishing the location of the pipeline and other work in the right of way, for
replacing any disturbed stakes, for executing the work to the line and grade, for the marking
of as-build information on the drawings and for others work as necessary.
eni spa
exploration & production division
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 15 of 59
CONTRACTOR shall mark, flag out the location and establish voltage rating of overheads
power lines when they cross or encroach within 150 m. of the right of way . CONTRACTOR
shall be take suitable precautions such as the use of watchmen and adequate warning tape,
such as aerial markers for the passing of plant and equipment below overheads power lines,
to ensure safe working in the vicinity of overheads lines. CONTRACTOR shall submit a
crossing plan and drawing for approval showing the suitable safety precautions.
3.1
PERMITTING
CONTRACTOR shall obtain all required field pass/permits and authorization to perform the
work at his own expense. CONTRACTOR is responsible to apply for, receive and maintain
all permits required, in good standing, for work and employees in the areas of pipeline and
associated facilities installation. All permit requirements for the execution of the Contract
shall be the responsibility of CONTRACTOR.
Copies of all permits and regulatory findings shall be forwarded to CONTRACTOR prior to
work commencing, relating to any individual permit or planned occupation of work site.
eni spa
exploration & production division
4.
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 16 of 59
RIGHT OF WAY (ROW)
The ROW dimensions shall be in accordance with the project drawings.
CONTRACTOR can define a different width of the ROW in accordance with the pipe laying
methods adopted. CONTRACTOR shall submit the proposed solution and the width of the
ROW to COMPANY for approval. Any widening of the ROW at each crossing must be
communicated to and approved by COMPANY as well.
ROW shall be cleared and graded only where necessary and then only to the extent
required to execute the pipeline construction operations efficiently and to allow easy transit
of construction equipment and pipe trailers onto and along the ROW.
Before clearing, grading and topsoil stripping on the ROW, CONTRACTOR shall move
survey stakes back to the edge of the ROW and preserve them during all phases of the
work for use in reporting progress and locations along the line. CONTRACTOR shall be
responsible for relocations trench centreline and shall pay the cost of replacing survey
stakes that have been destroyed.
The ROW shall be cleared of all boulders, rocks and any other materials that would interfere
with pipeline construction operations.
All sharp points and hollows in the ROW shall be graded off to minimise the bending of pipe.
All irregularities in the ground surface shall be graded to facilitate the passage of
construction equipment.
Grading shall be performed in such a manner as to minimise interference with existing
natural drainage. All grading shall be finished to maintain the original grade of the ground
and the original drainage or flow conditions.
CONTRACTOR shall arrange the maintenance and servicing of work equipment and
vehicles so to Keep the right of way and adjacent land free of gasoline, diesel and discarded
parts.
Right of way and adjacent land shall be keep free of all debris brought onto the job by
CONTRACTOR including but not limited to waste ,oil, grease cartridges, oil cans, containers
skid, scraps pipe, or cutting, coating material and welding electrodes. Each work crew
shall be responsible for cleaning up its debris on a daily basis. Such debris shall disposed of
as approved by COMPANY. Drip tray shall be use for static plan to prevent oil
contamination of the soil. Portable toilette shall be install along the right of way.
Waste handling and disposal shall be in accordance with CONTRACTOR approved Waste
Management Plan.
The pipeline right of way shall be cleared and graded only to the extent required for
performing the pipeline construction operations efficiently, and only the minimum width
required to permit easy movement of construction equipment and pipe trailers along and
onto the right of way.
Clearing and grading operations, including the disposal of the material overburden
generated from these operations, shall be performed in such manner as to minimize
environmental damage.
Any damage done to private or public facilities resulting from the clearing and grading
operations shall be repaired immediately unless COMPANY permits such repairs to be
performed by the clean-up crew at a later stage. All repairs to damaged facilities shall be
CONTRACTOR’s own account.
Clearing and grading of river banks, for a minimum 10 m. back from the water edge, shall be
restricted until, immediately before work is to commence on the crossing installation.
eni spa
exploration & production division
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 17 of 59
The right of way shall be cleared of all vegetation and other material that would impede or
interfere with the pipeline construction operations.
Note:
The use of herbicides in the clearing operation is be strictly forbidden.
Clearing of vegetation such as brush, stumps and other similar debris shall be disposed of
in accordance with COMPANY instructions. Where disposal by burning is not permitted
,clearings shall be completely removed from the right of way and disposed of by other
means acceptable to COMPANY.
CONTRACTOR shall ensure that adequate fire fighting tools and equipment, fire
extinguishers, and a water truck are on site in the event that a fire does get out of control.
Loose debris shall be cleared within the right-of-way corridor a sufficient distance from the
trench line so that the excavated material will not fall on foreign matter that is unacceptable
for backfilling the trench and which might become mixed with the excavated soil.
Disposal of clearing shall be carried out prior to the grading operation and none of it shall be
left for the final clean-up operation.
There may be certain locations on the right of way that will require Contactor to work in
restricted width working areas.
CONTRACTOR may request a larger working width subject to approval by COMPANY. All
roads and watercourses, dry streams or otherwise shall be crossed utilizing the minimum
working right-of-way width possible in order to minimize the amount of installed erosion
control measures.
4.1
TEMPORARY ACCESS AND BY PASS ROADS
Temporary access roads shall be included in CONTRACTOR works and shall be submitted
to COMPANY approval.
CONTRACTOR shall submit his plans for these access roads well in advance of his needs
and shall prepare all necessary documentation required, and assist with any special permits
to be obtained by COMPANY.
During the whole duration of construction work, CONTRACTOR shall maintain the access /
service roads in such a way to ensure the safety continuous passage of vehicles to
supporting the construction activities
Temporary access roads to or from existing access to the ROW or from the ROW to other
work areas, such as spoil disposal sites, shall be developed, constructed, maintained and
subsequently reinstated by CONTRACTOR. The access road shall be reinstated to a
condition at least equal to that existing before commencement of the works.
The suitability and condition of existing access roads and tracks, to be used as temporary
access roads, shall be examined prior to any upgrading or reinstatement.
CONTRACTOR shall make due allowance for restriction placed by local Authorities or
Governing Bodies on movement of vehicles.
Development and maintenance of temporary access roads shall conform to the following:
•
•
•
•
Activities shall be conducted in such a manner as to minimise disturbance to
watercourses, drainage and dyke structures;
Cuts and grades in unstable areas of soil subjected to erosion shall be avoided
unless absolutely necessary;
Culverts, of an approved type, shall be installed as required or where such access
roads are to be left in place during the lifetime of Construction Works;
Access roads shall be left in situ or reinstated in accordance with the landowners
requirements or other approved instruction.
eni spa
exploration & production division
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 18 of 59
Construction traffic shall not pass over an existing pipeline, except at specific crossing
points previously agreed with COMPANY. CONTRACTOR shall fence-off the crossing
points on both sides over the agreed width. The crossing points shall be clearly marked.
CONTRACTOR shall build temporary crossing ramps at the crossing points.
eni spa
exploration & production division
5.
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 19 of 59
STRINGING
Pipe shall not be strung more than two (2) kilometres in advance of mainline welding, unless
agreed by COMPANY. Pipe shall be strung only on construction ROW which has been
cleared and, where necessary, graded.
Pipe shall be placed at a suitable distance from the staked trench line and strung in proper
quantities to avoid moving pipe forwards or backwards along the line.
CONTRACTOR shall distribute the various pipe joints according to the Construction plan.
Pipe shall not be strung directly on the ground but shall be placed on sand bags or padded
skids.
Pipe and material shall be strung in a manner that will cause the least possible interference
with the normal use of the land being crossed. Gaps shall be left between adjacent lengths
of pipe at suitable intervals and at well-defined trails to allow the free passage of vehicles
during the time interval between the stringing and other construction operations. Pipe
stringing shall be done in such a manner that it will not cause a hazard to traffic or be
subjected to possible damage by traffic.
Careful unloading and stringing procedures shall be followed to avoid damage to the pipe or
pipe coating. Line pipe will be strung directly from the trailers to the installation location
except where it is unsafe to unload, i.e. on special sections or gradients of 15o or more. At
sharp gradients the line pipe will be loaded directly from the trailers to a tracked stringing
tractor to carry 1 or 2 pipes. Unloaded pipe shall be supported above ground level in a
manner that will prevent rain, runoff water and sediment from entering the pipe, as well as
preventing damage to the pipe ends and coating.
On special sections the line pipe sections will be stored in a nearby holding / stringing area
where all preparatory works will be completed prior to stringing / welding. The trailers will be
unloaded in this area
In the rocky area, the pipes will be strung after completion of drilling, blasting and
excavation to required elevation so as to eliminate any possibility of pipe damage.
CONTRACTOR shall record the pipe joint numbers, pipe lengths and location of each piece
of pipe, as strung. These records shall be amended “as laid” and shall include the weld
numbers.
The pipe shall be strung end-to-end and the pipe ends carefully lined-up for welding, using
suitable line-up clamps to ensure accurate alignment and spacing. Internal line-up clamps
shall be used. However, external clamps may be used when it is impractical to use internal
clamps, such as at tie-in welds.
Hammering of the pipe to obtain proper line-up will not be permitted.
No pieces of pipe shorter than two (2.5) metres in length may be incorporated in the
pipeline.
After the pipes have been strung, they shall be inspected and all defective pipe ends
repaired.
eni spa
exploration & production division
6.
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 20 of 59
BENDING OF PIPE
CONTRACTOR shall perform cold pipe bending in the field as required to accommodate
changes in the slope and in the horizontal alignment of the cold pipeline.
Sag bends and over-bends shall be used at changes in the vertical alignment (slope) of the
pipeline and side bends at changes in the horizontal alignment. Composite bends shall be
installed at points where both the vertical and horizontal alignment of the pipeline occurs
simultaneously.
Bending of pipe shall be kept to a minimum and shall only be performed where changes in
slope are such that the pipe will not be laid naturally on the bottom of the trench, and at
definite changes in the horizontal alignment. Pipe bending shall not be resorted to for
correcting irregularities in the trench. Trench conditions shall be corrected to maintain the
straight-line vertical and horizontal alignment of the pipeline and to restrict field bending of
pipe where it is absolutely necessary.
The location of pipe bends shall coincide with the points of change in slope or direction. The
location and degree of each bend shall be determined during construction at the work site
after the trench has been excavated. Bends shall be made near the trench at the locations
for which they are intended. Bends shall be made ahead of the laying crew.
All pipe-bending operations shall be performed under the supervision and direction of a
competent engineer who shall have the responsibility of determining the required angles
and curvatures of pipe bends.
All field bends shall be made only by the cold, smooth stretch method, using an approved
bending machine of proper size. The use of heat to produce field bends is prohibited.
Wrinkle bends and mitre bends in product pipes are strictly prohibited. COMPANY shall
approve the method and procedure of field bending.
For sag bends and over bends, the weld seam shall be near the side, and for side bends the
weld seam shall be the top. Precautions shall be taken not to have the longitudinal weld
seam pressed upon by the bending shoes. The longitudinal weld seam of the pipe shall be
at a location such that it will be in the top quadrants of the pipe after it is laid in the trench
(i.e. the seam weld shall not face toward the bottom of the trench.)
The longitudinal weld seam of the pipe shall not be in line with the longitudinal weld seam of
an adjacent pipe but shall be off set a minimum 100 mm (4 in). The weld seam of the
adjacent pipe shall also be in the quarter of the pipe.
Note: Bending at site by Heating is strictly forbidden
6.1
BENDING MACHINES
Bending machines shall be suitable for bending pipe of the size involved and shall be fitted
with the correct shoes and internal mandrels for the specific pipe size. Bending machines
shall be subjected to approval by Company. CONTRACTOR shall replace any bending
machine rejected by COMPANY.
The bending machine and bending procedure shall be capable of producing smooth bends
without wrinkles and with minimum flattening of the pipe. Extreme caution shall be exercised
in the use of the mandrel in order not to increase the diameter of the pipe.
The surfaces of the bending machine that come in contact with the pipe (shoes, rollers,
mandrel, etc.) shall be suitably padded so that they will not damage the pipe coating.
eni spa
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 21 of 59
exploration & production division
6.2
PIPE OVALITY
The ovality (flattening) of a bent pipe shall not exceed 2.5 % of the nominal diameter at any
point in the bend, including the ends. Ovality is defined as the difference between the
maximum and minimum inside diameters of the pipe compared with the nominal internal
diameter:
Ovality =
6.3
(ID max− ID min )
IDno min al
BENDING INSPECTION
Each completed field bend shall be inspected in the presence of COMPANY prior to welding
in the line.
All bends shall be visually inspected for any evidence of buckles, wrinkles, distortion, dents,
gouges, grooves, nicks, cracks and any other mechanical damage.
All bends shall be checked with callipers to ensure that any ovality of the pipe is within the
tolerances.
Any bend that fails the ovality check or that exhibits any sign of mechanical damage, as
specified above, will not be allowed to be inserted in the pipeline and shall be removed from
the site and replaced by a new bend. Hammering or the use of jacks to reform a buckled or
deformed pipe bend shall be strictly prohibited.
Pipe coating shall be inspected for damage caused by the bending operations. The coating
shall be inspected for holidays and for disbonding.
Any defects or disbonding of the pipe coating caused by the bending operation shall be
repaired in accordance with the procedure provided for by CONTRACTOR and approved by
COMPANY.
Any defects such as cracks or disbonding within the coating caused by the field bending
operation shall be investigated and the bending procedure shall be modified to minimise
such defect.
6.4
FITTING BEND TO TRENCH
Bends shall conform reasonably to the bottom of the trench i.e. bends shall fit the trench
without the need of force to hold them in place. When requested by COMPANY,
CONTRACTOR shall set the bend in the trench in advance of the laying crew in order to test
the bend conformance to the trench with respect to bend angle and radius.
Bends shall be made in such a manner that the backfill will tend to close rather than open
the bend. For over bends, the crotch of the bend shall be in contact with firm soil. For sag
bends, the legs of the bend shall be supported by firm soil. For side bends, the minimum
clearance of 200 mm shall be left between the side of the bend and the inner wall of the
trench.
Bends that do not conform reasonably to the trench bottom will be rejected.
Where authorised by COMPANY, CONTRACTOR may correct the shape of the trench as
necessary to accommodate the bends in a satisfactory manner to COMPANY. Irregularities
in the trench, such as highs and lows, may be corrected by filling the trench bottom with
suitable, loosely packed, clean earth or sand, provided this fill does not exceed 150 mm in
depth.
eni spa
exploration & production division
6.5
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 22 of 59
BENDING PROCEDURE
Before starting any work, CONTRACTOR shall submit and demonstrate to COMPANY a
bending procedure that shall conform to the recommendations of the manufacturer of the
bending machine. The procedure shall include the lengths, maximum degrees per pull and
the method and accuracy of measurement during pulling of the bend. This procedure shall
be subjected to COMPANY approval.
CONTRACTOR shall not apply a bending radius of less than 40 x DN, unless approved by
COMPANY.
Bending shall not be performed on the pipe within a minimum distance of 1 OD from the end
of the pipe. In other words, a straight pipe section at least 1 OD long shall be left on each
side of the bend.
If the pipe used to produce a bend is made up of two pipes welded together, bending shall
not be carried out closer than two metres on either side of the welded joint.
Suitable precautions shall be taken to prevent the bending operation from causing out-ofroundness at the ends of the bent pipe that exceeds the ovality limits.
Pipe bends shall not be straightened after bending to correct the bend angle. Deformation of
the pipe material shall be performed in one direction only in order to ensure that bidirectional yielding of the steel does not occur.
CONTRACTOR shall keep records of all field bending of pipe performed during the
construction of the pipeline.
The records shall include details of location, pipe size, pipe number, and angle of bend of all
field bends.
eni spa
exploration & production division
7.
7.1
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 23 of 59
COUPLING – CLEANING - LAYING UP - BEVELING
COUPLING
Before coupling the pipes to be welded, the CONTRACTOR shall clean every single pipe
inside by a scraper capable of removing any dirt or foreign matter.
The scraper however shall not damage the internal lining, if any.
7.2
CLEANING
The interior of each pipe length shall be carefully inspected for the presence of dirt, loose
mill scale, or other foreign matter before being lined-up for welding. The interior shall be
cleaned with a suitable swab, with compressed air, by running cleaning pigs through or by
any other means acceptable to COMPANY. Cleaning shall be done on the same day the
length is welded on line.
7.3
LAYING –UP
Laying-up of the pipe sections alongside the trench or near supports for cleaning, welding
and inspection of the pipe coating prior to lowering the welded pipe sections into the trench,
shall be done in such manner as to prevent any damage to pipe or pipe coating and to
permit the subsequent operations to be carried out in an efficient manner.
Extreme care shall be exercised to ensure that bent sections of pipe are laid at the position
relative to the trench for which they were bent. The pipe shall be laid in such manner that
when pipe is lowered the bends will rest in the trench at the proper location.
Pipe shall be placed on padded timber skids parallel to the trench and at a sufficient height
above the ground to permit adequate clearance for the cleaning, welding and coating
inspection operations. The skids shall be spaced at close enough intervals not to allow the
pipe to sag excessively between the skids.
Skid stacks shall be stable enough so that pipe movement due to expansion and contraction
will not cause the skids to move or pipe to creep off the skids. The pipe shall be properly
cradled and blocked on the skids in a manner that will prevent the welded sections from
creeping off the skids.
7.4
LINE-UP / BEVELING
CONTRACTOR shall prepare the bevel for all diameter pipe. No claim shall be made by
CONTRACTOR to COMPANY by reason to prepare the bevelling before or after the
automatic or manual welding. The equipment used for bevel facing and cleaning, such as,
mechanical cutting, grinding, brushing, etc, shall not cause any detrimental metallurgical
effects to the edges to be welded. Accordingly, arc air gouging, flame gouging and chipping
shall not be permitted. Bevel facing may only be carried out by mechanical means (bevel
face cutters) or by flame cutting. Edges of faced bevels shall be left free of slag and debris.
Fitting and pipe ends, when bevel faced ,shall be regular and faced to correct angle in
accordance with applicable welding procedure specification.
Bevel repair by welding shall not be permitted.
eni spa
exploration & production division
8.
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 24 of 59
WELDING
The CONTRACTOR shall carry out the circumferential weld (weld joint) to connect the
pipes, the fittings and the equipment to be inserted in the pipeline according to the
provisions set forth in the relevant specification and annex mentioned in the contract
documents.
The joined pipes shall be laid on wooden supports and bags filled with loose earth or sand.
If the type of coating and the ambient temperature do allow it, the CONTRACTOR can lay
the pipeline on heaps of earth free from stones or sharp and hard bodies which might
damage the coating, before lowering it in the trench.
At the end of each working day and whenever the coupling and welding operations are
jointed section with watertight caps of the type approved by the Client's representative.
The cap shall be placed and removed without causing
damages to the pipe bevels; the
removal shall only be possible using an adequate equipment.
The caps shall be kept onto the pipe end throughout the interruption; therefore the caps at
the crossings and at the ends of the jointed sections shall be removed when tie-ins are
performed.
8.1
PIPELINE INSTALLATION WITH CASING
The CONTRACTOR shall install the casing whenever required by the project documents or
by the Client’s Representative.
The installation can either be performed according to the trust boring method or in open
trench, depending on the obtained and on the instructions given. The installation of the
casing in open trench shall be preferred whenever possible and permitted.
The casing shall be installed according to the trust-boring method in railway, highway, water
channels and heavy traffic road crossings.
The commencement of works shall be notified to the Client's Representative, and
confirmation of the possible provisions shall be obtained from the competent Authorities.
Before coupling the casing pipes, the CONTRACTOR shall make sure that the internal
painting, if any, is sound, and shall make the necessary repair if required by the Client's
Representative.
The pipes shall be checked before welding to make sure that they are free from ovalizations
or dents. Such defects shall be repaired by hammering.
Should it be not possible because of the extent of the damage, the defective pipe section
shall be cut-out using adequate equipment (manual cutting is not permitted)
The head shall be re-bevelled according to ASME B31.8 or B31.4 assuming the
orthogonality to the pipe axis.
8.2
WELDING OF CASING – VENTS AND BRANCH PIPE
The welding of the casing and vent pipes shall be performed by the CONTRACTOR
according to the modalities approved by the Client's Representative before commencing the
works, while the welds shall be just visually inspected.
The welds shall be performed by qualified welders at least for the filling passes of line pipes.
The weld shall not fill the bevel completely with the required number of passes. If the
diameter does allow it, the weld bead inside the casing shall be grinded off by removing any
protusion.
In the event of open trench crossing the welding operations shall be carried out before
opening the trench and the casing pipes shall be lowered-in immediately after.
Vent and drain pipes shall be installed by the CONTRACTOR by direct insertion and
welding onto the ends of the casing before introducing the line pipes. The assembly of
pipes, threaded and welded fittings and vents shall comply with the project documents.
eni spa
exploration & production division
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 25 of 59
The points where the vents and drains come out of the ground shall be those shown in the
drawing or specified by the Representative during the works.
The CONTRACTOR shall prevent the vents and drains form touching the pipeline keeping
the parallel section at a distance of at least 20 cm by means of insulating collar spacers.
Sleepers, wood wedges or steel brackets shall not be used, even temporarily, to guarantee
the said spacing. The vents or drains shall never be fastened or supported with metal wires
or ropes wound around the casing pipes, line pipes or other close structures.
The buried section of vents and drains shall be coated to a height of 30 cm from the ground
level. The above ground section over the 30 cm height shall be painted with two coats of
lead and a coat of paint.
The CONTRACTOR shall always install the casing according to the project drawings with a
rectilinear profile to guarantee the insertion of the pipeline with no problems.
If during the installation of the casing with the trust boring method unacceptable deviations
from the required route occur, or should it be impossible to insert the pipeline therein, the
CONTRACTOR shall install a new casing with the axis parallel to the required route. The
CONTRACTOR shall however plug the abandoned casing according to the instructions
given by the Representative.
In the front head of the casing the CONTRACTOR shall install a sharp metal projection of
sufficient thickness to reduce damages to the paint as to the external coating due to the
action of skin. That projection shall possibly rise about 1 cm above the coated surface. The
CONTRACTOR shall let the casing come out for about 2 m on the other side of the crossing
so that he can cut out the damaged section, if any. Should it not be necessary to cut it out,
the CONTRACTOR shall coat it adequately.
Since the casing pipe may be internally damaged by the auger during boring, the
CONTRACTOR shall assess the advantage of using the so-called “boring pipe” that is the
front section of the casing which can be cut and used again for other borings.
Cavitations, or sinking of the crossed structure shall not occur during thrust boring. Special
care shall be taken when crossing river beds. The CONTRACTOR shall always have
available on site any equipment and materials necessary for prompt interventions involving
injection of concrete bentonite, etc. The CONTRACTOR shall use those materials to fill up
the hollow spaces and cavities ensuing from the demolition or removal of possible hard and
large elements encountered during boring. The Client's Representative has the right to stop
the works, if the CONTRACTOR does not demonstrate to be adequately equipped to cope
with the above mentioned interventions
The CONTRACTOR shall meet the following provisions concerning railway crossings:
•
•
the thrust pressure shall not be modified when a train is approaching or passes,
he shall be constantly in contact with the person responsible for the concerned
railway section.
In the event of open trench installations, the casing shall be protected against corrosion
throughout its length.
If the line pipes are not inserted in the casing immediately after its installation, the
CONTRACTOR shall close all openings provided in the casing (such as ends, vent and
drain connections etc.), using water tight caps.
The vents placed at both ends of the casing shall allow ventilation. The CONTRACTOR
shall check all the above upon completion of the works, before backfilling the trench.
eni spa
exploration & production division
9.
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 26 of 59
EXCAVATION AND TRENCHING
The normal trenching operation shall be carried out in accordance with the Detail of Trench
for Pipeline.
CONTRACTOR shall prepare and submit to COMPANY a trenching procedure in
accordance with the requirement of the present specification.
Normal excavation, as opposed to rock excavation, is defined as excavation in loose soil, or
rock with weak mechanical characteristic “soft rock”, which can be removed with mechanical
trench excavating equipment such as wheel type ditchers, backhoes, drag-lines, rock
ploughs, rooters, rippers and similar type equipment.
Rock excavation is defined as excavation in material that must be broken up by jackhammer
or by blasting.
At locations where existing underground facilities may be damaged by trenching machinery,
CONTRACTOR is required to carry out manual trenching (without heavy equipment).
In order to maintain stable the trench wall avoiding sliding down of material, the sides of the
trench shall be battered no steeper than the angle of repose of the material. Where
necessary, the sides of the trench shall be stabilised by spraying with water or by other
means.
CONTRACTOR shall provide all necessary shoring and shall take all necessary precautions
to protect the sides of the excavated trench against collapse.
At no time during the progress of the work shall more than two (2) kilometres of open trench
be maintained ahead of other pipeline construction operations.
CONTRACTOR shall e responsible for maintaining the trench in good condition until the
pipe has been lowered-in and the trench has been backfilled. No claim shall be made by
CONTRACTOR against COMPANY by reason of the trench caving in before, during or after
the pipe shall be laid.
CONTRACTOR shall provide at his own expense all necessary shoring to maintain the
trench in good condition. CONTRACTOR shall restore any caved-in section of trench to its
required depth. CONTRACTOR shall provide at his own expense all necessary drainage
ditches and grading of ground adjacent to excavation to prevent water fro running into the
trench. Any water accumulated in the trench that are excavated above water table shall be
removed by pumping to permit the inspection and verification of the trench condition prior to
lowering-in of pipe and to perform all in-situ tie-in welds in the dewatered bell hols.
CONTRACTOR may, at his own expense, move his operations to other dry areas until such
times when work can be performed in any flooded sections of the pipeline.
CONTRACTOR has to prepare procedure for safe trenching tailored for the wet area
encountered to be submitted to COMPANY approval.
CONTRACTOR shall schedule his operations to minimise the time the trench is left open,
this information shall be included in the CEP.
Trenching operations shall not be allowed to interface with natural drainage or with the
operation of drainage ditches, irrigation canals, other water course. Wherever necessary,
pipe or flumes shall be laid across the trench to serve as culverts for water drainage.
CONTRACTOR shall furnish all necessary materials for such purpose.
CONTRACTOR shall excavate and maintain the trench, including all necessary shoring and
support, to allow safe installation of pipe and to prevent damage to the pipe coating.
CONTRACTOR shall immediately repair any such occurrence at his own expense and to
the satisfaction of COMPANY and Authority having Jurisdiction.
eni spa
exploration & production division
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 27 of 59
In normal excavation, the width of the trench bottom shall be 150 mm greater than the
outside diameter of the pipe. The trench width shall be measured at the bottom of the
trench.
At locations where it is necessary to make tie-in welds in the trench, the trench width shall
be increased to provide a working clearance around the pipe of at least 500 mm on each
side of the pipe. The same working clearance shall be provided under the pipe.
CONTRACTOR shall excavate the trench to a depth that will provide the minimum specified
cover over the pipe at all points along the pipeline route, regardless of the contour of the
land and the type of soil or rock encountered. Pipe cover shall be determined by measuring
from the top of the pipe to the average level of graded ground on each side of the trench.
Unless otherwise specified on construction drawings, minimum depth of cover over the pipe
(T.O.P), shall be as indicated in the Project Documentation.
The bottom of the trench shall be uniformly graded and dressed along its length to obtain as
near as possible to a straight line, in order to prevent unnecessary bending of pipe between
sag bends and over bends. The trench bottom shall be specially prepared at sag bends and
over bends to accommodate the bends properly and to provide proper clearance between
the inside bend of the pipe and the bottom or side of the trench.
Irregularities in the dry land trench bottom shall be corrected by backfilling the trench with
clean loosely packed earth or sand to provide a continuous and uniform support for the pipe.
Any rock outcrops, loose rock, hard clods, stumps and other objects which may damage the
pipe or pipe coating shall be removed from the bottom of the trench.
Where the trench is excavated in rock, any rock projecting from the trench walls that may
damage the pipe or pipe coating shall be removed.
Before starting excavation works, a survey must be carried out along the pipeline route, to
locate areas with stagnant water or groundwater near the surface in permeable soils.
Where needed, the area will be surveyed. Possible seasonal excursions must be studied to
plan interventions and choose the most suitable equipment.
9.1
TRENCH IN SPECIAL LOCATIONS
CONTRACTOR shall excavate the trench to greater depths as required at locations such as
the following:
•
•
•
•
•
•
Major Roads crossed by open cut
Water stream
At irregular ground features and land contours, in order to reduce the bending of
pipe and provide the necessary vertical separation.
In areas subject to erosion, such as watercourse banks, gullies, ponds and across
areas with unstable soil when required.
Where necessary, to provide additional cover at over bends.
At other locations as required by COMPANY, or as dictated by other circumstances
and conditions (i.e. where required by governing Authorities or Owners)
On approaches to crossings CONTRACTOR shall begin increasing trench depth at a
sufficient distance from each side of the crossing in order to allow the pipeline to fall
gradually to the lower elevation.
Extra depth of trench performed by CONTRACTOR out of the requirement shall be
considered as normal excavation.
9.2
DRAINAGE OF THE TRENCH
Draining operations shall be carried out without causing any delay to scheduled operations
of pipeline trenching, laying and backfilling.
eni spa
exploration & production division
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 28 of 59
To obtain an accurate draining, suction equipment shall be driven 0.50 m below the trench
bottom elevation.
The use of special equipment for lowering the ground water level and for trench draining
shall be authorized for each single section by COMPANY Representative.
The authorization is usually given when the presence of water requires the trench wall slope
to be less than 50% to avoid any risk of landslide.
Possible buried utilities must be located before driving the suction bits.
Prior to the start of digging operations, the lowering of water to the required level shall be
verified by means of a drill and/or a piezometer.
Draining plants shall be kept working during trench excavation, pipe laying and, if
necessary, the backfilling operations.
The water taken in shall be removed/conveyed and discharged in ditches or existing
watercourses, far from the work area.
9.3
TOPSOIL OR ORGANIC SURFACE MATERIAL CONSERVATION
CONTRACTOR shall remove the topsoil or organic surface material from the areas to be
graded or where excavated material will be placed.
Removal shall be to its actual depth or to a maximum depth of 0.3 metres unless otherwise
instructed by COMPANY. Topsoil or organic surface material shall be removed and piled
separately from excavated material and shall not be used for padding or backfilling the
trench. Upon completion of backfilling and ROW restoration, topsoil or organic surface
material shall be returned to areas from where it was removed, in a condition satisfactory to
the COMPANY.
9.4
SPOIL MATERIAL
It is forbidden to spread the spoil from the excavated trench out of right of way especially in
the wood land or forest area.
Spoil containing rock, or spoil judged by COMPANY as unsuitable for backfill, shall be
hauled away from the ROW and disposed of in such a manner that it cannot be used by
mistake in backfilling the trench.
Only excavated material suitable for use as backfill shall be deposited alongside the trench,
unless otherwise noted.
Spoil banks shall not be permitted to interfere with natural drainage. Proper openings shall
be provided to allow normal drainage of the area concerned.
Where necessary, adequate openings shall be provided in the spoil bank to permit the
passage of vehicles.
9.5
TRENCH PROTECTION
Where necessary, CONTRACTOR shall signalize all open trenches using plastic net,
lanterns, flares, barricades, guard rails and other safety equipment and by adopting all the
appropriate measures to protect CONTRACTOR’s employees, COMPANY’S employees
and any third parties from injury.
Wherever possible, CONTRACTOR shall complete and fill trenched road crossings on the
same day on which they are excavated in order to prevent hazards to night travel. If
circumstances prevent CONTRACTOR from completing the backfill on the same day, he
shall construct a properly marked detour.
eni spa
exploration & production division
10.
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 29 of 59
EXCAVATION BY BLASTING
When blasting works are required in rocky areas, CONTRACTOR shall define in
Construction Plan the method statement with the following indication:
•
•
•
A number of holes are drilled into the rock, which are then filled with explosive.
Detonating the explosive will cause the rock to collapse and thus lengthen the
tunnel.
Repeating these steps will eventually result in a trench.
The positions and depths of the holes (and the amount of explosive each hole receives) will
be determined by a carefully constructed pattern, which, together with the correct timing of
the individual explosions, will guarantee a proper section of the trench.
Drilling equipment shall consist of a hydraulic track drill capable of drilling the required
controlled blasting holes accurately and uniformly across the top of a rock cut, or other
suitable equipment.
Removal shall be carried out in such a manner to minimize disturbance to any surrounding
rock beyond the excavation limits.
All material resulting from the operation shall be managed in accordance with specified
contract requirements.
Drill hole locations shall be indicated by the CONTRACTOR sufficiently in advance of the
drilling so to stake the exact depth from the rock surface to grade elevation at each drill
hole.
Holes deeper than the specified depths may be drilled if approved. Holes shall be drilled to
the same depth below grade except at grade points, where drilling shall be continued
beyond the lower end of the cut on non-level gradients and beyond each end of the cuts on
level gradients in order to provide positive drainage of the shattered layer.
CONTRACTOR shall submit to COMPANY his detailed procedures for approval prior to any
blasting taking place. The procedure shall comply with all good blasting practice and Any
proposed revision in procedure arising during blasting shall be submitted for approval.
Blasting shall only be carried out with the written approval of the COMPANY where possible
mechanical methods of excavation of rock should be used in preference to blasting.
Any landowners or tenants who may be affected shall be notified far enough in advance so
that adequate steps can be taken to protect livestock or other property.
The CONTRACTOR shall comply with the safety procedures of the explosives
manufacturer.
Extreme care shall be exercised to avoid damage to underground structures, cables,
conduits, pipelines and the like, and to underground watercourses or springs. Trial blasts
shall be undertaken to establish the minimum quantity of explosives required. In addition to
shot holes being fully stemmed, blasting mats or other effective means shall be used if
necessary to prevent rock being scattered over the right of way and adjacent property.
The CONTRACTOR shall take every precaution to protect persons and the Permanent
Materials from any injury or damage, which might arise from the use of explosives.
The CONTRACTOR shall be fully responsible for any injury or damage arising from the
blasting operations. Compliance with this specification and approval of procedures by the
Engineer shall not relieve the CONTRACTOR of this obligation.
The CONTRACTOR shall at his own expense, obtain any permits required and shall comply
with the provisions of such permits. See section 3.1.
eni spa
exploration & production division
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 30 of 59
The CONTRACTOR shall carry out blasting procedure in accordance with ASME
A10.7(1987) – (1991Ammendment) Construction and Demolition – Commercial Explosives
and Blasting Agents – Safety requirements for transportation, storage, handling and use.
The information to be provided shall include:
•
•
•
•
•
•
•
•
•
•
Details of all permits and licences, issuing authority and validity period.
The location and length of the proposed area of blasting
The charge pattern
The number of charges
The type of explosive
The sizes of charges
The depths of drill holes
The delays to be used
What notification has been issued
Name of shotfirer
The CONTRACTOR shall submit his blasting programme to the COMPANY at least 5 days
in advance of each 7-day period or as required by the COMPANY.
10.1
BLASTING CRITERIA
As far as the Basting operation is concerned, the CONTRACTOR shall comply with the
following:
•
•
•
•
•
•
•
All shotfiring shall be undertaken by a shotfirer duly appointed by the
CONTRACTOR in writing. Only workmen thoroughly experienced in handling
explosives shall be permitted to supervise, handle, haul, load and fire explosives.
The shotfirer shall supervise the transportation and storage of all explosives.
Explosives shall be carried and stored in approved containers. Detonators shall be
carried in a separate vehicle from that of explosives and shall be stored separately
on Site.
Before shotfiring commences the shotfirer shall give clear and adequate warning to
all persons within, near or approaching the danger zone. In addition, audible
warnings shall be given as follows: One note on a siren 5 minutes before blasting.
Two notes on a siren 2 minutes before blasting. Continuous note or three notes to
indicate the all clear. Visible displays or notices shall be posted on the perimeter of
the danger zone indicating clearly the sequence of audible warnings.
The CONTRACTOR shall be responsible for ensuring that all persons within, near
or approaching the danger zone remove themselves to a safe place.
The shotfirer shall post sentries and, where necessary, suitable notices, on the
perimeter of the danger zone. On completion of blasting the shotfirer shall examine
the area for misfires and if it is safe, shall signal the ‘all clear”.
All shotfiring activity shall be suspended in the event of a thunderstorm.
In the event of a miss-fire, the shotfirer shall duly inform all the sentries and instruct them to
warn all persons likely to approach the shot hole.
The shotfirer shall not approach the hole until he has disconnected the shotfiring cable from
the exploder and not before 5 minutes have elapsed from the last attempt to fire the shot.
The shotfirer shall then examine the cable and connections and remedy any fault found. He
shall then re-connect and make a further attempt to fire the shot if this is practicable.
All persons within the danger zone shall remain under cover until a miss-fire has been
cleared.
In the event of a further mis-fire, the shotfirer shall take steps to ensure that no person
enters the danger zone until the hole has been inspected.
Any unexploded charges shall be detonated by placing and priming an adjacent charge.
Following blasting, the shotfirer shall search the debris for unexploded charges after the
clearance of the miss-fires.
eni spa
exploration & production division
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 31 of 59
The shotfirer shall accurately record all miss-fires in a report to be presented by the
CONTRACTOR to the COMPANY.
CONTRACTOR shall provide the necessary equipment to monitor ground vibrations as
required by COMPANY.
CONTRACTOR shall prepare suitable graphs and tables, according to an accepted method,
so that safe charging loads may be determined in advance.
The proposed blasting pattern shall be fired on an individual short delay electric detonator
using a system, such as Magnadet, that minimises current leakage. Detonating cord shall
not be used outside holes and any used within drill holes shall be kept to the absolute
minimum that is necessary for safety. Good stemming material shall be used in all holes.
eni spa
exploration & production division
11.
11.1
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 32 of 59
PIPELINE INSULATION
GENERAL
The pipeline, line valves, prefabricated bends and
other fittings shall be completely
insulated from the environment. Therefore any bare sections, even if very short, shall be
cleaned and coated by the CONTRACTOR according to the provisions set forth in the
specification included in the contract documents.
When bare pipes are supplied, the CONTRACTOR shall coat them on site according to the
provisions set forth in the relevant specification attached to the contract documents.
Any bare valves, fittings and other special pieces to be buried, shall be adequately coated.
If the pipes and special fittings have already been coated at the workshop, the
CONTRACTOR shall provide to coat the field joints and repair the damaged coating, if any.
The CONTRACTOR's personnel charged with the coating operation shall be skilled and
declared qualified by the Representative.
11.2
ENVIRONMENTAL CONDITIONS
The CONTRACTOR shall not carry out any coating, repair or touch-up operation in the
event of bad weather conditions such as rain, humidity (such as to cause condensation) or
ambient temperature below and anyhow in the event of wet pipes.
The CONTRACTOR can deviate from these provisions, provided that the following condition
are met:
• the surfaces to be coated are throughly dried with adequate heating equipment
without causing damages to the existing coating.
• the surfaces to be coated are preheated to the temperature required by the type of
coating to apply or to at least +10 °C, when the ambient temperature is below +5°C
Should a coating, a repair or a touch-up be performed on the pipeline already laid in the
trench, this trench shall be large enough to allow an easy and perfect execution of the
above mentioned operations.
11.3
PREPARATION OF THE SURFACES TO BE MANUALLY COATED ON SITE
The CONTRACTOR shall free all steel surfaces from any traces of earth, mud, oil or grease
using adequate solvents as per SSPC (Steel Structure Painting Council) Oxides or paint
left over the steel surfaces shall have a finishing grade St. 3 according to svensk Standard
S15 05.5900-1967 (ISO 8501-1).
When small surfaces need to be cleaned, they can be cleaned manually using abrasive
canvas, brushes or scrapers according to SSPC SP2. In this case, the cleaned surfaces
shall have a finishing grade St. 2 according to SIS 05.5900.
Should these surfaces be highly oxidized and should it be impossible to achieve an
acceptable finishing by the manual brushing, the CONTRACTOR shall use a deoxidizer
adequately diluted with clean fresh water according to the supplier’s recommendations.
After applying the deoxidizer with a brush or canvas, the CONTRACTOR shall wait at least
24 hours before brushing the treated surface. Immediately before applying the coating, the
CONTRACTOR shall dust the surfaces thoroughly using adequate equipment and dry not
polluted compressed air.
Before applying any coating, the CONTRACTOR shall check the surfaces carefully to make
sure that there are no defects, burrs, corrosions and similar.
The CONTRACTOR shall remove small defects while larger or deeper defects shall be
removed by cutting out the concerned pipe section.
If the CONTRACTOR has to strengthen the existing coating, he shall first remove any
polluting matters from the sun protection, if any, and the possible stones which might have
got stuck, then he shall make the necessary repairs and perform the required checks.
eni spa
exploration & production division
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 33 of 59
Unless otherwise indicated in the contract documents, the CONTRACTOR shall strengthen
the plastic tapes for the coating of field joints, or following the instructions of the
Representative.
11.4
REMOVAL OF THE EXISTING COATING
The CONTRACTOR shall remove the coating to clear metal using adequate equipment
which does not cause damages to the steel surface. The binding layers (say primer) of the
existing coating or temporary protection shall be removed completely using solvents or
brushes, whenever they are neither compatible with the type of coating to be applied, not
adhesive. If solvents are used, the steel surface shall be thoroughly washed with water.
11.5
PREPARATION OF THE AREA TO BE OVERLAPPED BY OTHER COATINGS
Before applying a coating over an existing one, the CONTRACTOR shall clean the
concerned area removing any foreign matters or deposit and the sun protection.
Before applying the new coating, the CONTRACTOR shall check the adhesion at the edge
of the existing coating and shall remove any coat which does not meet the requirements.
When the existing coating thicker than 2 mm the CONTRACTOR shall chamfer the edges
for a width of about 3 cm.
If the existing coating consists of synthetic resins, the edges shall be chamfered with a
grinding wheel or a brush. The chamfering of bituminous coating shall be performed using a
mild flame and a spatula, avoiding to cause fire or runs.
When the chamfering is completed, the CONTRACTOR shall clean the steel surface and
apply the new coating.
11.6
INSULATION OF BARE SURFACES
As for the required coating cycle, the materials to be used for the insulation of field joints,
field bends, valves, fittings and accessory piping, the CONTRACTOR shall comply with the
relevant specifications. The primer and the coating shall be applied on the steel surface and
on the chamfer for a strip at least 5 cm wide. The CONTRACTOR shall apply the coating
on the uncoated elements immediately before laying or lowering in the trench. In particular,
when the ambient temperature is 30°C or higher, the coating shall be applied within 24
hours, while in the event of lower temperature the coating can be applied within 48 hours
before laying.
11.7
REPAIRS OF COATED
The CONTRACTOR shall inspect carefully the shop-coated pipes to single out any damage
occurred during stacking, handling and erection. The damages, if any, shall be repaired
according to the instructions given by the Client Representative.
11.8
CHEEKS TO BE PERFORMED BEFORE LAYING
The CONTRACTOR shall inspect all field coated surfaces, including field bends obtained
from shop-coated pipes according to the relevant specifications. In particular, the following
inspections shall be performed:
•
•
•
detection of defects with holiday detector
Measurement of the thickness
Inspection of the adhesion
The CONTRACTOR shall check the continuity of the electrical insulation of the pipeline
section consisting of shop-coated pipes
eni spa
exploration & production division
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 34 of 59
The test equipment (say holiday detector) shall be adjusted to a voltage of 80% of the value
adopted in the coating plant.
This inspection shall be performed the day before laying so that any repairs or testing of
repaired surfaces do not slow down the laying activities.
The tested pipeline shall be laid and the backfilling shall comply with the specification. In
case of delay, the CONTRACTOR shall carry out a visual inspection before lowering the
pipeline in the trench; if the delay exceeds 5 days, a new inspection with holiday detector
shall be performed on 100% of the surfaces.
Should natural events, such as hailstorm loading etc. occur after the pipeline has been laid
the CONTRACTOR shall perform a visual inspection and an electrical insulation test, if
necessary, before backfilling the trench. Any repairs following the above mentioned
inspections shall be submitted to the electrical insulation inspection.
11.9
ROCKSHIELD PROTECTION
The rockshield protection can consist of polyethylene or polyvinyl chloride sheets or plates
according to the relevant specification. The said sheets or plates shall however be
perforated to allow the electrical protection.
The CONTRACTOR shall wrap manually the rockshield sheets around the pipeline
(cigarette-wrapping) after having checked and repaired the coating. The rockshield sheets
shall be fixed with adhesive tape having fiberglass reinforcement or with metal straps 15 to
25 mm wide or other non-metallic devices of equal efficiency.
The fastening rings shall have a spacing of 50 cm and the adhesive tape shall be
overlapped at the ends or at least 15 cm.
The CONTRACTOR shall overlap the longitudinal edges of the sheets for at least 10 cm
while the adjacent sheets shall be placed as close as possible. The overlapped edge shall
be turned downward and shall be placed at the pipeline side.
11.10
PROTECTION AGAINST ELECTRICAL OVERCURRENTS
The CONTRACTOR shall install a polyethylene sheath to protect the coating from electrical
overcurrents whenever required by the project drawings.
The sheath shall be applied with the utmost care and the pipeline section protected by this
sheath shall be laid on a sandy bed. The sheath shall be applied after having inspected the
existing coating, and after having repaired it, if necessary.
The CONTRACTOR shall use transparent or translucent low-density polyethylene sheets,
with no holes, discontinuity or defects and having an adequate thickness and width, duly
approved by the representative.
If the polyethylene sheet is supplied in reels, the CONTRACTOR shall cut it in sections long
enough to cover the coated pipe circumference (or a multiple of it) plus at least 10 cm. The
sheets cut as above, shall be wrapped onto the pipeline in one or several layers (cigarette –
wrapping) until a total thickness of 2 mm is reached in the first pass.
A second pass shall be also applied and the total thickness shall be at least 4 mm.
The cigarette-wrapping shall be performed by exerting a strong pressure and avoiding that
foreign matters are entrapped between the existing coating and the various layers of the
sheath.
The CONTRACTOR shall wrap the polyethylene sheet so that the edge longitudinal to the
pipe is:
• turned downward
• at the side generating line of the pipe
• fixed onto the inner surface throughout its length with an adhesive tape at least 50
mm wide.
Each adjacent sheet shall be placed as close as possible or slightly overlap (about 1 cm)
the sheet already wrapped.
eni spa
exploration & production division
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 35 of 59
The edges either approached or overlapped shall be fixed and sealed with adhesive tape.
The end of this tape shall be overlapped at least 15 cm. The tape shall also be applied in
the middle of each sheet.
The joints between the sheets wrapped in the second pass shall be staggered from previous
ones as follows:
• About 180° the longitudinal overlapping
• About half the length, the circumferential joints
If the existing coating is fit for the protection against overvoltage, while any field coating
applied on field joints or any other bare surface is not, the CONTRACTOR shall apply a
polyethylene sheath on the field coated sections extended to 10-15 cm on both ends.
Rigid synthetic resin tubes at least 4 mm thick can be used instead of the polyethylene
sheath.
They shall be applied over a reinforced or double coating and shall be in close contact with
it, provided their circumferential joints are welded. If shells are used (i.e. pipes cut
lengthwise), their longitudinal joints shall be welded as well.
eni spa
exploration & production division
12.
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 36 of 59
FIELD JOINT COATING
CONTRACTOR shall submit the field joint coating procedure for COMPANY approval.
After obtaining COMPANY’s approval of the coating procedure specification, including the
proposed test methods and acceptance criteria, CONTRACTOR shall qualify the procedure.
The specialist COMPANY shall carry out procedure qualification test on site. All coating
procedure qualification tests shall be witnessed by COMPANY.
CONTRACTOR shall give COMPANY seven (7) working day notice to enable COMPANY to
witness all procedures and tests. CONTRACTOR shall produce minimum three test
simulated field joints on a factory coated pipe of each diameter and wall thickness. The
factory applied coating shall be removed from each field joint area by suitable tools plus
blast cleaning. Then, a weld bead shall carried out in the centre of the joint to simulate a
typical field joint configuration. CONTRACTOR shall coat the simulated field joint with the
specified coating system, in accordance with the approved field joint coating procedure.
12.1
INSPECTION AND REPAIR OF COATING
CONTRACTOR shall visually inspect all incoming coated pipe, coated bends and
continuous concrete coated pipe. Any areas area damaged on the coated pipe and bend
shall be subjected to holiday detection to assess the full extent of the damage.
12.2
REPAIR OF ANTICORROSION COATINGS
CONTRACTOR shall inspect and repair plant applied pipe coating and pipe bend coating
damage without concrete coating in accordance with coating specification. Prior to lowering
pipe into the trench, CONTRACTOR shall perform the visually and electrically inspection of
100% the surface of pipeline (field joints, pipes, bends, etc.) coating by an holiday detector
in accordance with the above specification; then, CONTRACTOR shall repair all defects due
to mechanical damage and all defects identified by the holiday detector. All coating repairs
and all recoating shall be re-inspected both visually and electrically after the repaired
coating ha attained its proper cure. Repaired and recoated areas shall be 100 percent
holiday free. Coating repairs shall not be applied to a surface that has a temperature outside
of the minimum and maximum temperatures recommended by the manufacturer of the
coating repair materials.
CONTRACTOR shall submit repair procedure for pinholes and larger defects in the pipeline
coating to COMPANY for approval and the procedure shall be qualified in advance of field
coating work to the satisfaction of the COMPANY.
eni spa
exploration & production division
13.
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 37 of 59
LOWERING IN
No pipe shall be lowered into the trench until the trench has been inspected, prepared and
approved for receiving the pipe.
Lowering-in operations shall not be carried out except in the presence of COMPANY. If such
work is carried out in COMPANY’S absence, CONTRACTOR may be required to lift the
pipeline out of the trench so that COMPANY can inspect the condition of the trench under it.
COMPANY shall have the right to stop the lowering-in operation if, in its opinion, the
lowering-in method is causing damage to the pipe coating.
All lifting equipment shall be subject to safety checks in accordance with the safety checklist
established by CONTRACTOR and regulatory requirements. skilled personnel shall perform
and report the required lifting equipment safety check. CONTRACTOR shall notify
COMPANY of the date of installation of pipe strings a minimum of 48 hours in advance.
Prior to lifting of the pipeline all personnel shall vacate the trench, leave the area between
the pipe string and the trench and the area between the lifting equipment and the pipe
string.
All as build requirements, in accordance with the Contract, shall be carried out during the
installation.
Wide nylon lowering in belts of sufficient width and safe working loads (with certificate
lifting), shall be use for lowering; is strictly prohibited use during the lay pipe any type of
roller cradle.
Immediately prior the lowering-in the entire length of section shall be holiday tested in the
presence of COMPANY inspectors and any necessary repair carried out to COMPANY’s
satisfaction.
The pipe shall be lowered into the trench gradually and uniformly. The side-boom tractors
shall be of sufficient number and capacity, and shall be placed at close enough intervals to
prevent sagging, sliding, overturning or buckling of the pipe. The pipe shall not be dragged,
dropped or subjected to any jarring or impact.
When the line is lowered in place, it shall conform to the trench bottom without requiring any
external force to hold it in place. The trench bottom shall be properly graded to support the
pipe along its entire length. Any voids under the pipe shall be carefully filled with loose,
clean soft earth or sand.
When lowering long sections of pipe, the side-boom tractors shall leapfrog along the trench
line leaving enough equipment holding the pipe to prevent it from sliding against the trench
wall, overturning or buckling.
Extra care shall be taken to ensure that the pipe coating is not damaged when removing the
lowering-in slings from the pipe. CONTRACTOR shall excavate around the slings if
necessary to clear them and to prevent them dragging excessively against the coating after
the pipe has been lowered-in.
The coating of lowered-in pipe shall be closely inspected for damage resulting from the
lowering-in operation. In the event of such damage, or if the pipe coating is damaged after
the pipe has been lowered-in, the pipe shall be raised from the trench and all damaged
coating repaired.
Sections of pipe shall not be dragged or pulled into position for tie-in into the line. The length
of pipe sections shall be adjusted to allow tie-in operations to be effected without resorting
to dragging or pulling.
The pipe sections shall be lowered in such a manner that the pipe bends will fit the
corresponding bends in the trench.
Lowered sections of pipe, if not to be immediately tied-in, shall be “crotched” off the trench
bottom with padded skids, and the open ends secured with water tight night caps to prevent
the entrance of sand, water or animals. The caps shall not be removed until the pipe is
ready to be tied-in.
Where the flotation method is used, the pipe shall be floated into position fitted with
adequate flotation tanks or pontoons, as necessary. Care shall be taken to guide the pipe
through the trench and prevent the pipe from rubbing against the wall of the trench.
Whichever method is used for lowering or sinking the pipe into the trench, it shall be
performed in such a manner that the concrete weight coating is not over stressed or cracked
eni spa
exploration & production division
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 38 of 59
due to excessive deflection or in any other way damaged. The pipe shall lie naturally and be
continuously supported along its entire length in the bottom of the trench.
CONTRACTOR shall use a sufficient number of flotation tanks or pontoons and take all
other precautions necessary to eliminate stresses in the suspended pipe and not exceed the
specified minimum bending radius limitations.
After the pipe is in position, the flotation tanks shall be removed in such a manner as not to
damage the coating. If necessary the pipe shall be filled with filtered inhibited water.
Close observation of the pipe sinking shall be maintained to ensure that the pipe is in the
trench and that the line is filled completely.
If CONTRACTOR elects to use the push/pull method, he shall submit to COMPANY fully
detailed procedures including a detailed list of equipment and maximum pull force he
proposes to use. COMPANY shall be informed of CONTRACTOR'S intent to commence
pipeline lowering-in.
13.1
ABOVE GROUND PIPELINE
Any pipeline sections resting on above ground sections, bridges or tunnels are defined as
above ground pipelines. Before laying the pipeline shall have been painted, galvanized or
coated according to the provisions set forth in the project specifications.
The CONTRACTOR shall assemble the supports either they be on bridges, in tunnels or
elsewhere, in compliance with the planimetric and altimetric alignment and with the distance
indicated in the drawings. The rollers must be adequately lubricated and checked for their
smoothness and electrical insulation. In the event of seizure, the CONTRACTOR shall
repair or replace the defective rollers. The rollers shall be aligned before connecting the
overhead section with the ends of the buried sect ions.
In the event of overhead sections where the descends are obliquely, the final alignment of
the end supports shall be made just before welding.
The CONTRACTOR shall lay the overhead section without submitting it to unallowable
stresses or causing plastic deformations. Tie-in welds shall be performed when the ambient
temperature ranges between and 30" and when the pipeline has been buried or a section of
150 m minimum on each side for at least 24 hours.
The laying bed adjacent to the overhead sections shall consist of a saddle or suitably
compacted soil to avoid settlements and therefore stresses on the connecting branches.
Adjustments, if any, shall be performed by modifying the final section of the buried pipeline,
avoiding stresses and deformations on the overhead section.
Before backfilling the final section of the connecting branches equipped with bends, the
CONTRACTOR shall check that the loads on the shoulders at the ends comply with the
design requirements.
If the pipeline is not assembled in place (i.e. when pipes are welded at tunnel inlets or at the
head of bridges) and is laid on rollers, the CONTRACTOR shall install the welded string by
pulling it and possibly pushing it in the very initial pulling phase.
In the event of bridges, it is necessary to make sure that the stress ensuing from the pulling
force can be supported by the piers.
The stress shall stop immediately after the initial pulling phase.
The CONTRACTOR shall adjust the speed of travel of the pulled pipeline to avoid harmful
impacts on the rollers.
It is recommended to apply a cone-shaped head on the pipeline front end to facilitate the
sliding on rollers.
Before commencing the works the CONTRACTOR shall give the Representative a detailed
and complete report on the pipeline installation procedures. That report shall cover:
•
•
•
•
•
•
head hooking system
description of the pulling winch
winch anchoring system
characteristics of the pulling cable
braking device, if any
pulling modalities ( i.e. pulling force, speed) and related calculations
eni spa
exploration & production division
•
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 39 of 59
modalities of erection and connection to the buried pipeline
The coating of buried pipes shall be applied also to the overhead section for a height of
about 30 cm from the ground level.
The CONTRACTOR shall seal the ends of the reinforced coating by means of a heat
shrinkable sleeve.
If the pipelines are insulated and protected with an external metal sheed jacket, this jacket
shall be extended to at least 50 cm below the ground level.
The CONTRACTOR shall check the 100% of the joints in the overhead section according to
the provisions set forth in the welding specification. During the hydraulic test of overhead
sections, the CONTRACTOR shall keep the temperature of the pipe above the freezing
point, constant by means of glass wool mattresses or similar.
eni spa
exploration & production division
14.
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 40 of 59
BEDDING – PADDING AND BACKFILLING
The following definitions are given:
Bedding:
The screened material for bedding shall not contain gravel larger than 5x5 mm nor any
sharp objects, foreign material or vegetation.
Padding:
the material used for sand padding shall be screened and of the same gradation as that
used for bedding and shall be free from stones, rocks, foreign material and vegetation.
Immediately following lowering in of pipeline, sand or other material padding shall
commence, at first sufficient quantity of padding sand to surround of pipe shall be placed.
CONTRACTOR demonstrate that the lowered section can be completely sand padded as
one continuous operation.
Backfilling:
the trench shall not backfilled until the COMPANY have approved the sand padding around
and above the pipeline. Prior to commencing initial backfilling the fibre optic cable shall be
laid and sand padded and the warning tape placed all in accordance with specification.
No trench shall be backfilled before COMPANY has inspected and approved the position of
the pipe in the trench, its fit to the trench and its depth. Should any backfilling be performed
without the prior approval or presence of COMPANY, CONTRACTOR may be required to
uncover that section for inspection at his own expense.
The backfilling operation shall follow the lowering-in operation as closely as possible, in
order that the pipe may be anchored to the ground and to avoid exposing the pipe coating to
excessive temperatures or inclement weather. Backfilling shall be completed prior to any
hydrostatic testing.
Backfilling of all side bends, over bends and sag bends shall be performed immediately after
lowering. In no case shall backfilling of bends be performed later than the evening of the day
in which the bends are lowered into the trench. Pipe bends shall be covered for a distance
of at least 4 m to each side of the centre of the bend.
Any backfilling omitted for the installation of pipeline appurtenances, cathodic protection test
leads, tie-in welds, etc. shall be performed immediately after such installations have been
completed and approved.
Backfilling the trench shall be executed with extreme care in order not to damage pipe or
pipe coating. Wherever deemed necessary by COMPANY, the initial layers of backfill shall
be deposited by hand.
Under no circumstances shall foreign material such as ash, decayable material, construction
refuse, site waste, oil or oil-soaked dirt, or other foreign materials be placed in the trench or
allowed to become mixed with acceptable backfill material.
No containers, cans, drums timber, skids, rope brush, welding rod or other debris, waste or
refuse shall be placed in the trench. All such material shall be removed from the right of way
on a daily basis and disposed of in a manner acceptable to COMPANY.
14.1
BACKFILL MATERIALS
In general, the trench shall be backfilled using the same materials excavated from the
trench, except in the case where such materials are judged by COMPANY as being
unsuitable, and shall be subjected to the requirements specified below.
The initial layers of backfill material around and on top of the pipe shall be formed using
suitable backfill material only. Suitable backfill material is defined as fine, loose, soft earth or
sand free of sharp gravel, rock, hard clods of earth, hard objects, vegetation, organic
eni spa
exploration & production division
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 41 of 59
materials or any other detrimental matter or foreign objects that could damage the pipe or
coating.
Suitable backfill material shall be prepared on site from the excavated spoil, including by
screening if necessary. Where there is insufficient loose earth from the trench spoil to
provide suitable backfill material, CONTRACTOR shall obtain, load, haul and place
acceptable backfill material at no additional cost to COMPANY.
Suitable backfill material shall be piled to a depth over the crown of the pipe such that
ensures an annular layer of this material all around the pipe as per Standard drawing. The
remainder of the trench shall be backfilled with excavated material according to the
Standard drawing.
14.2
BACKFILL IN ROCKY AREA
Where the trench is excavated in rock, CONTRACTOR shall obtain suitable backfill
material, as defined above, from pre-approved sources. The backfill material shall be used
for padding the bottom of the trench and for the initial layers of backfill around the pipe, as
specified above. CONTRACTOR shall load, haul and place the suitable backfill material at
no additional cost to COMPANY.
The trench bottom padding in suitable backfill material shall be placed to a level of 200 mm
above the highest rock outcrop in the bottom of the trench.
Where no suitable backfill material is available, “Rockshield” or an approved equivalent may
be used to protect the pipeline. The protection method shall be subjected to COMPANY’s
approval.
The remainder of the trench shall be backfilled with material free of any rocks, as per the
Standard drawing.
CONTRACTOR shall dispose of all surplus rock removed from the trench in a manner
acceptable to COMPANY.
14.3
BACKFILLING AT SPECIAL LOCATIONS
CONTRACTOR shall provide diversion berm on sloping terrain across the right of way as
required to direct the flow of water into the normal irrigation furrow to prevent erosion and
washout of the backfill.
All watercourse banks, sides of drainage ditches, and all open cut ground road crossing
shall be backfilled in 150 mm. Each layer shall be thoroughly compacted by suitable
compacting equipment to provide a good bond between the undisturbed sides of the trench
and the new backfill material. CONTRACTOR shall adequately protect all openings made in
the backfill material against washout and erosion, in a manner satisfactory to COMPANY.
Backfill at special locations shall be maintained by CONTRACTOR until the entire activity
has been completed and accepted. No extra cost will be incurred by COMPANY for work
arising out of repairing backfill damaged by flood, washouts, slides, setting or other
conditions. CONTRACTOR shall be liable for all damages to third party facilities during
construction activities.
14.4
BACKFILLING PROCEDURES
The trench may be backfilled by means of angle dozers, front-end loaders, backfilling
machines or other suitable equipment approved by COMPANY.
Backfilling shall be done in such a manner as to ensure that the space below and up the
sides of the pipe are filled with suitable backfill material, as specified above, up to the
required level above the crown of the pipe. The remaining backfill shall be accomplished in
eni spa
exploration & production division
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 42 of 59
a manner that will not disturb the initial layers of backfill material placed around and over the
pipe.
When the trench has been filled up to the specified level above the crown of the pipe with
suitable material, the backfill shall be compacted using an acceptable method, approved by
COMPANY, which will ensure compaction of the backfill material without deflecting or
flattening the pipe. The remainder of the trench backfill shall also be compacted.
In certain areas, COMPANY may require that compaction of backfill is carried out using
hand operated machinery or water packing.
After the backfill has been satisfactorily compacted, all remaining excavated material shall
be heaped over the centre of the trench and feathered out to ground level for a distance of
500 mm to 600 mm beyond each side of the trench. On the centreline of the trench, the
backfill shall be built up to a height above the adjoining ground level of not less than 200
mm and not more than 400 mm, except at special locations requiring flat finished ground.
No excavated material shall be left on the ROW.
eni spa
exploration & production division
15.
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 43 of 59
PARALLELISM WITH EXISTING PIPELINE AND CROSSING OF INFRASTRUCTURES
Where the new pipeline is planned to run in parallel to the existing pipeline, the position of
the buried existing pipeline shall be identified by pipe detection procedure and the found
location shall be properly indicated in the ground by markers; CONTRACTOR shall
restrictedly follows the relevant requirements for the protection of the pipe.
A 10 m wide exclusion zone, centred on the existing pipeline route located shall be
established by CONTRACTOR.
Inside the exclusion zone CONTRACTOR is not allowed to perform excavations. Moreover
transit with heavy equipment shall be via properly constructed and signed access assuring
the fully protection of the underground services.
The exclusion zone shall be temporary fenced by CONTRACTOR during Construction
Works.
No protective measures including concrete slab protection should be installed over or near
to the crossed pipeline without the prior permission of COMPANY. Material, the dimensions
and method of installation of the proposed protective measure shall be submitted for
COMPANY approval. The method of installation should be confirmed through the
submission of a method statement.
CONTRACTOR may dig, with a mechanical excavator no closer than 5 metres (outside the
marked exclusion zone) from the located pipeline.
Should hand excavation inside the exclusion zone be requested, it shall be carried out with
hand held power tools and no closer than 1.5 m; where sufficient depth of cover exists,
following evidence from hand dug trial holes, light tracked vehicles may be permitted to strip
topsoil to a depth of 250 mm, using a toothless bucket.
No topsoil or other materials should be stored within the easement without the written
permission of Owner and/or COMPANY.
No topsoil or materials shall be stored over the pipeline, deviation from this requirement has
to be minimized and if necessary CONTRACTOR shall define the work in a proper
procedure inclusive of special precaution, submitted to COMPANY approval.
Mechanical excavators shall not be sited or moved above the pipeline unless written
authority has been given by the COMPANY responsible person.
Mechanical excavators shall not dig on one side of the pipeline with the cab of the excavator
positioned on the other side.
No fires shall be allowed in the easement strip or close to above ground installations.
Where work is being carried out parallel to existing pipeline easement a post and wire fence
should be erected as a protective barrier between the works and the pipeline.
Traffic and tracked equipment crossing of existing pipeline will, in general, be restricted.
Where crossing of the pipeline is absolutely essential, specific crossing points shall be
designated by CONTRACTOR and submitted to COMPANY approval. These crossing
points shall be specifically designed and constructed as temporary access roads, to provide
the necessary protection to the existing pipeline, taking into account load distribution. Under
no circumstances must heavy wheeled goods vehicles be allowed to cross the existing
pipeline without additional protection.
A calculation exercise should also be undertaken by CONTRACTOR, to determine the
effect of depositing excavated spoil from the pipeline, directly over the existing pipeline. It
may also be prudent in some particularly sensitive areas, to consider forming barriers from
the excavated spoil, prohibiting pipeline traffic from approaching the existing pipeline trench.
eni spa
exploration & production division
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 44 of 59
Compliance with the requirements listed below does not in any way release CONTRACTOR
from all or any of his responsibilities, guarantees or contractual obligations.
15.1
MAJOR WATERCOURSE CROSSING
Major watercourse crossings shall be realised according to that provided for in the detail
design.
Prior to starting the works, CONTRACTOR shall nevertheless carry out the appropriate
investigations in order to define the construction criteria and the period in which to carry out
the works.
The results of the investigations, the construction criteria, the plant chosen for the works and
the detailed programme of works shall be included CEP. In the case of crossings of lengths
requiring the adoption of special pipe laying methods, in addition to specifying the type and
quantity of plant required, its positioning and the laying methods, the report must also
include the following:
•
•
•
•
Buoyancy study
Calculation of the stability of the current (if any) and the characteristics of possible
transverse anchoring systems for the pipe during laying.
Dimensioning of mechanic protection of the pipeline to be assured by continuous
concrete overweighting applied for the major ouadis that require.
Calculation of stresses on the pipeline.
Moreover CONTRACTOR shall consider the following:
•
•
•
•
•
15.2
Pipe strings at major watercourse crossing shall be pre-tested prior to installation
and CONTRACTOR shall repair leaks (if any) at his own expense.
The pipeline for crossing shall be designed by CONTRACTOR and submitted to
COMPANY approval, CONTRACTOR shall demonstrate that the scouring
clearance and banks reinstatement is sufficient to assure the stability and efficiency
of the pipeline.
The minimum radius of curvature and elastic bending requirements must be
respected in order to prevent excessive cracking and crushing of the concrete over
weight coating.
After the pipeline has been laid, CONTRACTOR shall check its position and verify
that it is continuously laid on the bottom of the excavation.
Any discontinuity in the support along the pipeline is inadmissible and must be
rectified in a manner acceptable to COMPANY.
MINOR WATERCOURSE CROSSING
The crossing ground profile after reinstatement, shall not modify the existing hydraulic
characteristics of the watercourse. Consequently, where necessary, temporary works shall
be employed to control the water flow.
Material excavated from the banks or from the R.O.W earthworks shall not be stockpiled,
either temporarily or permanently, in a position where it may obstruct the natural flow of the
water.
CONTRACTOR shall reinstate the minor watercourse at completion of the pipe laying
operations.
15.3
WATERCOURSE BANKS SCOURING PROTECTION
The major watercourse that present banks with evident signs of lateral erosion shall be
carefully studied by CONTRACTOR in his CEP; in these cases stone wall protection or
gabions shall be designed as indicated in the detail design drawing relevant the Longitudinal
Scouring Protection.
eni spa
exploration & production division
15.4
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 45 of 59
EROSION PROTECTION
Prior the ROW CONTRACTOR shall evaluate all the area subject to soil erosion, especially
where gullies appears in the close vicinity of the pipeline axis.
This areas have to be carefully studied, and a detail design and construction procedure has
to be presented by CONTRACTOR in his CEP in order to demonstrate that the pipeline can
be installed in a stable and safe position for all its design life.
In particular the ROW profile shall be increased to fit the erosion condition of the area, the
pipeline shall be laid below the bottom level of the surrounding gullies that are present, in
alternative restoration work by gabions or stone wall shall be used.
In the slope where the trench can determine the preferred washing of water erosions, sand
cement bags shall be inserted in the trench.
CONTRACTOR shall reinforce the backfill where the pipe trench cuts through the banks of
watercourse, creeks, streams and ditches. This shall be achieved with sand or earth-filled
sacks, stabilised sand or soil, lean-mix concrete, rock or concrete headwalls, as called for in
the approved construction drawings.
Bags or sacks shall be of the polyurethane woven type or similar, sized to allow earth or
sand fill.
Where the pipeline emerges above ground as shown on project drawings, and at other
locations where the ground/soil conditions indicate possible settlement, special care shall be
taken to ensure that the buried section of pipeline is adequately supported against
settlement.
15.5
MAJOR ROAD CROSSING
Major road crossings shall be realised with the installation of casing pipe according to the
detail design drawing.
The CONTRACTOR shall consider the following:
•
•
•
•
all pipeline welds shall be 100% radio-graphically inspected.
Pipe strings at major road crossing shall be pre-tested prior to installation.
CONTRACTOR shall repair such leaks at his own expense.
The casing shall be installed by thrust boring.
Prior to welding, the casing pipes shall be inspected for ovality or dents, and these defects
must be eliminated by hammering. If the extent of the damage makes this impossible, the
damaged sections must be cut and the weld bevel reinstated, ensuring that the new face is
perpendicular to the centreline of the pipe.
The vent pipes are to be inserted directly and welded to the ends of the casing pipe prior to
inserting the line pipe, according to relevant typical drawings.
Casing end seal shall be installed to the ends of the casing pipe.
Insulating collar spacers shall be installed to the carrier pipe to prevent any contact between
the pipes.
On completion of the works, a check will be performed to ensure that the electrical insulation
between the casing and carrier pipe is intact. If, during the test, it is found that there is
contact between the two pipes, CONTRACTOR shall identify and eliminate the cause, even
if this means withdrawing the carrier pipe from the casing.
When authorised by COMPANY, the road crossing may be carried out in open-cut, though
only in the presence of rocky ground. An open-cut crossing can only be performed after the
length of casing pipe has been previously prepared and is ready to lay. Immediately after
the casing pipe has been laid, the trench must be backfilled up to the upper generatrix of the
casing with loose material in layers of 30 cm compacted to 95% of max dry density
evaluated with Modified Proctor Test, ASTM D 1557-91, 1998. The backfill shall be
completed using suitable inert material, also compacted to 95% of the M.P. value. The road
surface shall be reinstated immediately to allow the passage of road traffic.
Any excess material remaining after backfilling and that cannot be spread on-site shall be
transported to a COMPANY approved site or waste disposal facility.
eni spa
exploration & production division
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 46 of 59
It is CONTRACTOR’S responsibility to maintain any day or night signalling equipment in
perfect working order for the entire duration of the works until the permanent reinstatement
of the road sub-grade. Traffic lights may be used, when necessary, for safety reasons.
15.6
MINOR ROAD CROSSING
Minor road crossings shall be realised in accordance with the project and the drawing
issued by engineering phase. By open-cut method without a casing pipe, the works can
only be carried out after the pipeline has been previously prepared and is ready for laying.
The excavation must nevertheless be executed in line with COMPANY requirements and
according to the project design. Concrete slabs shall be located above the laid pipeline as
indicated in the typical drawing. Minimum cover for the track road crossing shall be 1.5 m
minimum.
The excavation shall be backfilled immediately after the pipe has been laid, following the
same procedure as that reported for main road crossings.
During the works, road traffic may be reduced using an alternating one-way system, subject
to the prior direct approval of COMPANY and the relevant authorities.
Night and day signalling equipment must be kept fully operational for the entire duration of
the works until the permanent reinstatement of the road sub-grade.
15.7
HDD CROSSING
Horizontal directional drilling is a trenchless construction method utilizing equipment and
techniques form horizontal oil well drilling technology and conventional road boring. HDD
construction is to used to install gas - oil pipeline & water pipeline etc. where conventional
open trench construction is not feasible or will cause adverse disturbances to environmental
features, land use or physical obstacles.
HDD technology is used in many situation including the following:
•
•
•
•
•
•
Lake crossing
Wetland crossing
Canal and watercourse crossing
Valley crossing
Sensitive wildlife habitat
Road and railway crossing
The crossing by HDD shall be realised according to detail design and detailed corssing
drawings.
When HDD methodology has to be used, CONTRACTOR shall prepare the procedure for
the crossing and prior to start the works, CONTRACTOR shall carry out the appropriate
investigations in order to define the construction criteria and the period in which to carry out
the works.
Moreover CONTRACTOR shall investigate for the workspace for the drilling supporting the
entry site location requires satisfactory access as well as as stable ground conditions to
support heavy equipments.
Equipments typically found on the entry site of HDD include:
•
•
•
•
•
•
•
•
The rig unit
Power unit and generators
Drill pipe rack and drill pipe
Water dump
Drill mud supply
Drill mud mixing tank
Drill mud pump
Mud handling and cleaning system
eni spa
exploration & production division
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 47 of 59
Since the drill exit site is the location for the fabrication of the pipe stringing as well as, the
pipe string is inserted into the bore hole, the workspace required is typically longer to
accommodate the pipe string and may require extra temporary workspace outside the right
of way (ROW).
Equipment typically found on the exit pipe side of the HDD includes:
•
•
•
•
•
•
Exit mud containment tanks/pits
Cutting settlement tanks/pits
Pipe rack and product pipe
Rollers and pipeline handling equipment
Side booms and other heavy equipment
Pipelines, welding, coating and testing equipment
Before start with the HDD methodology woks CONTRACTOR shall endorse the all the
technical data collected by Engineering phase and the results of the data acquisition, the
construction criteria, the plant chosen for the works and the detailed programme of works
shall be included CEP. In the case of crossings by HDD the report must also include the
following:
Overall pipeline route selection
Crossing location selection
HDD crossing method selection
Availability of access
Siting of entry and exit points
Availability of water source
Pipeline diameter
Project schedule
Watercourse – heavy traffic road – water channel – railway width, depth and flow
Environmental sensitivity and associated constrains
Geotechnical survey data – including laboratory test result
Topographical survey data
Hydrological data
Regulatory requirements and conditions including timing constrains
Equipment availability
Subcontractor (if any) expertise
Downstream water users
Water pollution prevent
Landowners and community issues
Engineering constrains
HDD execution season
No drilling restricted zone
Any excess of material remaining after HDD including Bentonite Mud shall be disposal in
appropriated waste area after COMPANY approved site or disposal facility.
It is CONTRACTOR’s responsibility to fully restore the worked area after the completion of
the drilling activities on both site of the crossed service.
15.8
RAIL WAY CROSSING
The pipeline section crossing the rail way is to be installed in a casing and shall have the
required thickness and must b at least 2 m longer than the casing.
The casing underneath a railway crossing shall extend at least 10 m over the limits of the
crossing. After having completed and successfully inspected the coating and the repairs, if
any, the CONTRACTOR shall apply the collar spacers according to the spacing and
modalities stated in the project drawings. The section to be pulled in shall be perfectly
straight.
The CONTRACTOR shall plug both ends of the casing with rubber plugs or heat shrinkable
band according to the provisions of the project documents.
The coating unevenness, if any, in contact with the plugs, shall be smoothed off.
eni spa
exploration & production division
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 48 of 59
The metal straps used to fix the rubber plugs shall be protected with any liquid cold-applied
insulating material (such as paint, primer, mastic).
The CONTRACTOR shall check that no contact exists between the casing and the pipeline
by means of electrical measurements that shall be the subject of a report.
The first measurement shall be performed with the pipeline pulled in the casing but not yet
tied-in. When taking the measurement, the pipeline shall not touch the water, the noninsulated supports or the casing.
The measurement shall be performed by connecting the pipeline and the casing (or a vent)
by means of insulated conductors to the terminals of a generator with no-load output voltage
ranging between 12 and 25 volts.
The conductor to be connected to the pipeline which in turn is connected to the negative
pole of the generator, shall be soldered, while the conductor to be connected to the positive
pole shall be fixed to the casing with a connecting terminal in a point with no insulation.
Once the connections have been made and their efficiency checked, the output voltage
shall measured by an ammeter having a full scale of 100.
If the needle of the instruments is steady on zero or moves slightly, the insulation between
the steel structures is acceptable. Should a contact be revealed (the needle is pointing to
the full scale) or should water, foreign matters or coating defects be present (the middle is
pointing to a mean value), the CONTRACTOR shall single out and eliminate the cases of
insufficient insulation even if in that case the pipeline needs to be pulled out.
The second measurement shall be taken upon backfilling of the pipeline already tied-in and
when all fittings have been installed on the casing.
The measurement procedure is the same as per the previous one.
If the needle is pointing to mean scale values, the intervention of qualified personnel expert
in cathodic protection is required as they are the only ones capable of evaluating through
adequate and complex measurements, if it is acceptable or if correction works need to be
performed. Any contacts shall be eliminated by the CONTRACTOR.
The Client's Representative however reserves the right to accept it or not.
The CONTRACTOR, to assure that the insulation between the pipeline and the casing is
maintained, shall check that:
• at the casing outlet, the pipeline is laid, for at least 10 m in length, on well
compacted soil sand bags to avoid further settlement
• backfilling is performed correctly.
15.9
TRENCHLESS CASING INSTALLATION FOR CROSSING
Where required, in case is not possible to interrupt by trenching the road lane the casing
shall be installed by trench less method (drilling of thrust boring). Prior to commencement of
any drilling CONTRACTOR shall submit to COMPANY complete details of the proposed
construction method for approval. To install the casing pipe with the boring machine, pits are
required at both sides of the crossing. The dimensions of the pits shall be determined taking
into account the space required for setting out the boring equipment and laying of the
pipeline to the specified profile.
The pit sides shall be suitably sloped to prevent cave-in or landslides. To this purpose it may
be necessary, especially when the water table is present in the trench, to install sheet piling
against the pit walls suitably sized to resist the earth thrust.
Thrust boring shall be performed at an adequate depth below the crown of the road or
Railway and in accordance with project drawings.
In case high ground water table is present, and risk of soil siphoning or caving could occur
at surface, jacking installation by drilling head with earth pressure balancing control and
muck removal by slurry circulation, can be proposed by CONTRACTOR for steel casing
pipe installation.
CONTRACTOR method statement shall demonstrate the safe and effective plan of work
execution, the method statement shall be in compliance with requirement of relevant
Authorities and of crossing owner and submitted to COMPANY approval. CONTRACTIOR
shall be the sole responsible of the good performance of the work.
eni spa
exploration & production division
15.10
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 49 of 59
PIPELINE AND UNDERGROUND CROSSING
When existing pipeline has to be crossed, CONTRACTOR shall prepare the procedure for
the crossing under the service unless particular condition dictates otherwise.
The minimum vertical or horizontal clearance between the pipeline and any underground
facility shall allow the easy installation the new pipeline and the existing pipeline or other
facility.
Typical for Buried Pipeline Crossing; concrete slab between the pipeline shall be installed as
mechanical protection.
The angle at which a foreign pipeline is crossed shall not be less than 45 degrees unless
approved by COMPANY.
No machine excavation shall be performed closer than 2 m from the exposed location of an
underground facility. The remainder of the excavation on each side of the underground
facility shall be carried out by hand-digging unless COMPANY authorises the use of hand
held power tools.
CONTRACTOR shall adequately support the exposed facility at all stages of construction. If
necessary, CONTRACTOR shall support both the new pipeline and the existing pipeline in
an approved and permanent manner to prevent any future settlement.
Damage to an exposed existing pipeline shall be avoided through the use of protective
timber cladding. Work shall be planned and executed so that the existing pipeline is not left
exposed overnight.
CONTRACTOR shall carry out interaction tests between the pipeline and an existing
pipeline to determine whether the new cathodic protection system for the pipeline will have
any adverse effects on the existing pipeline or vice versa.
CONTRACTOR shall take remedial measures as necessary to keep the two cathodic
protection systems compatible.
At every crossing of a foreign pipeline, CONTRACTOR shall install cathodic protection test
leads and bonding leads on the pipeline for bonding to the foreign pipeline. The required
test leads and bonding leads on the foreign pipelines shall be installed by CONTRACTOR
as instructed by COMPANY.
Backfilling around the new and existing pipeline shall be carried out in such manner as not
to cause damage to the new or existing pipeline. The backfill shall be rammed and
consolidated as specified by owner of the utility to his entire satisfaction. Any coating
damage on the existing pipeline shall be repaired to the satisfaction of the owner before
backfilling. Backfilling shall not increase or decrease the original cover over the existing
pipeline.
15.11
CROSSING OVERHEAD POWER LINE
Contact with overhead electric lines can be lethal whether they are carrying voltage as high
as 400 kV or as low as 240 V. Overhead power lines are not normally insulated and if direct
contact or near contact is made with them i.e. by a crane boom, scaffold pole or similar
conductive material the electrical current will arc to earth across any person or persons in
the immediate vicinity causing serious injury. Power lines may automatically switch off
resulting in claims for loss of revenue from the utility owner.
Each piece of equipment utilized to handle pipe in any way, such as unloading picking up,
transporting, bending or “lowering in” shall be grounded and may be equipped with a cable
assembly capable of grounding the joints of pipe to the piece of equipment handling that
pipe.
Protective barriers shall be fixed 6 meters (minimum) parallel from the nearest overhead
transmission line. To avoid any equipment coming near the overhead high voltage
transmission lines one of the following will be temporarily erected.
• Non-conductive rope with “Bunting” or coloured flags or;
• Any means of barricading the area as approved by the owner
At either side of the passageway or near the goal post, a warning notices with the following
information shall be fixed or installed.
• Clearance height
• Voltage of the overhead transmission line
• Advice to drivers/operators to lower their jibs or keep the jibs below this height.
eni spa
exploration & production division
15.12
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 50 of 59
PIPELINE CROSSING ROCKY STEEPED AREAS
CONTRACTOR shall identify these areas in well in advance the Construction phase, and
will propose method statements suitable for each of them with the criteria here below
mentioned. Also proper welding procedure shall be prepared if necessary.
When ROW slope exceed 15%-20%, depending on slope section length, the same can not
be used for wheeled vehicles, either for personnel, material and pipes transportation. In this
case CONTRACTOR shall design and prepare temporary by-pass roads to assure
accessibility to all working sites.
As a consequence pipes will not be directly strung along the ROW so that they shall be
stockpiled in downhill area
ROW width can be reduced to suit construction requirements only.
CONTRACTOR shall arrange the ROW and trenching activities considering the soil and
slope of the section. The soil condition leads the selection of equipment either for ROW
preparation or trenching phase.
In case of normal soil (i.e. clay and sand) and low gradient (15%-20%), dozer will be used
for the clearing of slope section, starting from up-hill to down-hill point.
Trenching will be performed by crawler backhoe.
On moderate slopes backhoe may work moving on the pipeline centre line. Else, backhoe
will excavate from trench side eventually on levelled spots.
Pipes may be either strung outside of the trench for subsequent line welding and lowering-in
of the completed column or into position directly into the trench. The first option is
practicable upon verification, by calculation, of the stability of the pipeline section
consideration being given to slope gradient, section length, pipe size and weight.
Pipe string can be secured against accidental shifting by means of adequate restraints
(pegs, wedges, etc.).
When bringing pipes directly into the trench, the operation is carried out concurrently with
welding, each pipe being set into position once the preceding pipe has been welded. If
pipeline section is welded outside of the trench and subsequently lowering-in, precautions
must be taken in order to prevent risky movements.
CONTRACTOR shall consider different means to control and retain the string. Whereas the
section is welded directly inside the trench, backfilling shall closely follow welding, NDT and
coating activities.
Sand bags slope breakers shall be erected concurrently. While sand bags slope breakers
prevent backfilling wash-out, surface erosion and/or landslip must be as well avoided. This
is achieved by means of draining ditches and mattresses across the ROW
eni spa
exploration & production division
16
TIE-IN
16.1
PIPE STRING TIE-IN
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 51 of 59
CONTRACTOR shall perform all work necessary to tie-in separate welded pipeline sections,
into a continuous system.
CONTRACTOR shall bevel, align and weld the pipe in accordance with the requirements of
welding specifications.
Welding after the pipe has been lowered into the trench (bell hole welding) shall be carried
out only where sufficient clearance has been provided to enable the welders to exercise
normal welding skills and abilities, and to allow sufficient space for NDT.
During tie-in operations CONTRACTOR shall avoid actions or operations that will induce a
curvature that, with the other acting loads, results in an equivalent stress on pipeline
geometry greater than the allowable the specific minimum yield strength (SMYS) of the pipe
material, CONTRACTOR shall prepare calculation to be included in CEP.
CONTRACTOR shall perform the tie-in as soon as practicable after lowering-in of the pipe
strings and shall observe the maximum and minimum tie-in temperatures, based on the
prevailing temperature conditions.
Extended periods between lowering-in and tie-in shall only be allowed when the specified
tie-in temperature is not reached.
Short lengths of pipe required for tie-ins or matching pieces ('pups') shall be cut from
undamaged pipe. The minimum length of any cut length or 'pup' shall be 2.5 metres. All
cutting shall be performed by an approved pipe cutter or thermal cutting and bevelling
machine. Manual cutting shall not be permitted.
CONTRACTOR shall carefully remove sufficient coating to allow for the cutting of pipes and
their subsequent welding, NDT and re-coating, in accordance with the requirements of
project specifications.
All pups of 2.5 m or more in length that are cut off at the tie-in points shall not be allowed to
be accumulated but shall be moved ahead daily by CONTRACTOR as the Work progresses
and welded into the line. In no case shall more than three welds be included in an 10 m long
pipe section.
All tie-in welds shall be coated and 100 percent radiographycally inspected.
It is preferred to perform tie-in weld over the trench at ground level. When it is necessary to
make tie-in welds in the trench, a bell hole shall be dug on the sides and under the pipe to
provide adequate clearances for making the tie-in welds properly. Trench boxes or sheet
piled boreholes shall be installed to prevent collapse. The pipe ends shall be lined up for
welding using an external line-up clamp.
Under no circumstances shall the line be lefts in tension after tie-in operation has been
completed.
Tie-in welds in restrained sections of the line shall be made when pipe temperature is at
minimum (during the coolest part of the day).
16.2
FINAL TIE-INS
Tie-ins of adjacent pipeline sections already pressure tested shall be carried out with a
single weld whenever possible; should the pipe sections not overlap or have appropriate
length, single pups with a minimum length of 2.5 m, previously hydrostatically tested, shall
be used to make the tie-ins.
16.3
PROTECTION AGAINST INDUCED VOLTAGE EFFECTS
Pipelines installed within areas of high voltage lines may be electrically influenced by these
lines. The induced voltage could be hazardous to the personnel working on the pipelines.
Prior to performing the work, CONTRACTOR shall specify and submit, for COMPANY
approval, detailed safety procedures for the mitigation of the induced voltage effects.
Induced voltage may also have an adverse affect on welding performance.
eni spa
exploration & production division
17.
CLEAN-UP AND LAND RESTORATION
17.1
CLEAN UP
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 52 of 59
Cleaning up the ROW shall include, but not necessarily be limited to, the following:
•
•
•
•
•
Cleaning up and disposal of all refuse, debris, waste and rubbish such as brush,
rock, skids, barrels, drums, cans, etc., resulting from the construction operations.
Removal of all equipment, tools and facilities used in the execution of the work.
Removal of all surplus and defective materials.
Reinstatement of the surrounding ground to a condition equivalent to that prior to
the works.
Reinstatement of all natural drainage courses to their original condition or to any
condition required by COMPANY.
Any holes, ridges, cuts and other surface irregularities resulting from CONTRACTOR’s
activities shall be filled and levelled. Surrounding ground shall be restored to a stable and
usable condition as may be reasonably required and consistent with the condition of the
ground prior to pipeline construction.
17.2
RESTORATION
Reinstatement of the land as closely as possible to its original condition is a target of the
pipeline construction completion.
Immediately upon the completion of backfilling operations, CONTRACTOR shall clean up
the ROW and adjoining areas used for the construction to the satisfaction of COMPANY.
During land restoration works the ROW shall be carefully graded and in mountain/hilly
areas, CONTRACTOR shall install erosion-prevention measures such as interceptor dikes,
which are small earthen mounds constructed across the ROW to divert water.
The areas affected by construction shall be brought back to existing conditions before
construction.
• The restoring operations shall be carried out by an appropriate team, which will
remain operating until the end of the whole work. Restoration shall be performed
according to the requirements of the relevant central and/or local authorities.
• The personnel shall be trained on necessary precautions to be taken in case of
emergency (e.g., fire, leakage, etc.).
• Alternative pipeline construction techniques shall be used in order to minimize the
impacts on the adjacent properties and terrain.
• The refilled soil should be compacted to an appropriate extent, wherever possible,
leaving a sufficient amount of heap on the pipe route against further compaction.
• The heap mentioned in the above item should not impede human and/or wildlife
from crossing the pipe ROW.
• The access roads to the ROW, which will not be used for maintenance purposes
after the completion of the Project, shall be duly closed, and the terrain shall be
restored so that it would be brought back to its original conditions before the
construction
All waste materials, branches, stubs, support pieces used for pipes, large stones,
pebbles, excess earth from excavation, etc. shall be removed, collected and
transferred to disposal areas according to the indications of relevant authorities
(e.g., municipalities, governorships, etc.). The latter may be spread on the ground
surface if permitted by the authorities and approved by the owners of the areas
involved. Waste, unnatural dirt and polluting matters have to be deposited in areas
foreseen or prepared for such purpose.
• All pipes, pipe stubs and any other material which have not been used for the
assembly or which are abandoned along the line due to defects or other causes
shall be transferred and stored in places indicated by relevant authorities.
eni spa
exploration & production division
•
•
•
•
•
•
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 53 of 59
Site clearance shall be performed by manpower or appropriate machinery. Dozers
should not be preferred, if possible, for the reason that their blades displace the
topsoil layer, particularly if it is thin, and mix it with the lower ground strata.
ROW shall be monitored during and for some period after the pipeline is buried to
assure proper mechanical functions or to identify structural conditions resulting in
leaks or ruptures. In case of such conditions, immediate action shall be taken to
prevent or mitigate the disturbance to the environment.
Camp sites shall be set up giving minimum disturbance to the environment, and
when they are removed, the area shall be restored, so that it would be brought back
to conditions at least equivalent to those existing before the construction.
Temporary storage areas shall be restored, and brought back to conditions not
lower than those existing before construction.
Borrow quarries shall be restored, and brought back to conditions not lower than
those existing before construction, if feasible. Otherwise, they shall be restored to a
level determined by the authorities.
All restoration works shall be completed until the end of the time frames settled for
the reinstatement of the areas and quarries utilized for the project.
Clean up work shall be continuous and will be inspected by COMPANY accordingly. All
general or first pass clean-up shall be completed ahead of the hydrostatic testing operation.
CONTRACTOR shall be responsible for all claims which may result from damage caused off
the right of way and shall make all necessary repairs and restorations at his own expense.
CONTRACTOR and COMPANY shall cooperate to contact landowners and proper
authorities to procure their consent and instructions in order to leave their premises in a
condition acceptable to such owners and authorities.
CONTRACTOR shall perform, at his own expense, all repair work necessary to restore any
facilities and utilities cut or damaged by his operations to their original condition. All
restoration work shall be to the CONTRACTOR shall furnish asphalt or other paving
materials and sand, gravel, shell or other subgrade materials, to restore cut road to their
original condition and grade to the satisfaction of the owner / authority. The shoulders,
ditches, banks and slopes of all roads crossed shall be restored to their former condition in
accordance with the drawings and specifications.
17.3
RESTORATION OF AGRICULTURAL AREAS
Agricultural areas include any area that is currently being used or can be used for
agricultural purposes.
The most common items to be compiled with while passing through an agricultural area are
given below. Nevertheless, there may be other requirements of the above authorities, which
shall be learned via official contacts.
The following cares shall be followed by CONTRACTOR:
•
•
•
•
•
the topsoil, when it has to be put aside during excavation, shall be spread again on
the site with utmost care, providing a uniform thickness of the layer, not leaving
behind stones and materials coming from the lower ground strata.
Necessary precautions are to be taken to minimize the disturbance to the vicinity.
The excess earth due to the volume of the buried pipeline shall be spread properly
to leave an appropriately level ground surface. The amount of hump to be left on the
pipeline against settlement of the soil in time shall be designed carefully and owners
of the land shall be informed on the necessity of leaving such a hump.
If areas with particular vegetation (olives or fruit trees) have been crossed, shall be
re-vegetated after construction so that they would be brought back to conditions at
least equivalent to those existing before the construction.
After the construction process, the areas except for the ROW shall be opened to the
owners’ usage with the condition of obeying security requirements.
eni spa
exploration & production division
18.
INSTALLATION OF SPECIAL FITTINGS
18.1
GENERAL
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 54 of 59
CONTRACTOR can assemble and test special fittings either in the workshop, at job location
or directly in the trench, providing that no cuts or pipe replacements and welding are made
after the tests have been carried out and the fittings are handled according to the provisions
of the specification without compromising the integrity of the equipment and their coatings, if
any.
Welds shall be performed according to the procedures established in the welding
specification and they shall be inserted in the line according to the procedures.
18.2
INSTALLATION OF FLANGES
The CONTRACTOR shall weld the flanges, the bead thickness of which is usually different
from the pipeline thickness, to spool pieces having a minimum length equal to the higher
value between 0.60 m and 2 times the diameter of the spool.
18.3
INSTALLATION OF SHUT-OFF VALVES OR FITTINGS
Shut-off valves up to 24” diameter (609.59 mm) can be assembled to the pipes or to the bypass valves either in the workshop or at job location or in the trench.
The fittings with 26” (660.39 mm) to (836.58 mm) diameters can only be assembled at job
location or in the trench. Diameters exceeding 34” can be assembled in the trench only.
The procedures for more complicated fittings (i.e. shut-off valves with branch point) shall be
agreed by the CONTRACTOR and the Client's representative.
The valves shall be handled using suitable equipment to avoid damages to the external
coating, if any. Lifting and handling equipment shall not come into contact with delicate
parts such as hand wheel, flanges, by-pass, etc.
The shut-off valves shall be with the axis in horizontal position or with inclination not
exceeding that established by the Manufacturer. The installation shall be carried out so as
not cause stresses to the tie-in welds; therefore the pipeline shall be rectilinear for a certain
length both upstream and downstream of the valve.
The CONTRACTOR shall lay the shut-off fitting on the foreseen foundations. The
foundations shall be provided with a steel plate depending on the weight to be supported.
One or more insulating sheets (neoprene) shall be placed between the steel plate and the
valve, according to the instructions of the drawings.
Disassembling or loosening of flanged connections, not tested in place, is not allowed.
The CONTRACTOR shall assemble flanged valves and flanged pipe sections before
installation after suitable preparation.
During welding for connection to the pipeline, the valves shall remain completely open and
shall meet, at the same time, any other instruction of the Manufacturer.
Valves and relevant fittings shall be coated by CONTRACTOR, after suitable preparation in
accordance with the specifications included in the Contractual documents.
18.4
INSTALLATION OF INSULATION JOINTS
The insulating joints to be installed in the pipeline are usually enbloc type (bell and spigot) fit
for being butt welded. Joints shall be checked before installation to verify electrical
resistance, coating and bell sealing.
The joints shall be stored, handled and assembled taking all necessary precautions in order
to avoid stresses. Moreover, CONTRACTOR must remember that the original pipe sections
shall not be reduced.
The CONTRACTOR shall install the joint the buried pipeline keeping the external
temperature as close as possible to the pipeline operating temperature. The joints shall be
laid in a fine sand bed and installed in rectilinear pipeline sections.
eni spa
exploration & production division
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 55 of 59
During tie-in welding the CONTRACTOR shall avoid heat propagation towards the joints
which hall be kept cool by applying of rags.
The CONTRACTOR shall externally coat the joints and pipe sections using plastic tape or
other materials indicated in the corresponding specification. The coating with plastic tape
includes cleaning by solvents, primer application, tapering and filling with approved mastics
and helicoidal wrapping. Before backfilling the CONTRACTOR shall check the integrity of
the applied coating by verifying the electrical insulation.
eni spa
exploration & production division
19
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 56 of 59
CATHODIC PROTECTION
Permanent CP shall be achieved by an impressed current systems constituted by CP
stations located along the pipeline at some line valve facilities.
The anode ground bed shall be surface type if the soil electric resistivity shall be less than
100 Ohm or deep well if the resistivity shall be high.
The deep well shall have a borehole encased by a proper steel casing to avoid the soil
collapse.
Along the pipeline route a number of monitoring test stations shall be installed as follows:
•
•
•
•
•
At crossing with existing foreign pipelines
At both ends of parallelism with existing foreign pipeline, if closer than 20 m and
longer than 1 km
At steel cased road or railway crossing
At insulating joint
Every 1 km, if not monitored by the above test stations
Temporary CP shall be provided when permanent one cannot be achieved within 3 months
since pipeline buried. Magnesium pre-packaged sacrificial anodes shall be installed using
the monitoring test stations.
eni spa
exploration & production division
20.
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 57 of 59
VALVE STATIONS
Valve Stations shall be located as indicated in the Project drawings and CONTRACTOR
shall comply with the mechanical, civil, electrical and instrumentation construction
requirements when developing the construction procedure that shall be submitted for
COMPANY approval.
All obstacles preventing the execution of the work or the construction of the plant in the
areas destined to receive same shall be removed. On completion of the clearance work, the
area shall be appropriately levelled to allow the construction work to proceed.
CONTRACTOR shall also:
•
•
•
•
•
•
•
•
•
Provide a necessary embankment when foreseen by specifications and project
drawings.
Construct all necessary supports.
Construct the anchor blocks/expansion loops provided for in the design
Construct an access road to the plant suitable for the passage of vehicles
Install a boundary fence/wall
Install a Line Valve House - Shelters
Install a building
Construct paving
On completion of the works, reinstate the area surrounding the fence.
Valves, fittings and appurtenances shall be properly supported and anchored in their final
location.
The material shall be handled by using suitable equipment and method so as to avoid
impact stress and damage to the coating. Hoisting and handling shall never be done at the
most delicate parts such as hand wheels, stems, flanged joints, by-pass and other parts that
could be damaged.
Underground valves shall be installed in a horizontal position, preventing tension at welded
joints: for this purpose sufficient pipeline section upstream and downstream from the valve
shall be laid aligned with valve.
The above-ground sections at valve stations shall be supported in a substantial and
workmanlike manner, so as to prevent or damp out excessive vibration, and shall be
anchored sufficiently to prevent undue strain on the pipeline.
The CONTRACTOR shall lay the shut-off fitting on the foundations foreseen in the project.
The foundations shall be provided with a steel plate depending on the weight to be
supported. One or more insulating sheets (neoprene) shall be placed between the steel
plate and the valve, according to the instructions of the drawings.
It is not allowed to disassemble or loosen flanged connections, not tested in place,.
The CONTRACTOR shall assemble flanged valves and flanged pipe sections before
installation after suitable preparation.
During welding for connection to the pipeline, the valves shall remain completely open and
shall meet, at the same time, any other instruction of the Manufacturer.
Valves and relevant fittings shall be coated by CONTRACTOR, after suitable preparation in
accordance with the specifications included in the Contractual documents.
Prior to commencing the work, CONTRACTOR shall submit a stress analysis report to
COMPANY for approval.
The block valves shall be tested separately, from the pipeline.
No cut or replacement in the valve assembly shall be allowed after hydrostatic testing.
During installation all the valve supplier’s requirements must be fully complied with.
Any valves damaged as a result of not complying with this requirement shall be replaced by
CONTRACTOR at his own expense.
eni spa
exploration & production division
20.1
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 58 of 59
ABOVE GROUND PIPING
Above ground piping shall be installed levelled and squared in all directions and true to line
and grade as established on-site. Heating or bending to correct any misalignment shall be
strictly prohibited.
Pipe, fittings, valves, etc. shall be cleaned on the inside by approved methods prior to
assembly. After assembly the piping shall be cleaned and painted.
Above ground piping shall be adequately supported to maintain alignment and prevent
excessive stresses and vibrations. Pipe supports shall be designed by CONTRACTOR and
the design drawings submitted to COMPANY for approval.
20.2
CORROSION PROTECTION OF ABOVE GROUND PIPING
Unless otherwise specified, all the above ground piping sections shall be painted in
accordance with project specification.
CONTRACTOR shall provide COMPANY with all painting procedures for approval prior to
the commencement of any painting works.
CONTRACTOR shall be responsible for the cost of testing, repairing or replacing of any
paintwork.
eni spa
exploration & production division
21
03516.PLI.MEC.SDS
Rev. 1 July 2012
Sh. 59 of 59
PIPELINE SIGNALLING
CONTRACTOR shall supply and install the pipeline kilometre markers, aerial markers and
pipeline warning signs at locations as specified by COMPANY.
A warning sign installed on each side of the crossing shall clearly identify each road and
track crossing.
Pipeline warning signs shall be sufficiently elevated above ground to allow them to be
clearly seen from a distance and remain visible above normal vegetation.
CONTRACTOR shall furnish and install the pipeline kilometre marker, aerial markers and
pipeline warning signs, at locations and of details as shown on the drawing.
22
TELECOMUNICATION CABLE AND FACILITIES
A telecommunication fibre optic cable shall be installed inside the pipeline trench for the
monitoring and detecting the pipeline leakages, to verify pipeline operational parameters
and to prevent failure of pipelines installed in landslide areas, to optimize oil production from
wells, and to detect hot spots in high-power cables.
The fibre optic cable shall be pulling into the steel casing in the crossings, as per related
dedicated specifications and as indicated by engineering Documentation.
23
COMPLETION OF CONSTRUCTION WORK
The work activities completion has to ensure the successful transition of the pipeline from
construction to commissioning.
•
•
•
•
•
•
•
•
•
•
•
•
Conformity checks;
Hydrostatic, pneumatic and other field testing;
Cleaning of all lines and equipment by flushing or blowing;
Installation of all instruments;
Checking of electrical and instrumental connections;
Checking of earthing (grounding) system;
Painting activities, as required;
Removal of all temporary mechanical completion works;
General area clean up
Completion of restoration work
The issuance of proper mechanical completion certifications required;
Preparation of As built dossiers.
CONTRACTOR shall submit to COMPANY for approval fully detailed specifications,
designs, calculations, procedures and schedules as required to complete the completion of
the work.