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DEP SPECIFICATION
SHELL AND TUBE HEAT EXCHANGERS
(AMENDMENTS/SUPPLEMENTS TO ISO 16812:2007)
DEP 31.21.01.30-Gen.
February 2011
DESIGN AND ENGINEERING PRACTICE
DEM1
© 2011 Shell Group of companies
All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, published or transmitted, in any form or by any means, without the prior
written permission of the copyright owner or Shell Global Solutions International BV.
DEP 31.21.01.30-Gen.
February 2011
Page 2
PREFACE
DEP (Design and Engineering Practice) publications reflect the views, at the time of publication, of Shell Global
Solutions International B.V. (Shell GSI) and, in some cases, of other Shell Companies.
These views are based on the experience acquired during involvement with the design, construction, operation and
maintenance of processing units and facilities. Where deemed appropriate DEPs are based on, or reference
international, regional, national and industry standards.
The objective is to set the recommended standard for good design and engineering practice to be applied by Shell
companies in oil and gas production, oil refining, gas handling, gasification, chemical processing, or any other such
facility, and thereby to help achieve maximum technical and economic benefit from standardization.
The information set forth in these publications is provided to Shell companies for their consideration and decision to
implement. This is of particular importance where DEPs may not cover every requirement or diversity of condition at
each locality. The system of DEPs is expected to be sufficiently flexible to allow individual Operating Units to adapt the
information set forth in DEPs to their own environment and requirements.
When Contractors or Manufacturers/Suppliers use DEPs, they shall be solely responsible for such use, including the
quality of their work and the attainment of the required design and engineering standards. In particular, for those
requirements not specifically covered, the Principal will typically expect them to follow those design and engineering
practices that will achieve at least the same level of integrity as reflected in the DEPs. If in doubt, the Contractor or
Manufacturer/Supplier shall, without detracting from his own responsibility, consult the Principal.
The right to obtain and to use DEPs is restricted, and is typically granted by Shell GSI (and in some cases by other Shell
Companies) under a Service Agreement or a License Agreement. This right is granted primarily to Shell companies and
other companies receiving technical advice and services from Shell GSI or another Shell Company. Consequently, three
categories of users of DEPs can be distinguished:
1)
Operating Units having a Service Agreement with Shell GSI or another Shell Company. The use of DEPs by
these Operating Units is subject in all respects to the terms and conditions of the relevant Service Agreement.
2)
Other parties who are authorised to use DEPs subject to appropriate contractual arrangements (whether as part
of a Service Agreement or otherwise).
3)
Contractors/subcontractors and Manufacturers/Suppliers under a contract with users referred to under 1) or 2)
which requires that tenders for projects, materials supplied or - generally - work performed on behalf of the said
users comply with the relevant standards.
Subject to any particular terms and conditions as may be set forth in specific agreements with users, Shell GSI
disclaims any liability of whatsoever nature for any damage (including injury or death) suffered by any company or
person whomsoever as a result of or in connection with the use, application or implementation of any DEP, combination
of DEPs or any part thereof, even if it is wholly or partly caused by negligence on the part of Shell GSI or other Shell
Company. The benefit of this disclaimer shall inure in all respects to Shell GSI and/or any Shell Company, or companies
affiliated to these companies, that may issue DEPs or advise or require the use of DEPs.
Without prejudice to any specific terms in respect of confidentiality under relevant contractual arrangements, DEPs shall
not, without the prior written consent of Shell GSI, be disclosed by users to any company or person whomsoever and
the DEPs shall be used exclusively for the purpose for which they have been provided to the user. They shall be
returned after use, including any copies which shall only be made by users with the express prior written consent of
Shell GSI. The copyright of DEPs vests in Shell Group of companies. Users shall arrange for DEPs to be held in safe
custody and Shell GSI may at any time require information satisfactory to them in order to ascertain how users
implement this requirement.
All administrative queries should be directed to the DEP Administrator in Shell GSI.
DEP 31.21.01.30-Gen.
February 2011
Page 3
TABLE OF CONTENTS
PART I
1.1
1.2
1.3
1.4
1.5
1.6
1.7
INTRODUCTION ........................................................................................................5
SCOPE........................................................................................................................5
DISTRIBUTION, INTENDED USE AND REGULATORY CONSIDERATIONS .........5
DEFINITIONS .............................................................................................................5
CROSS-REFERENCES .............................................................................................6
SUMMARY OF MAIN CHANGES...............................................................................6
COMMENTS ON THIS DEP .......................................................................................6
DUAL UNITS...............................................................................................................6
PART II
1.
1.1
1.2
2.
2.1
3.
GENERAL...................................................................................................................7
DESIGN SPECIFICATIONS .......................................................................................7
THERMAL DESIGN AND RATING.............................................................................7
MATERIALS SPECIFICATIONS ................................................................................8
ORDERING.................................................................................................................9
SCOPE OF SUPPLY ..................................................................................................9
DESIGN RULES .......................................................................................................10
PART III
3.
4.
5.
6.
6.1
6.2
6.3
7.
7.1
7.2
7.3
7.4
7.5
7.6
7.7
7.8
7.9
7.10
7.11
7.13
7.14
7.15
7.16
8.
8.1
8.2
8.3
8.4
8.5
9.
9.1
9.2
9.5
9.6
9.7
9.8
9.9
9.10
9.11
9.12
10.
AMENDMENTS/SUPPLEMENTS TO ISO 16812....................................................11
TERMS AND DEFINITIONS .....................................................................................11
GENERAL .................................................................................................................12
PROPOSALS............................................................................................................13
DRAWINGS AND OTHER REQUIRED DATA .........................................................14
OUTLINE DRAWINGS AND OTHER SUPPORTING DATA....................................14
INFORMATION REQUIRED AFTER OUTLINE DRAWINGS ARE REVIEWED .....14
Reports and records .................................................................................................15
DESIGN ....................................................................................................................16
DESIGN TEMPERATURE (AND PRESSURE) ........................................................16
CLADDING FOR CORROSION ALLOWANCE........................................................16
SHELL SUPPORTS..................................................................................................17
STATIONARY HEAD ................................................................................................18
FLOATING HEAD .....................................................................................................19
TUBE BUNDLE.........................................................................................................20
NOZZLES AND OTHER CONNECTIONS ...............................................................29
FLANGED EXTERNAL GIRTH JOINTS...................................................................31
EXPANSION JOINTS ...............................................................................................34
GASKETS .................................................................................................................35
HANDLING DEVICES...............................................................................................36
CARBON STEEL IN WET HYDROGEN SULFIDE SERVICE .................................37
KETTLE-TYPE REBOILERS AND EVAPORATORS...............................................37
EMBAFFLETM HEAT EXCHANGERS.......................................................................39
TRANSITIONS..........................................................................................................39
MATERIALS..............................................................................................................40
GENERAL .................................................................................................................40
GASKETS .................................................................................................................40
TUBES ......................................................................................................................40
EXTERNAL BOLTING ..............................................................................................41
CATHODIC PROTECTION.......................................................................................42
FABRICATION..........................................................................................................43
SHELLS ....................................................................................................................43
PASS-PARTITION PLATES .....................................................................................43
WELDING .................................................................................................................43
HEAT TREATMENT .................................................................................................44
DIMENSIONAL TOLERANCES................................................................................44
GASKET CONTACT SURFACES OTHER THAN NOZZLE-FLANGE FACINGS....45
TUBE HOLES ...........................................................................................................45
TUBE-TO-TUBESHEET JOINTS .............................................................................45
ASSEMBLY...............................................................................................................45
INSULATION SUPPORTS........................................................................................46
INSPECTION AND TESTING...................................................................................47
DEP 31.21.01.30-Gen.
February 2011
Page 4
10.1
10.2
10.3
10.4
10.5
10.6
11.
11.1
11.2
12.
12.1
12.2
ANNEX A
ANNEX B
ANNEX C
QUALITY ASSURANCE ...........................................................................................47
QUALITY CONTROL ................................................................................................47
PRESSURE TESTING..............................................................................................48
NAMEPLATES AND STAMPINGS...........................................................................49
TEST RING AND TEST FLANGE ............................................................................49
REPAIRS ..................................................................................................................49
PREPARATION FOR SHIPMENT............................................................................50
PROTECTION ..........................................................................................................50
IDENTIFICATION .....................................................................................................50
SUPPLEMENTAL REQUIREMENTS .......................................................................52
GENERAL .................................................................................................................52
DESIGN ....................................................................................................................52
RECOMMENDED PRACTICES ...............................................................................53
SHELL AND TUBE HEAT EXCHANGER CHECKLIST ...........................................53
SHELL AND TUBE HEAT EXCHANGER DATA SHEETS.......................................53
PART IV
REFERENCES .........................................................................................................54
APPENDICES
APPENDIX 1
MATERIALS FOR USE IN SHELL AND TUBE HEAT EXCHANGERS..........57
APPENDIX 2
METHOD OF DETECTION OF HARMFUL OXIDE FILMS ON COPPERNICKEL ALLOY TUBES ..................................................................................64
APPENDIX 3
DRAWINGS .....................................................................................................66
DEP 31.21.01.30-Gen.
February 2011
Page 5
PART I INTRODUCTION
1.1
SCOPE
This DEP specifies requirements and gives recommendations for the design and
construction of shell and tube heat exchangers having a bare tube surface area of greater
than 0.5 m2. This DEP is not intended for hairpin type heat exchangers or for pressurized
water-cooled (or glycol-cooled) seal-oil coolers, lube-oil coolers, jacket water coolers for
rotating equipment, vacuum-operated steam surface condensers, feed water heaters, or
alkylation contactor bundles of proprietary design.
Part III of this DEP is written in the form of amendments and supplements to
ISO 16812:2007. Part III follows the clause numbering of ISO 16812 for easy reference.
All clauses of ISO 16812 not modified by this DEP remain valid as written.
This document is intended primarily for use by the Supplier and shall be included in the
purchase requisition along with the heat exchanger data/requisition sheet
(DEP 31.21.00.93-Gen., or equivalent), supplementary technical requirements, project
specifications, and any other DEPs required to provide a complete set of design, materials,
fabrication, inspection and testing instructions to the Supplier.
This DEP contains mandatory requirements to mitigate process safety risks in accordance
with Design Engineering Manual DEM 1 – Application of Technical Standards.
This is a revision of the DEP of the same number dated May 2004; see (1.5) regarding the
changes.
1.2
DISTRIBUTION, INTENDED USE AND REGULATORY CONSIDERATIONS
Unless otherwise authorised by Shell GSI, the distribution of this DEP is confined to Shell
companies and, where necessary, to Contractors and Manufacturers/Suppliers nominated
by them. Any authorised access to DEPs does not for that reason constitute an
authorization to any documents, data or information to which the DEPs may refer.
This DEP is intended for use in facilities related to oil and gas production, gas handling, oil
refining, chemical processing, gasification, distribution and supply/marketing. This DEP
may also be applied in other similar facilities.
When DEPs are applied, a Management of Change (MOC) process should be
implemented; this is of particular importance when existing facilities are to be modified.
If national and/or local regulations exist in which some of the requirements could be more
stringent than in this DEP, the Contractor shall determine by careful scrutiny which of the
requirements are the more stringent and which combination of requirements will be
acceptable with regards to the safety, environmental, economic and legal aspects. In all
cases the Contractor shall inform the Principal of any deviation from the requirements of
this DEP which is considered to be necessary in order to comply with national and/or local
regulations. The Principal may then negotiate with the Authorities concerned, the objective
being to obtain agreement to follow this DEP as closely as possible.
1.3
DEFINITIONS
1.3.1
General definitions
The Contractor is the party that carries out all or part of the design, engineering,
procurement, construction, commissioning or management of a project or operation of a
facility. The Principal may undertake all or part of the duties of the Contractor.
The Manufacturer/Supplier is the party that manufactures or supplies equipment and
services to perform the duties specified by the Contractor.
NOTE:
The terms Supplier and Manufacturer as used in this DEP are synonymous with the term Vendor (as
used in ISO 16812:2007) depending on the context in which the term is used.
DEP 31.21.01.30-Gen.
February 2011
Page 6
The Principal is the party that initiates the project and ultimately pays for it. The Principal
may also include an agent or consultant authorised to act for, and on behalf of, the
Principal.
NOTE:
The term Principal as used in this DEP is synonymous with the term Purchaser (as used in
ISO 16812:2007).
The word shall indicates a requirement.
The capitalised term SHALL [PS] indicates a process safety requirement.
The word should indicates a recommendation.
1.4
CROSS-REFERENCES
Where cross-references to other parts of this DEP are made, the referenced section
number is shown in brackets. Other documents referenced by this DEP are listed in
(Part VI).
1.5
SUMMARY OF MAIN CHANGES
This DEP is a revision of the DEP of the same number dated May 2004. The following are
the main, non-editorial changes.
In this revision, process safety requirements have been indicated by the use of the
capitalised term "SHALL [PS]".
Other than that, this has been a complete rewrite and is based on the 2007 edition of
ISO 16812, so it is impractical to summarise all changes here.
1.6
COMMENTS ON THIS DEP
Comments on this DEP may be sent to the Administrator at standards@shell.com, using
the DEP Feedback Form. The DEP Feedback Form can be found on the main page of
“DEPs on the Web”, available through the Global Technical Standards web portal
http://sww.shell.com/standards and on the main page of the DEPs DVD-ROM.
1.7
DUAL UNITS
In this DEP, the International System of units (SI) shall be understood to prevail over US
Customary (USC) units. USC units are provided in brackets following the SI units for
information.
DEP 31.21.01.30-Gen.
February 2011
Page 7
PART II GENERAL
Part III of this DEP is written as amendments and supplements to ISO 16812:2007.
Wherever reference is made to ISO 16812, it shall be understood to mean ISO 16812:2007
as amended/supplemented by this DEP.
For ease of reference, the clause numbering of ISO 16812 has been used throughout
Part III of this DEP.
Clauses in ISO 16812, which are not mentioned in this DEP, shall remain valid as written.
1.
DESIGN SPECIFICATIONS
1.1
THERMAL DESIGN AND RATING
1.1.1
The TEMA type and other details of the design including tube count, tube diameter, tube
thickness, tube length, number of tube passes, tube layout angle, tube pitch, number of
shellside cross-passes, baffle spacing, baffle cut and orientation shall be as specified on
the data/requisition sheet (DEP 31.21.00.93-Gen., or equivalent) by the Contractor. The
Supplier may propose an alternate design for consideration, provided the proposal includes
the base design specified by the Contractor.
1.1.2
The Supplier shall provide a mechanical and thermal performance guarantee, regardless of
the party who completes the initial thermal design or rating. In the case of a proprietary
design, the Contractor shall contact the Principal to agree on the calculation method and
responsibility.
1.1.3
Designs with helical baffles, rod-baffles, EMBafflesTM, twisted tubes, low-finned tubes or
other enhanced tube types (including tube inserts) may only be used with the agreement of
the Principal. This requirement is not intended to impede the application of enhanced heat
transfer technology; the intention is to assist in improving the likelihood of successful
applications.
1.1.4
Floating head exchangers with a nozzle connection to the floating head cover, commonly
referred to as a “tail-pipe” nozzle, with expansion joint, and fixed tubesheet exchangers
shall be designed to accommodate normal operating cases in accordance with Part III
clause 7.9.2.c).
The Contractor SHALL [PS] also provide steady state and any applicable transient details
for predictable upset cases (e.g. loss of flow, loss of upstream wash water injection, etc.),
start-up and shut-down cases (including steam-out). Flow rates, inlet pressures, inlet
temperatures, physical properties, and heating curves (where applicable) for both the hot
and cold streams shall be provided for each case. An expansion joint design checklist (per
ISO 16812 Annex C, or equivalent) shall be provided with the data/requisition sheet by the
Contractor.
Shell-and-tube metal temperatures for analysis of thermal stresses SHALL [PS] be those
that produce the most adverse differential expansion conditions that can occur, including
the effects with only one (1) side fouled. The minimum number of cycles for each case,
other than the normal operating case, shall be specified by the Contractor based on 10
times the number of cycles expected in a ten year period.
If the data provided by the Contractor is considered to be insufficient for checking purposes,
it is the responsibility of the Supplier to request further information from the Contractor.
The materials and supplier of thin-wall bellows expansion joints shall be approved by the
Principal.
1.1.5
All exchangers SHALL [PS] be analyzed for flow induced mechanical vibration. All
exchangers with single phase vapour at the shell side inlet shall also be analyzed for
acoustic vibration noise.
For exchangers with vapour or two-phase flow on the shell side, or for those with baffle cuts
which are parrallel to the inlet/outlet nozzle centrelines, the vibration analysis SHALL [PS]
be verified based on the actual tube bundle design details provided in the Supplier’s
DEP 31.21.01.30-Gen.
February 2011
Page 8
general arrangement or detailed drawings (actual baffle locations, actual shell entrance and
exit areas, actual tube layout) rather than the tube bundle details assumed or specified by
the Contractor on the data/requisition sheet at the enquiry stage.
In the event of disagreements about tube vibration, the HTRI Xist program shall be used as
a basis for assessing tube vibration. The use of the HTRI Xvib program shall only be used
with the approval of the Principal.
1.1.6
Prior to completing the design, the Contractor shall determine all restrictions on bundle size
(diameter, length, weight) and any other special provisions for bundle maintenance based
on the bundle pulling, handling, or cleaning equipment used at the operating site
considering applicable economic considerations for exchanger foundations, structures, and
required maintenance access.
1.1.7
The checklist in Annex B (DEP 31.21.01.83-Gen.) shall be completed for each project and
included with the requisition documents in order to properly use this DEP as part of
purchase requisition.
1.2
MATERIALS SPECIFICATIONS
Appendix 1 provides a summary of material specifications and supplemental requirements
for a number of generalised service conditions specific to the tube side (tube bundle,
channel, floating head, etc.).
It is the responsibility of the Contractor to specify the materials for all pressure components
(including pass partition plates, bolting and gaskets) and non-pressure components
(including baffles, impingement devices, tie rods and sealing devices) on the
data/requisition sheet.
DEP 31.21.01.30-Gen.
February 2011
Page 9
2.
ORDERING
2.1
SCOPE OF SUPPLY
The Supplier shall provide the complete heat exchanger including:
a)
Bolts, nuts and gaskets for the interconnecting nozzles of directly flanged stacked
heat exchangers;
b)
Shims and bolting for the interconnecting supports of stacked heat exchangers,
c)
The number of spare sets of gaskets and bolting for construction and start up
spares shall be identified by the Contractor.
The Contractor shall specify when the Supplier is expected to install or provide insulation
clips, platform clips and other similar types of field scope or construction interfaces.
Excluded from the scope of supply are foundations, the erection of the supporting structure,
instruments, insulation, and fireproofing of saddles or structural support steel.
DEP 31.21.01.30-Gen.
February 2011
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3.
DESIGN RULES
In case of conflict between documents relating to an order, the following hierarchy shall
normally apply:
a)
Equipment data sheets and drawings;
b)
The purchase requisition;
c)
This DEP
d)
Other referenced DEPs;
e)
ISO 16812:2007.
In the event of a conflict, the Principal shall be consulted.
DEP 31.21.01.30-Gen.
February 2011
Page 11
PART III AMENDMENTS/SUPPLEMENTS TO ISO 16812
3.
TERMS AND DEFINITIONS
Add new terms:
3.14
hydrogen service
services in which the hydrogen partial pressure is greater than 700 kPa absolute [100 psia]
at any temperature
3.15
wet hydrogen sulphide service
service which normally contains dissolved H2S in a free water phase and can result in
environmental cracking of carbon steel materials
3.16
very toxic service
service containing substances that are very hazardous for the environment or human
health.
Note:
The Contractor shall indicate on the data/requisition sheet when the shell and/or tube side of the heat
exchanger is in hydrogen, wet hydrogen sulphide service or very toxic service.
DEP 31.21.01.30-Gen.
February 2011
Page 12
4.
GENERAL
4.1
Replace this clause by:
Shell and tube heat exchangers SHALL [PS] comply with the specified pressure design
code. The Contractor shall specify the applicable pressure design code on the
data/requisition sheets.
Where the the pressure design code is specified as ASME Section VIII, heat exchangers
SHALL [PS] comply with the applicable requirements in DEP 31.22.20.31-Gen. Shell and
tube heat exchangers shall be considered as “General Service” pressure vessels, except
for heat exchangers that are in the scope of Section 12, which SHALL [PS] be considered
as “Engineered Service” pressure vessels (refer to Section 12 of this DEP for more details).
Section VIII, Division 1 shall be applied for all heat exchangers unless approved otherwise
by the Principal.
Where another pressure design code is applicable the Contractor shall indicate the code
and associated pressure vessel DEP that applies.
ASME Part UHX, with the applicable allowable stresses, shall be applied regardless of the
pressure design code that is applied.
4.2
Replace this clause by:
Heat-exchanger construction shall conform to TEMA (latest edition), Class R, unless
otherwise specified on the data/requisition sheet. The Recommended Good Practice
section of TEMA shall also be applied, where applicable.
4.3
Add to this clause:
Exchangers shall be registered in accordance with the applicable regulations. Where the
applicable regulations have no requirements for pressure vessel registration, the
exchangers shall be registered with the U.S. National Board of Boiler and Pressure Vessel
Inspectors, if specified by the Contractor.
Add new clause:
4.8
When designed to the ASME code, heat exchangers shall be ASME Code stamped, unless
otherwise specified.
DEP 31.21.01.30-Gen.
February 2011
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5.
PROPOSALS
5.1
Replace this clause by:
The Supplier’s proposal shall include submission of a datasheet, containing all of the
pertinent design information specified on the Contractor’s data/requisition sheet.
When a tube count-shell diameter combination has been specified on the Contractor’s data
sheet and cannot be met, the following shall apply:
5.2
•
For shells fabricated from rolled plate, the shell inside diameter shall be increased
over that specified on the purchaser's data sheet, as required, to meet the specified
tube count and all other requirements which affect the tube layout, and shell and
bundle entrance areas in TEMA, ISO 16812 and this DEP;
•
For shells fabricated from pipe, the supplier shall state the maximum tube count
obtainable for the specified shell diameter. Adequacy of the suppliers tube count
will be determined on a case-by-case basis.
Add to this clause:
This includes special flow distributors, expansion joints, and floating head tailpipes and/or
flange details.
5.3
Add to this clause:
The use of distributor belts shall be approved by the Principal.
5.5
Add to this clause:
If the Supplier has no exceptions, there shall be a statement to this effect in the proposal.
DEP 31.21.01.30-Gen.
February 2011
Page 14
6.
DRAWINGS AND OTHER REQUIRED DATA
6.1
OUTLINE DRAWINGS AND OTHER SUPPORTING DATA
6.1.1
j) Add to this clause:
Corrosion allowance shall also be included when a value is specified separately for
internal components (i.e. tubes, bellows-type expansion joints, etc.). If no corrosion
allowance has been specified for the tubes, the available tube corrosion allowance
based on original tube outside diameter shall be calculated and shown on the outline
drawing;
Add new clauses:
6.1.2
w)
Heat exchangers that have titanium components shall have the following statement
on the outline drawing: "Titanium Equipment – Do not perform hot work without
approval of the Principal."
x)
Heat exchanger foundation loads due to empty, operating, and hydrotest weights,
wind and earthquake loads, and bundle pulling loads.
Replace this clause by:
The Supplier shall submit the results of the flow-induced vibration analysis, based on the
actual details of the design proposed, including the clearance between the shellside inlet
and outlet nozzles and the tube bundle, and the actual inlet, outlet and central baffle
spacing.
6.2
INFORMATION REQUIRED AFTER OUTLINE DRAWINGS ARE REVIEWED
6.2.2
Replace this clause by:
Weld maps, all proposed welding procedures and qualifications (including tube-totubesheet welding procedures and qualifications), and all supporting test results such as
impact tests, hardness tests, corrosion tests, as applicable, shall be submitted for approval,
prior to fabrication.
6.2.3
6.2.4
Add new clauses:
n)
Location of and notation of sub-supplier's component identification number;
o)
Vacuum ratings;
p)
Stress relieving requirements for U-tubes shall be included in the U-tube bend
schedule drawing;
q)
Requirements for spring washers, if applicable.
r)
Special handling, special hydrotest requirements, shipping or storage
requirements.
a) Add to this clause:
i.
Actual and allowable tube-to-tubesheet loadings for fixed tubesheet exchangers;
ii.
Pass partition plate and longitudinal baffle thickness calculations;
iii.
Expansion joint calculations;
iv.
Maximum allowable pressure (MAP) new (inclusive of corrosion allowance) and
cold and the maximum allowable working pressure (MAWP) hot and corroded.
The limiting component shall be identified.
v.
The static head due to the liquid level in vertical exchangers shall be included in
the thickness calculations for design pressure at the coincident design
temperature. The exchanger shall be assumed to be completely filled with
process fluid, or water, whichever has the higher density.
DEP 31.21.01.30-Gen.
February 2011
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b) Add to this clause:
Design calculations based on wind, seismic and transportation loads shall be provided,
when defined by the Contractor. The loading conditions shall not be less than those
specified in DEP 31.22.20.31-Gen;
c) Add to this clause:
The Supplier shall provide a tabulation of required bolt loadings (bolt torque, bolt stress,
and axial force values) for exchanger girth flange, channel cover flange, and floating
head flange bolting on the drawings;
Add new clauses:
6.2.5
e)
The Supplier shall submit the Inspection and Test Plan (ITP) for review and
approval. Surveillance requirements identified by the Contractor shall be
incorporated into the Supplier’s ITP;
f)
The Supplier shall submit materials handling and segregation procedures for all
stainless steel and alloy materials.
Replace this clause by:
Design calculations for heat exchanger supports, lifting devices, and pulling devices shall
be submitted. The documents provided shall include a table of foundation loads in all
operating cases (considering wind and seismic effects), the hydrotest case and the bundle
pulling case (for each bundle in stacked units).
6.3
Reports and records
Add new clauses:
n)
Tube expansion / tube wall reduction values be recorded on a tube layout drawing
and included in the Manufacturer’s data book;
o)
The wall thickness of six (6) randomly selected tubes shall be measured at a
distance of approximately 25 mm (1 in) behind the shell side face of the stationary
tubesheet. The thickness of each tubesheet shall be measured at one position. The
thicknesses shall be recorded on a tube layout drawing and included in the
Manufacturer’s data book.
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7.
DESIGN
7.1
DESIGN TEMPERATURE (AND PRESSURE)
The design temperature for both shell and tube side shall be provided on the
data/requisition sheet by the Contractor. However, after the maximum allowable working
pressure is established, the Supplier shall apply the highest possible design temperature
where reduction in allowable stress of the pressure components is not incurred, provided
the flange rating or vacuum rating is not limiting. The design temperature shall not be
increased beyond the value specified on the data/requisition sheet for floating head type
exchangers with a single tubepass, fixed tubesheet type exchangers, or for any exchangers
in hydrogen service.
7.1.3
Replace this clause by:
For floating head exchangers with a single tubepass and tailpipe, and for all fixed tubesheet
exchangers, the need for an expansion joint shall be determined by the Supplier based on
the operating cases specified on the equipment data/requisition sheet. In addition, all
alternate and upset operating cases specified by the Contractor in the Expansion Joint
Design Checklist shall be assessed.
Add new clause:
7.1.4
Where thermal and pressure cyclic loading has been specified, the Supplier shall
demonstrate, by a calculation method approved by the Principal, that the heat exchanger
will be able to sustain the specified loading for the duration of its service life. The Contractor
shall specify the pressure and/or temperature loading cycles and the required service life
for fatigue analysis.
Add new clause:
7.1.5
Design pressures (including any applicable vacuum ratings) for the shell and tube sides
shall be specified separately by the Contractor. The most unfavourable combination of
design pressures on the shell and tube side shall be used in the design and calculations for
components including tubes, tubesheets, floating heads, tailpipes and internal bellows.
Add new clause:
7.1.6
Where a differential design pressure between the tube side and shell side is specified on
the data/requisition sheet, a warning sign, stating the maximum differential design pressure
and the maximum differential test pressure, shall be located next to the nameplate. The use
of differential design pressure shall not be applied, unless approved by the Principal.
7.2
CLADDING FOR CORROSION ALLOWANCE
7.2.1
Replace this clause by:
The full thickness of the corrosion resistant cladding (including weld overlay) shall be used
as corrosion allowance, including the thickness of the weld overlay used to restore cladding
at welded joints. Where corrosion-resistant cladding (or weld overlay) is specified, it
SHALL [PS] apply to all wetted surfaces, including gasket grooves. Non-integral bonded
liners shall not be used unless approved by the Principal.
Pass partition plates shall be of the same alloy as the cladding to which they are welded.
The minimum cladding thickness at locations where the pass partition plates are welded
shall be 5 mm (3/16 in), when the base material requires post-weld heat treatment for either
Code or service reasons.
7.2.2
Replace this clause by:
Weld overlays applied for corrosion protection shall have sufficient thickness to provide the
specified chemical composition to a depth of at least 2.5 mm (3/32 in), unless otherwise
specified on the data/requisition sheet.
The minimum cladding (or weld overlay) thickness at the tube side tubesheet face shall not
be less than 6 mm (1/4 in) to permit welding of the tube ends to the tubesheet cladding.
DEP 31.21.01.30-Gen.
February 2011
Page 17
When the shell side face of a tubesheet is specified with cladding (or weld overlay) the
thickness of the cladding shall not be less than 10 mm (3/8 in). Rolling shall extend to within
3 mm (1/8 in) of the shell side clad or weld overlay face to provide a seal between the tubes
and the cladding or weld overlay.
Add new clause:
7.2.3
Non-bonded alloy liners shall not be used on manway or channel covers, unless approved
by the Principal.
7.3
SHELL SUPPORTS
7.3.1
Add to this clause:
The Supplier shall verify that number and size of anchor bolts are adequate for the bundle
pulling load, based on ASME SA 307 Grade M material or equivalent, unless otherwise
specified by the Contractor.
For stacked exchangers the fixed shell support and anchor bolts of the lower exchanger
shall be designed to withstand the longitudinal force applied at the centreline of the upper
heat exchanger bundle.
7.3.2
7.3.3
Add to this clause:
g)
The sliding plate underneath the sliding support saddle shall be in accordance with
Standard Drawing S 22.003.
h)
Saddles shall protrude beyond the bottom nozzles, including the drain nozzle with
blind flange, by at least 50 mm (2 in) to prevent damage to flange facings during
transport, storage and maintenance.
Add to this clause:
The saddle of the lower exchanger shall be configured as shown in Figure 1 when the lower
shell has a nominal diameter of 1000 mm (40 in) or greater. The outer gusset ribs shall
extend at least 50 mm (2 in) beyond the outside diameter of lower shell. Exchanger shells
shall not be stacked in combinations of more than two (2), unless approved by the
Principal.
Figure 1 Saddle for Stacked Heat Exchangers
7.3.5
Replace last sentence of this clause by:
The total length of the slots shall be equal to the anchor bolt diameter, plus twice the
theoretical thermal expansion of the shell (based on the shell side design temperature) plus
8 mm (5/16 in.).
Add new clause:
7.3.6
Flange bolting on connections between stacked shells shall be removable from one side of
the flange without removing the upper shell.
Add new clause:
7.3.7
Horizontal exchangers shall have supports designed in accordance with the revised L. P.
Zick analysis (Pressure Vessel and Piping; Design and Analysis, ASME, 1982).
DEP 31.21.01.30-Gen.
February 2011
Page 18
Add new clause:
7.3.8
Support design shall comply with UG-54 and Appendix G of the ASME Code. Exchanger
supports shall be continuously welded to the shell.
Add new clause:
7.3.9
Support brackets for vertical exchangers shall be in accordance with Standard Drawing
S 21.017. The Supplier shall verify that the support design is suitable for all defined
loadings including wind, seismic, and super-imposed external nozzle loads.
Add new clause:
7.3.10
When skirts are used to support vertical exchangers they shall be in accordance Standard
Drawing S 20.001 and with the additional requirements specified in DEP 31.22.20.31-Gen.
Add new clause:
7.3.11
A grounding lug shall be welded to one (1) of the exchanger supports in accordance with
Standard Drawing S 68.004.
Add new clause:
7.3.12
Stresses on exchanger supports resulting from nozzle external loads and different thermal
growth rates of stacked exchangers shall be included as super-imposed loads in designing
the supports, as applicable. Exchanger support reactions shall include these applicable
loads, and be shown on the drawings.
7.4
STATIONARY HEAD
7.4.2
Replace this clause by:
Pass partition plates (in both stationary heads and the floating heads) shall be designed,
per TEMA paragraph RCB-9.132, without corrosion allowance, to accommodate at least
three (3) times the maximum calculated clean pressure differential across each pass
partition plate.
In no case shall the minimum thickness be less than the value specified in TEMA
paragraph RCB-9.131. The use of rods, bars, etc. to stiffen pass partition plates is
acceptable. Calculations of the maximum allowable differential pressure across the pass
partition plate shall be submitted with the mechanical design calculations.
Add new clause:
7.4.3
For TEMA ‘B’ type bonnets, tubesheets shall extend to the same diameter as the
connecting flange and allow for independent hydrostatic test of both the shell and tube
sides, without the use of a test ring.
Add new clause:
7.4.4
When an axial nozzle is used on stationary heads, the minimum distance from the
intersection of the nozzle centreline and the head, to the tubesheet shall be equal to (0.6) x
(inside bonnet [or channel] radius - inside nozzle radius). This supersedes TEMA
RCB 9-12.
The velocity head in the inlet nozzle shall not be greater than 15% of the pressure drop in
the tubes, otherwise a conical enlarging/reducing transition shall be provided with an
included angle not exceeding 30 degrees. For TEMA style N or C heads, a straight section
of 200 mm (8 in) minimum length shall be provided at the tubesheet to facilitate peripheral
tube cleaning and/or inspection.
Add new clause:
7.4.5
Channel covers used with clad or weld overlayed channels shall also be clad or weld
overlayed. Loose-lined covers or solid alloy covers shall not be used unless approved by
the Principal.
DEP 31.21.01.30-Gen.
February 2011
Page 19
Add new clause:
7.4.6
Strongbacks shall not be used on flat channel covers to meet deflection limits in TEMA
RCB-9.21.
7.5
FLOATING HEAD
7.5.4
Replace second sentence of this clause by:
Floating heads shall be in accordance with Figure 1 (a) or (b), with full penetration welds
used to connect the flange ring to the dished head.
7.5.5
Add to this clause:
Except for clad or weld overlayed construction, floating head flanges shall be provided with
3 mm (1/8 in) additional thickness to provide a future machining allowance on the gasket
contact seating surface. The additional thickness shall not be used in the calculation of the
maximum allowable working pressure.
Add new clause:
7.5.6
Floating heads shall be through-bolted. Use of bolts which are threaded into tapped holes
in the floating tubesheet is not permitted.
Add new clause:
7.5.7
Divided floating heads shall not be used.
Add new clause:
7.5.8
The backing ring for split ring floating heads shall conform to TEMA Figure RCB 5.141,
style A.
Add new clause:
7.5.9
Integral shell covers shall be used on all sizes of U-tube and multi-tubepass pull-through
floating head exchangers.
Add new clause:
7.5.10
When an axial nozzle is used on the floating head, the minimum distance from the
intersection of the nozzle centreline and the head, to the tubesheet, shall be equal to [(0.6)
x (inside floating head radius - inside nozzle radius)]. This supersedes TEMA R-5.11.
When the tube side inlet nozzle is located at the floating head, the velocity head in the inlet
nozzle shall not be greater than 15% of the pressure drop in the tubes, otherwise the
floating head shall be configured as a conical transition with an included angle not
exceeding 30 degrees.
Add new clause:
7.5.12
Floating head tail-pipes
7.5.12.1 The floating head cover with a tail-pipe and expansion joint shall employ externally
gasketed joints at the external tailpipe spool. The shell cover and tailpipe shall bolt
separately to the external tailpipe spool, such that all gaskets in the flanged design are
accessible from the exterior of the exchanger without removing the tube bundle.
7.5.12.2 The external tail-pipe connections shall be provided with an ASME B16.5 or B16.47 flange
for attachment to the adjoining pipe, except when the tailpipe is connected to another
tailpipe of a stacked exchanger in series. In the latter case, the interconnecting pipe spool
assembly shall be furnished by the Supplier, with all resulting loads (including thermal)
incorporated in the design.
7.5.12.3 Floating head tail-pipes incorporating expansion joints shall be provided with the necessary
lugs on the floating head cover and tail-pipe, and retaining rods (which shall also act as
guide bars). The retaining rods shall be designed for hydrotesting of the bundle outside of
the shell.
DEP 31.21.01.30-Gen.
February 2011
Page 20
7.5.12.4 The Contractor shall specify when an internally bolted connection between the expansion
joint and the floating head cover is required.
7.5.12.5 The Supplier shall provide a tail-pipe and expansion joint drawing with the proposal.
7.6
TUBE BUNDLE
7.6.1
Tubes
7.6.1.1
Add to this clause:
15.9 mm (5/8 in) outside tube diameter may be used only when approved by the Principal.
7.6.1.2
Replace this clause by:
Table 1 below shows the outside tube diameters and minimum required tube gauges for
bare tubes of copper alloys, carbon steel, low alloy steel, aluminium and high alloys. The
actual thickness provided shall be suitable for both internal and external design pressure,
any vacuum conditions, design temperature, tube thinning in U-bends, and any specified
corrosion allowance for the tubes.
TABLE 1
MINIMUM WALL THICKNESS OF TUBES
Tube material
Copper alloys
Carbon steel, low alloy
steels, and
aluminium alloys
High alloys
(defined in ISO 16812)
NOTES:
Nominal
tube outside diameter
mm
15.88
19.05
25.40
31.75
38.10
50.80
15.88
19.05
25.40
31.75
38.10
50.80
15.87
19.05
25.40
31.75
38.10
50.80
(in)
(5/8)
(3/4)
(1)
(1-1/4)
(1-1/2)
(2)
(5/8)
(3/4)
(1)
(1-1/4)
(1-1/2)
(2)
(5/8)
(3/4)
(1)
(1-1/4)
(1-1/2)
(2)
Tube
gauge
(SWG)
16
16
16
14
14
12
14
14
14
14
12
12
16
16
16
14
14
14
Tube wall thickness
(Note 4)
mm
1.63
1.63
1.63
2.03
2.03
2.64
2.03
2.03
2.03
2.03
2.64
2.64
1.63
1.63
1.63
2.03
2.03
2.03
(in)
(0.064)
(0.064)
(0.064)
(0.080)
(0.080)
(0.104)
(0.080)
(0.080)
(0.080)
(0.080)
(0.104)
(0.104)
(0.064)
(0.064)
(0.064)
(0.080)
(0.080)
(0.080)
1. Values in this table are based on Standard Wire Gauge (SWG). Birmingham Wire Gauge (BWG)
may also be selected with the same gauge number. The Standard used shall be specified on the
data/requisition sheet.
2. For special materials (e.g. titanium tubes) the minimum wall thickness shall be 18 SWG.
3. For low fin tubing, the wall thickness shall be at the root diameter. Titanium low-finned tubes shall
have a minimum bare end wall thickness of 16 SWG so that the minimum thickness under the fins
is not less than 0.9 mm.
4. Tubes shall be supplied as minimum wall, except that high alloys (as defined in ISO 16812) may
be supplied as average wall.
7.6.1.3
Add to this clause:
The mean radius of U-bends shall not be less than two (2) times the nominal outside
diameter of the tube in services that are specified on the data/requisition sheet to require
mechanical cleaning on the tube side.
DEP 31.21.01.30-Gen.
February 2011
Page 21
Where 22% Cr grade duplex stainless steel or titanium U-tubes are specified, the minimum
bend radius shall not be less than 3.3 times the nominal outside diameter of the tube,
regardless of whether tubeside mechanical cleaning is required.
7.6.1.4
Add to this clause:
Where the tube thickness is specified as minimum wall, the tube thickness used for thermal
design and pressure drop calculation purposes shall be 1.1 times the minimum wall
thickness.
Add new clause:
7.6.1.4
The tube side pressure drop may be calculated using smooth tube friction factors for
stainless steel and other high alloy tubes, where corrosion is not expected. Commercial
pipe friction factors shall be used for carbon and low alloy steel tubes.
Add new clause:
7.6.1.5
Where possible, the number of tubes in any pass shall not be greater than 10% above or
below the average number of tubes per pass. If this cannot be accommodated, the Supplier
shall indicate this in the proposal. The tube velocity shall be reported on the data/requisition
sheet for each tubepass.
Add new clause:
7.6.1.6
Tubes shall be designed for design pressure on either side, with atmospheric pressure or
vacuum, if specified, on the other side unless otherwise specified or approved by the
purchaser.
Add new clause:
7.6.1.7
Where welded tubes are used, re-dressing or “scarfing” of the weld seam is required when
an expanded only tube-to-tube sheet joint is specified. The Contractor shall specify any
additional testing requirements for welded tubes.
Add new clause:
7.6.1.8
For circumferential low-fin tubes, the fin density shall not exceed 1181 fins per metre
(30 fins per inch). Longitudinally-finned or high-finned tubes shall not be used.
7.6.2
Tubesheets
7.6.2.1
Replace second sentence of this clause by:
Where collar bolts are used, at least four (4) shall be provided and their location shall be
identified on the drawings and by stamped markings on the OD of the tubesheet and on
both ends of the studs. One (1) end of the collar bolt shall be machined with a standard size
hex head.
7.6.2.4
Replace second sentence of this clause by:
Single or two-piece collar type studs shall be supplied for 25% of the bolt holes in the
stationary tubesheet in order to maintain gasket compression load during removal of the
either the bonnet or the shell. The extended portion of the tubesheet shall be designed for
hydrotesting of the shellside or tubeside independently, with the respective bonnet or shell
removed, with the full complement of bolting installed. Removable bundle units with ‘A’ type
heads need not have full diameter tubesheets.
Add new clause:
7.6.2.5
Regardless of the pressure design code that is applied, the tubesheet thickness shall not
be less than that required by either TEMA clause R-7.11 or ASME Section VIII, Div.1 Part
UHX, except where a thin flexible tubesheet design is specified on the data/requisition
sheet.
Add new clause:
7.6.2.6
Stationary tubesheets for removable bundles with bonnet stationary heads shall be
through-bolted. The holes shall not be threaded,
DEP 31.21.01.30-Gen.
February 2011
Page 22
Add new clause:
7.6.2.7
The welded connections between a tubesheet and the adjacent cylinder shall be in
accordance with ASME Code Figure UW-13.3, Type (a) (b) or (c) or equivalent
configurations. Figure UW-13.2 Type (a), (b), (c), (i), (j), (k), or equivalent, may only be
used in non-cyclic service where the design pressure is less than 6.9 MPag (1000 psig) and
the design temperature is less than 400°C (750°F).
Add new clause:
7.6.2.8
Tubesheets with applied cladding (or weld overlay) shall meet the following requirements:
•
The cladding shall be integrally and continuously bonded to the base material.
Brazing shall not be used to bond the cladding to the tubesheet.
•
Integrally clad tubesheets and tubesheets with applied weld overlay shall be
ultrasonically tested to check the integrity of the bonding in accordance with ASTM
A 578, with an acceptance level of S7.
Add new clause:
7.6.2.9
Except for clad or weld overlayed construction, gasketed tubesheets shall be provided with
3 mm (1/8 in) additional thickness to provide a future machining allowance on all gasket
contact seating surfaces (including the pass partition). The additional base material
thickness shall not be used in the calculation of the maximum allowable working pressure.
7.6.3
Transverse baffles and support plates
7.6.3.1
Add to this clause:
For titanium tubes, the baffle/support plates shall have a thickness in accordance with
TEMA; however, the minimum thickness shall not be less than 5 mm (3/16 in).
7.6.3.2
Replace this clause by:
To facilitate draining of heat exchanger shells, all transverse baffles and support plates,
which extend to the bottom of the shell, shall have V-notches that are 10 mm (3/8 in) high
for shell inside diameters of 1000 mm (40 in) or less. For larger shell diameters, the Vnotches shall be 16 mm (5/8 in) high and 19 mm (3/4 in) wide at the lowest point.
Add new clause:
7.6.3.4
The unsupported tube span shall not exceed 80% of the value indicated in TEMA Table
RCB-4.52, except that it shall not exceed 60% in the following cases:
•
For titanium tubes and applications with similar tube wall thickness and elastic
modulus combinations;
•
For tubes in kettle-type reboilers, evaporators, and steam generators.
Add new clause:
7.6.3.5
A reduction in the baffle to shell diametric clearances given in TEMA Table RCB-4.3 may
be considered in some cases to reduce leakage between the baffles and shell, with
approval of the Principal. In such cases the Supplier shall verify that the reduced clearance
is possible considering fabrication tolerances, bundle insertion, etc.
Add new clause:
7.6.3.6
When a full support baffle at the tangent line of U-bends is specified on the data/requisition
sheet, the full support shall have cut-outs to allow fluid circulation through the U-bend area
(i.e. the support shall be cut above the top tube row and a cut-out provided below the
bottom tube row). These cuts shall not be located at tube centrelines (i.e. the tubes must be
fully supported).
DEP 31.21.01.30-Gen.
February 2011
Page 23
Add new clause:
7.6.3.7
A full support baffle shall be provided at the shell inlet/exit nozzles for TEMA shell types
"H", "G", and “X” and at the central nozzle for TEMA shell type "J". The baffle shall be
located at the nozzle centre-line.
Add new clause:
7.6.3.8
Floating heads in shells with removable shell covers shall be supported by a doughnut
baffle with a thickness that is 3 mm (1/8 in) larger than the tube support baffles. Unless
otherwise required for anchoring seal strips, a doughnut baffle shall not be provided in
shells with integral shell covers.
Add new clause:
7.6.3.9
Where vertically cut transverse baffles (either single or double segmental) are used in
combination with vertically oriented nozzles, a partial tube support which fully covers a
minimum of four (4) tube rows shall be provided, unless the vibration analysis dictates that
a larger number of rows must be supported. The partial support shall be located at the
nozzle centreline at the entrance or exit of the shell, and is required in addition to any
impingement protection. The partial support shall not cause excessive flow restriction in the
end baffle space.
Add new clause:
7.6.3.10 Unless otherwise specified on the data/requisition sheet, vertical cut double segmental
baffle designs shall consist of an even number of cross-passes, with the centre baffle type
installed as the first and last baffle. As an alternative to installation of partial supports per
clause 7.6.3.9, the centre baffles may be located at the shell inlet and outlet nozzle
centrelines to reduce the length of the unsupported tube span in the window area. In this
case, the centre baffles shall be configured to support all tubes in a minimum of 4 rows
located adjacent to the shell inlet and outlet nozzles, unless the vibration analysis dictates
that a larger number of rows must be supported.
Add new clause:
7.6.3.11 When positioning tie rods/spacers in bundles with no tubes in window baffles, the maximum
unsupported span of tie-rods in the window area shall not exceed 80% of the maximum
values in TEMA table RCB-4.52 based on tie-rod diameter. This may require a continuous
ring to be provided on the baffles/intermediate supports.
Add new clause:
7.6.3.12 Standard tube holes in all transverse baffle and full support plates shall have a diameter
0.4 mm (1/64 in) over the outside diameter of the tubes.
Add new clause:
7.6.3.13 If one (1) or more detuning baffles (installed parallel to the direction of flow) are required to
change the acoustic frequency, the location, length, and height of the detuning baffle(s)
shall be approved by the Principal.
Add new clause:
7.6.3.14 Other types of supports such as wires, bands, strip baffles, etc., require approval of the
Principal.
Add new clause:
7.6.3.15 The free end of each tie rod shall be fitted with double nuts. The nuts shall be tack-welded
together.
7.6.4.
Impingement protection
7.6.4.1
Add to this clause:
Impingement protection shall be provided when required by TEMA paragraph RCB-4.6 or
when specified on the data/requisition sheet. Heat exchangers with vapour or steam
DEP 31.21.01.30-Gen.
February 2011
Page 24
(superheated, saturated or wet) as the heating medium on the shell side shall always have
impingement protection.
7.6.4.2
Replace this clause by:
Impact plates shall be equal in diameter to the inlet nozzle bore plus 50 mm (2 in), or 20%
larger than the inside diameter of the inlet nozzle, whichever is greater. Impact plates shall
not be used when the diameter of the plate exceeds 50% of the inlet baffle spacing.
7.6.4.3
Replace this clause by:
The shell entrance and bundle entrance areas (as defined by TEMA) shall not be less than
the flow area of the of the inlet nozzle. The velocity at the periphery of an impingement
plate, moving horizontally or vertically, shall not be greater than the velocity in the inlet
nozzle.
7.6.4.5
Replace this clause by:
At least two (2) tie rods/spacers shall be used to support an impingement plate. The
clearance between the impingement plate and the top row of tubes shall not be less than
3 mm (1/8 in). Where an impingement plate is specified with nozzle diameters of DN 400
(NPS 16) or higher, three (3) tie rods/spacers shall be used for support.
Add new clause:
7.6.4.7
A 13 mm (1/2 in) diameter drain hole shall be provided in impingement plates that are
welded to the shell if the plate prevents complete draining of the shell contents.
Add new clause:
7.6.4.8
Impingement rods SHALL [PS] be used in the following cases:
•
when an impingement plate diameter would be equal to, or greater than, 50% of
the inlet baffle spacing;
•
with a No Tubes-in-Window (NTIW) baffle design;
•
when vibration at the bundle entrance and exit area is problematic with an
impingement plate.
Add new clause:
7.6.4.9
Impingement rods shall be used when the inlet baffle spacing is 10% or more of the
effective tube length and the shell side fluid heat transfer resistance is equal to or greater
than 35% of the total resistance.
Add new clause:
7.6.4.10 When impingement rods are used:
•
They shall be supplied as solid bars, unless otherwise approved by the Principal.
•
For E, J21, and F shells, one (1) end of the impingement rods shall be threaded for
connection to tapped holes in the tubesheet. Alternately, the impingement rods
may be counter-sunk into holes drilled in the tubesheet and fillet welded around the
full diameter.
•
The rods shall extend from the tubesheet, the rear end support plate (when the
inlet nozzle is located at the floating head or U-bend), to the adjacent baffle. For G,
H, J12, and X shells, impingement rods shall extend from the support baffle(s)
located at the inlet nozzle centerline(s) to adjacent support baffles.
•
The length and width of impingement rod array (based on the centreline of the
outermost rods) shall be at least 50 mm (2 in.) or 20% larger than the inside
diameter of the inlet nozzle, whichever is greater.
•
at least two (2) rows of rods are required, laid out on an angle of 30, or 45 degrees
conforming to Table 2.
DEP 31.21.01.30-Gen.
February 2011
Page 25
TABLE 2
IMPINGEMENT ROD LAYOUT
Tube lay-out
angle
(degrees)
Rod lay-out
angle
(degrees)
30, 60, 90
45
30
45
Rod pitch
mm (in)
25 (1 in)
32 (1.25 in)
For 19 (¾ in) tubes
For ≥ 25 mm (1 in) tubes
Rod diameter (mm)
16 (5/8 in)
19 (3/4 in)
19 (3/4 in)
25 (1 in)
Add new clause:
7.6.4.10 Where a full or partial circumferential distributor belt is specified at the inlet, the distributor
belt shall be attached to the OD of the shell with the inlet nozzle mounted on the distributor.
The nozzle shall be located such that flow impinges on the shell OD and is diverted to a
cut-out window in the shell for bundle entrance. The velocity in the annular space between
the ID of the distributor and the OD of the shell shall not exceed the velocity in the nozzle or
a value of ρv2 of 2240 kg/m2-s (1500 lb/ft2-sec). The velocity in the cut-out windows should
not produce a value of ρv2 greater than 150 kg/m2-s (100 lb/ft2-sec).
Add new clause:
7.6.4.11 Where a domed inlet nozzle is specified, an impact plate with a diameter not less than the
nozzle bore plus 50 mm (2 in) shall be provided at the upper extremity of the enlargement's
ID. The impingement plate shall be located at least one dome diameter from the nearest
tube or tie rod. The cross sectional area of the enlargement (dome) shall not be less than
four (4) times the cross sectional area of the nozzle and shall not produce a value of ρv2
greater than 150 kg/m2 s (100 lb/ft2-sec). The flow area between the OD of the impact plate
and ID of the dome shall not produce a value of ρv2 in excess of 2240 kg/m2-s
(1500 lb/ft2-sec). The combined pressure drop in the distributor and bundle shall be at least
2/3 of the total pressure drop for the exchanger.
Add new clause:
7.6.4.12 Perforated plates may only be considered in cross flow exchangers (X-shells) to provide
fluid distribution over the entire bundle length, and requires approval by the Principal. When
perforated plates are specified on the data/requisition sheet, the perforations shall be a
minimum of 20% of the plate area.
7.6.5
Bypass sealing devices
7.6.5.1
Replace this clause by:
Bypass sealing devices (such as flat seal strips, dummy tubes, or tie rods) shall be
provided for all shell and tube exchangers that are not in isothermal condensing or boiling
service on the shellside. Bypass sealing devices shall be located in the peripheral bypass
lanes and in the bypass lanes between tube passes when pass partition lanes are not
parallel to the baffle cut, whenever the width of the bypass lane exceeds twice the
clearance between tubes. Bypass sealing devices shall be of equivalent material to the
transverse baffles. The number of seals in each bypass lane shall be determined as
follows, unless the data/requisition sheet specifies otherwise:
7.6.5.5
•
When the distance between baffle-cut edges is six (6) tube pitches or less, two (2)
seals shall be provided.
•
When the distance between baffle-cut edges exceeds six (6) tube pitches, multiple
seals shall be provided every four (4) to six (6) tube pitches between the baffle
cuts.
•
The first and last seals shall be placed at one (1) tube pitch or 32 mm (1.25 in),
whichever is smaller, from the baffle cut line.
Replace this clause by:
The nominal thickness of seal strips shall be as follows:
DEP 31.21.01.30-Gen.
February 2011
Page 26
•
for removable bundles; the nominal baffle thickness or 6 mm (1/4 in), whichever is
greater;
•
for fixed tubesheet exchangers; the nominal baffle thickness or 6 mm (1/4 in),
whichever is less.
Add new clause:
7.6.5.9
Sealing devices shall normally be continuously welded or bolted to the stationary
tubesheet. Tubesheet materials that are non-weldable or that require post weld heat
treatment shall have the sealing devices attached by bolts or studs.
In floating head exchangers, with more than 10% of the net heat transfer surface in the
baffle spaces adjacent to the tubesheets and in all TEMA “X” type shells, the sealing
devices shall also extend to within approximately 50 mm (2 in) of the floating tubesheet.
When the sealing devices are extended to the floating tubesheet, a cut-out ring (located
near the floating tubesheet) shall be provided to anchor the sealing devices. The presence
of seal strips shall be considered in the calculation of bundle entrance and exit flow areas.
When the baffle cut is parallel to the centre-line of the inlet and/or outlet nozzle, peripheral
seal strips shall not be extended through the inlet and outlet baffle spaces. In this case,
seal strips shall be welded to the first and last baffles.
7.6.6
Bundle skid bars
7.6.6.1
Replace this clause by:
For all removable bundles with a mass of more than 5450 kg (weight of 12 000 lb), or for
TEMA “F”, “G”, and “H” type shells with removable U-tube bundles with welded-in
longitudinal baffles, a continuous sliding surface shall be provided to facilitate bundle
removal. For all TEMA F, G, and H type shells with removable U-tube bundles and weldedin longitudinal baffles, skid bars shall be provided on the bottom and top halves of the
bundle. The requirement for skid bars in the top-half of the bundle may require additional
space in the tube layout.
7.6.6.2
Add to this clause:
f) Skid bars shall be connected to the stationary tubesheet;
g) Skid bars strips shall not obstruct the tube lanes or pass partition lanes for tube patterns
of 45 and 90 degrees (or hinder the liquid flow to the centre tube rows in a kettle-type
reboiler);
h) Slots shall be cut in skid bars when located under the inlet or outlet nozzles to prevent
blocking of the entrance or exit regions. Overlapping of sliding strips outside of the
nozzle areas should be applied as applicable to account for slots.
Add new clause:
7.6.6.3
For removable bundles units with an unsupported tube span of 760 mm (30 in) or and
higher (based on central baffle spacing), and for all vertical exchangers with removable
bundles, a minimum of four (4) skid bars shall be provided, evenly divided around the
circumference of the bundle. The minimum required size of the skid bars is shown below in
Table 3. Sealing strips, if utilized in the bundle design to minimize bypassing, can satisfy
the requirements of this paragraph provided the sealing strips meet the dimensions shown
in Table 3.
DEP 31.21.01.30-Gen.
February 2011
Page 27
TABLE 3
MINIMUM SLIDING STRIP SIZE
Skid bar dimensions (minimum)
Shell Inside Diameter
mm
150 – 380
381 – 690
691 – 840
841 – 1220
1221 – 1530
1531 – 2540
in
6 – 15
16 – 27
28 – 33
34 – 48
49 – 60
61 – 100
Height
mm
25
40
50
60
75
75
Thickness
in.
1.0
1.5
2.0
2.5
3.0
3.0
mm
6
10
12
12
15
19
in
1/4
3/8
1/2
1/2
5/8
3/4
Add new clause:
7.6.6.4
A tube bundle guide shall be provided for all single tube-pass pull-through bundles with
tailpipe bellows and integral shell covers to ensure proper positioning of the floating head
with respect to the shell and proper orientation of the tailpipe flange and mating shell
flange.
Add new clause:
7.6.6.5
When provided, tube bundle guides shall be a bar or inverted angle welded to the bottom of
the shell, with accommodating notches in the baffles, floating tubesheet, and floating head.
Guides shall not extend over the inlet or outlet shellside nozzle. It shall extend beyond the
floating head in the shell to preclude hang-up of the floating tubesheet during bundle
removal. All notches in floating tubesheets and floating head covers shall have rounded
corners to prevent stress risers.
7.6.7
Tube-to-tubesheet joint
Add new clause
7.6.7.1
The Contractor shall specify the type of tube-to-tubesheet joint on the data/requisition
sheet.
Add new clause:
7.6.7.2
For tube-to-tubesheet joints specified as expanded only, there shall be two (2) grooves in
accordance with TEMA.
For tubesheets with applied cladding or weld overlay on the tubeside of the tubesheet, a
groove shall not be applied in the cladding (or weld overlay) to provide a seal. The tubes
shall be strength-welded to the cladding (or weld overlay).
Explosive bonding and/or explosive expanding may only be used when approved by the
Principal.
Add new clause:
7.6.8
Tube pitch and layout
7.6.8.1
There shall be at least two (2) tube rows per pass.
7.6.8.2
The minimum tube pitch shall be in accordance wth Table 4.
DEP 31.21.01.30-Gen.
February 2011
Page 28
TABLE 4
MINIMUM TUBE PITCH
Tube OD
[NOTE]
Tube
Gauge
Pitch (Expanded Only)
Pitch (Strength-Welded)
30° or 60°
45° or 90°
30° or 60°
45° or 90°
mm (in)
SWG
mm (in)
mm (in)
mm (in)
mm (in)
15.9 (5/8)
16
19.8 (0.7813)
22.2 (0.875)
22.2 (0.875)
22.2 (0.875)
15.9 (5/8)
14
20.6 (0.8125)
22.2 (0.875)
22.2 (0.875)
22.2 (0.875)
19.1 (3/4)
16
23.8 (0.9375)
25.4 (1.0)
25.4 (1.0)
25.4 (1.0)
19.1 (3/4)
14
23.8 (0.9375)
25.4 (1.0)
25.4 (1.0)
25.4 (1.0)
19.1 (3/4)
12
25.4 (1.0)
25.4 (1.0)
25.4 (1.0)
25.4 (1.0)
19.1 (3/4)
10
-
-
27.0 (1.0625)
27.0 (1.0625)
25.4 (1.0)
16
31.8 (1.25)
31.8 (1.25)
31.8 (1.25)
31.8 (1.25)
25.4 (1.0)
14
31.8 (1.25)
31.8 (1.25)
31.8 (1.25)
31.8 (1.25)
25.4 (1.0)
12
31.8 (1.25)
31.8 (1.25)
31.8 (1.25)
31.8 (1.25)
25.4 (1.0)
10
31.8 (1.25)
31.8 (1.25)
33.3 (1.3125)
33.3 (1.3125)
25.4 (1.0)
8
-
-
33.3 (1.3125)
33.3 (1.3125)
NOTE:
For tubes with an outside diameter of 31.8 mm (1.25 in) and larger, the minimum pitch shall be 1.25
times the tube OD.
7.6.8.3
The tube lay-out shall ensure that the allowable stresses in the tubes due to temperature
differences between tubes in adjacent passes are not exceeded.
7.6.8.4
The arrangement of the tube passes (ribbon vs. quadrant) shall be chosen to minimize the
number of pass partition lanes perpendicular to the baffle cut and to promote free draining
and venting of the channel. When cooling viscous shell side fluids (ratio of the viscosity at
the wall temperature to the bulk temperature is three (3) or more), the tube passes shall be
arranged to provide a uniform wall temperature along any plane parallel to the baffle cut to
minimize mal-distribution.
7.6.8.5
When the tube side temperature range is greater than 83°C (150°F), the tube passes shall
be arranged as ribbon flow, to minimize thermally induced stresses in the bonnet (or
channel) and tubesheet.
Add new clause:
7.6.9
Longitudinal baffles
7.6.9.1
Longitudinal baffles shall be continuously welded to the shell, except for non-baffled G or H
shell reboiler service. Longitudinal baffles shall also be welded to the tubesheet of a fixedtubesheet exchanger when a seal is required. U-tube bundles specified with longitudinal
baffles require four (4) or more tubepasses with the U-bends arranged in the horizontal
plane to permit installation and removal of the bundle. U-tube bundle tubesheets shall
include a longitudinal baffle partition groove and gasket on the shell side of the tubesheet.
The use of flexible spring seal sets with longitudinal baffles may only be used when
approved by the Principal. In such cases, a Kempchen Style T4 Seal, or equivalent, shall
be used.
7.6.9.2
Thermal leakage across the longitudinal baffle shall be considered in the thermal design
calculations.
7.6.9.3
The minimum thickness for longitudinal baffles shall be the thickness calculated per TEMA
RCB-9-132, using twice the calculated clean shellside pressure drop, plus twice the
shellside corrosion allowance or the minimum thickness allowed by TEMA, whichever is
greater.
DEP 31.21.01.30-Gen.
February 2011
Page 29
7.6.9.4
For U-tube bundles with welded longitudinal baffles, a warning plate shall be provided that
states the following:
“Tube bundle requires special handling during installation and removal. Refer to the
Manufacturer’s tube bundle drawings for details.”
Add new clause:
7.6.10
Tie rods and spacers
Tie rods and spacers shall be in accordance with Table 5. The tie rods and spacers shall be
evenly distributed around the circumference of the baffles. Additional tie rods may be
required near the centre of the bundle. Spacers shall not be used if there is a hazardous
fluid (H2, H2S, HCN, etc.) on the shell side.
TABLE 5
TIE ROD STANDARDS
Nominal shell diameter
mm
132 - 393
394 - 698
699 - 850
851 - 1231
1232 - 1537
1538 - 2540
NOTES:
(in)
(6-15)
(16-27)
(28-33)
(34-48)
(49-60)
(61-100)
Tube OD of 19.05 mm
(3/4 in) and less
Solid Rod
Spacer Pipe
minimum
OD
diameter
(sch 80)
mm
mm
12
17.15
15
17.15
15
17.15
15
17.15
19
21.34
19
21.34
Tube OD of 25.4 mm
(1 in) and larger
Solid Rod
Spacer Pipe
minimum
OD
diameter
(sch 80)
mm
mm
12
17.15
15
17.15
19
21.34
19
21.34
22
26.67
22
26.67
Minimum
number of
tie rods
4
6
6
8
10
12
1. The baffles shall be supported by solid rods welded to the baffles or by spacer pipes, keeping the
baffles at distance, with supporting rods inside.
2. The screw thread connection of the tie rod in the tubesheet shall have a diameter that is equal to,
or slightly smaller than, the diameter of the tie rod.
7.7
NOZZLES AND OTHER CONNECTIONS
7.7.1
Replace this clause by:
All connections shall be flanged with through bolting. Unless specified otherwise, flanges
shall be raised face with a surface finish of 125 to 250 AARH. Threaded or socket-welded
connections shall not be used. Butt-weld ends, ring joint flanges, or proprietary designs
(e.g. self-energizing seal ring and hub with clamped connectors) may only be used when
specified or approved by the Principal.
7.7.3
Replace this clause by:
The minimum nozzle size, including vents, drains and all other auxiliary connections shall
be DN 40 (NPS 1½). In addition the following requirements apply:
a) For vertical fixed tube sheet exchangers in low fouling shell side service (0.00034 m2K/W or less), a tubesheet vent and drain shall be provided consisting of a 25 mm (1 in.)
long weld neck flange, with blind, welded to the edge of the tube sheet. The tubesheet
vent and drain holes shall be 16 mm (5/8 in.) minimum diameter and be parallel to the
tubes to the mid-thickness of the tubesheet and then run radially outward to the edge of
the tubesheet. The vent shall be located on the opposite side of the shell compared to
the shell side nozzle adjacent to the upper tubesheet. When the tubesheet thickness
does not permit the 16 mm (5/8 in) drain hole and/or the 25 mm (1 in.) long welding
neck, a smaller size drain and/or welding neck flange consistent with the physical
limitations may be used;
b) For vertical fixed tube sheet exchangers in fouling shell side services (0.00035 m2-K/W
or higher), a long weld neck vent and drain, in accordance with Table 6, shall located
as close to the tubesheets as possible.
DEP 31.21.01.30-Gen.
February 2011
Page 30
c) Other than tubesheet vent and drain connections, the minimum size for vent and drain
connections on heat exchangers shall be in accordance with Table 6.
TABLE 6
MINIMUM VENT AND DRAIN CONNECTION SIZES
Nominal Shell Diameter
mm
in
150 - 500
6 - 20
≥ 500
≥ 20
NOTES:
DN
mm
40
50
NPS
in
1½
2
1. If a vent or drain connection will be used as cleaning connection the minimum connection size
shall be DN 50 (2 NPS).
2. All vent and drain connections shall be flanged and provided with a permanent blind flange, with
the full complement of bolting and service gaskets installed, unless otherwise noted in the
data/requisition sheets.
3. Vents and drains shall not be provided on any intermediate nozzle between stacked exchangers in
series.
7.7.4
Replace this clause by:
Only forged weld-neck or long weld-neck flanges shall be used. Use of slip-on and lap joint
flange types may be considered under the restrictions in DEP 31.22.20.31-Gen, but require
approval by the Principal.
7.7.6
Replace this clause by:
The projection of flanged connections shall permit removal of the bolting from the
exchanger side of the flange, without removing shell or channel insulation. For exchangers
stacked in series, this requirement need only be applied to the inter-connecting nozzles of
the lower shell.
7.7.8
Replace this clause by:
There shall be no temperature, pressure gauge, or cleaning connections located on heat
exchanger nozzles, except for direct interconnection nozzles of stacked exchangers when
specified on the datasheet.
7.7.9
Replace this clause by:
The design of connections shall be suitable to withstand the forces and moments specified
in Annex VIII of DEP 31.22.20.31-Gen.
Add new clause:
7.7.10
Unless otherwise specified, flanges DN 50 (NPS 2) and smaller, and flanges for all
safety/relief valve nozzles connected to heat exchanger shells, shall have a minimum rating
of ASME Class 300.
Add new clause:
7.7.11
Packed floating head nozzles and packing boxes shall not be used.
Add new clause:
7.7.12
A manway shall be provided in the shell cover of kettle reboilers or kettle steam generators
when the vapour outlet nozzle has a demister and the nominal diameter of the removable
tube bundle is less 610 mm (24 in). Manways shall be included for other kettle designs,
when specified on the data/requisition sheet by the Contractor.
Add new clause:
7.7.13
Permissible types of weld attachments for set-through nozzles are shown in ASME Code,
Figures UW-16.1(c) without backing strip, (d), (e), (f-1) through (f-4), and (g), or equivalent.
Set-on nozzles, in accordance with ASME Code, Figure UW-16.1(a) or equivalent, may be
used only if the additional requirements in DEP 31.22.20.31-Gen are met.
Add new clause:
DEP 31.21.01.30-Gen.
February 2011
Page 31
7.7.14
Nozzle necks shall be seamless pipe with flange bore matching the pipe bore. For nozzle
necks greater than DN 600 (NPS 24), rolled plate may be substituted provided that the
longitudinal seam is subjected to 100% radiography.
Add new clause:
7.7.15
Nozzles on clad exchangers shall utilize clad or weld overlay construction. The raised face
shall be machined to allow a minimum of 5 mm (3/16 in) weld overlay to be applied.
Surface finish shall be in accordance with ASME 16.5. Dis-similar metal welds between
flanges, nozzle necks, and the shell or channel to which they are welded shall not be used,
unless approved by the Principal.
Add new clause:
7.7.16
Blind flanges and manway covers on clad or weld overlayed nozzles shall also be clad or
weld overlayed. Lined covers shall not be used, unless approved by the Principal.
Add new clause:
7.7.17
Vents and drains with blind flanges shall be provided at the highest and lowest points on
both channel and shell side, if complete venting and draining cannot be accomplished
through the inlet or outlet nozzles.
Add new clause:
7.7.18
The interconnecting nozzles of stacked exchangers shall be located to limit the distance
between the shell and tubeside nozzles. When the tube side interconnecting nozzles are at
the front end, the shell side connections of E-shells shall be located adjacent to the
stationary tubesheet. Other arrangements (such as G and J shells) shall be investigated for
the resultant stress due to differential axial thermal growth between shells.
Add new clause:
7.7.19
Non-condensable vents shall be provided on all exchangers that condense steam. The
vents shall be located in the vapour space at the end of the flow path. Two (2) vent
connections shall be provided on all vertical exchangers condensing steam on the shell
side. One (1) shall be located opposite the vapour nozzle and designed to purge the
underside of the tubesheet. The second vent is intended for operational purposes and shall
be located below the second transverse baffle from the bottom of the exchanger.
7.8
FLANGED EXTERNAL GIRTH JOINTS
7.8.1
Add to this clause:
Studded-in flange designs may be considered only in TEMA D type or “pill box” type high
pressure closure channel designs, with the approval of the Principal. Breech-lock closures
shall not be used without the approval of the Principal.
7.8.2
Replace this clause by:
Flanges for external girth joints shall be of the forged welding neck type. Forged slip-on
flanges shall not be used unless approved by the Principal.
7.8.3
Replace this clause by:
Nubbins are not permitted on flanges for any gasket type. In addition, the alternate tongue
and groove joint arrangement shown in TEMA Figure F-3 shall not be used.
7.8.4
Replace first sentence of this clause by:
The clearance between flanges or flange and tubesheet after assembly shall not be less
than 4.8 mm (3/16 in) at the periphery of the flanged joint.
7.8.6
Add to this clause:
Through-hardened washers shall be supplied as ASTM F436 and in accordance with
ASME PCC-1-2010, Appendix M.
7.8.7
Replace this clause by:
DEP 31.21.01.30-Gen.
February 2011
Page 32
Hydraulic bolt tensioning shall be applied if any of the following conditions in Table 7 apply.
TABLE 7
BOLT-TENSIONING REQUIREMENTS
SERVICE
ASME
RATING
CLASSES
BOLT
DIAMETER
in
All
All
≥2
All
≥ 1500
≥1½
Hydrogen
≥ 600
≥1½
Very toxic service
All
All
Large temperature gradient,
intermittent service, cyclic service
(when specified by the Contractor)
[1]
All
All
[2]
Notes:
1. Tube side temperature range greater than 110°C (200°F) during steady state operation, or
exchangers with a rapid shell or tube side temperature change (greater than 110°C [200°F]
change within 5 minutes). The Contractor shall specify on the data/requisition sheet when there is
a rapid temperature change because of either cyclic service or temperature shock associated with
exchangers in intermittent service.
2. For bolting diameters less than 1-1/2 in, other methods of specialized bolt tightening (e.g.
hydraulic torquing in combination with ultrasonic extensiometer measurement) may be considered
in lieu of bolt tensioning, when approved by the Principal. Bolting ends shall be machined true and
smooth to accommodate the use of ultrasonic extensiometer measurements
When bolt tensioning is applied, the bolting shall have adequate clearance and additional
thread length protruding from the hexagonal nut at one (1) end as per Standard Drawing
S 10.071, and shall be fitted with anti-corrosion caps after final assembly.
Add new clause:
7.8.10
Except for clad or weld overlayed construction, external girth flanges shall be provided with
3 mm (1/8 in) additional thickness to provide a future machining allowance on the gasket
contact seating surface. The additional thickness shall not be used in the calculation of the
maximum allowable working pressure.
Add new clause:
7.8.11
Clad or weld overlayed ferritic steel flanges shall not be used with solid alloy shells or
channels, and solid alloy flanges shall not be used on clad or weld overlayed ferritic shells
or channels (i.e. dis-similar metal welds between flanges or integral tubesheets and the
cylinders to which they are welded is not permitted), without review and approval of the
Principal.
Add new clause:
7.8.12
Flanged joint design
Flange design requirements and additional calculations required to verify the gasket and
bolt stresses at the design pressure are provided below. These procedures shall be used
whenever A 193-B7, B7M, L7, L7M or B16 bolting material is utilized. If other bolting
materials are specified, the Principal shall be consulted for guidance.
7.8.12.1 The Supplier shall design all external girth flanges and floating head flanges to ASME
Section VIII, Division 1, Appendix 2. The design stress values used for calculating all
external girth flanges, floating head flanges, channel covers, and tubesheets extended as
flanges shall be 88% of the allowable stress in ASME Section II, Part D, Table 1A.
DEP 31.21.01.30-Gen.
February 2011
Page 33
7.8.12.2 Application of the ASME Code flange rigidity index calculation, based on design pressure
and not MAWP, shall be utilized for all external girth flanges and floating head flanges. The
rigidity index shall not exceed 1.0, with the following exceptions:
•
For flanges on shells with less than 610 mm (24 in) nominal diameter and design
pressures less than 2760 kPag (400 psig), the rigidity index shall not exceed 0.7.
•
For hydrogen service, the rigidity index shall not exceed 0.7.
7.8.12.3 Where serrated or grooved metal gaskets with graphite, PTFE, or other non-asbestos
facing are used, the values of m and y, as defined in the ASME code, shall not be less than
3.75 and 52.4 MPa (7600 psi) respectively.
7.8.12.4 The gasket pass partition rib area shall be added to the peripheral gasket area for the
purposes of determining the required bolt loads (e.g. Wm1 and Wm2 in ASME).
7.8.12.5 All bolts shall straddle both the horizontal and vertical centrelines [i.e. the number of bolts
shall be a multiple of four(4)].
7.8.12.6 Upon completion of the flange design, the Vender shall determine the target assembly bolt
stress and gasket seating stresses in accordance with the procedure specified in ASME
PCC-1-2010, Appendix O. For the purposes applying Appendix O, the following shall be
applied:
a)
The minimum and maximum permissible bolt stress values shall be in accordance
with Table 8;
b)
The minimum gasket seating stress, the minimum gasket operating stress, and the
maximum permissable gasket stress shall be in accordance with Table 9;
c)
Gasket relaxation fraction shall be 0.7, unless otherwise specified;
d)
Calculations shall be based on the full contact width of the gasket at the design
pressure. The total gasket pass partition rib area shall also be included in this
calculation.
When gaskets are present on both sides of a tubesheet, the Vender shall determine the
bolt stress required to achieve the minimum specified gasket operating stress for each
gasket. The higher of the two (2) bolt stresses shall be used, provided that the resulting
gasket stress does not exceed the value in Table 9 and the bolting stress does not exceed
the value in Table 8.
If the required gasket stresses cannot be achieved within these constraints, the flanged
joint shall be re-designed accordingly.
This shall be demonstrated by calculation and submitted for approval.
TABLE 8
PERMISSABLE BOLT STRESS [NOTE]
MPa
psi
Minimum
345
276 [NOTE]
50 000
40 000 [NOTE]
Maximum
483
414 [NOTE]
70 000
60 000 [NOTE]
NOTE:
For A 193 B7/B7M, L7/L7M, and B16 bolting. The lower stresses shall be applied for B7M and L7M
grade bolting.
DEP 31.21.01.30-Gen.
February 2011
Page 34
TABLE 9
GASKET STRESS REQUIREMENTS [NOTE]
Minimum gasket seating stress
Maximum permissable gasket
stress
Minimum gasket operating
stress
Note:
MPa
psi
138
20 000
240
35 000
103
15 000
These values apply for spiral wound, serrated or grooved metal gaskets, and double jacketed gaskets.
7.9
EXPANSION JOINTS
7.9.1
Replace this clause by:
Where an external expansion joint is required on the shell of a fixed tubesheet exchanger, it
shall be the flanged and flued type with the same materials as the shell. Flanged and flued
expansion joints shall comply with the requirements of TEMA, ASME Code Section VIII,
Div.1 UHX-17 and Appendix 5.
The Supplier shall advise in the proposal if the conditions provided for the exchanger
design are too severe for a single flanged and flued type expansion joint.
The use of two (2) flanged and flued type expansion joints, or a thin-wall bellows expansion
joint on the shell, requires approval of the Principal. An external thin-wall bellows expansion
joint SHALL [PS] not be used on the shell, when the shell side is designated as hydrogen
service, very toxic service, wet H2S service, or when handling hydrocarbons above their
auto-ignition temperature.
Where an internal expansion joint is required with the tail-pipe nozzle of a single pass
floating head exchanger, the flanged and flued type or thin-wall bellows type may be used.
The exchanger design and placement of the expansion joint shall be such that it is located
at the smaller nozzle and/or the cold end of the heat exchanger.
7.9.2
c) Replace this clause by:
Thin-wall bellows shall be designed to the ASME Code Section VIII, Div.1 UHX-16 and
Appendix 26. The cycle life as calculated by the Standards of the Expansion Joint
Manufacturers Association (EJMA) shall not be less than 1000 normal operating cycles.
Bellows which are annealed after forming shall be calculated with the membrane and
meridional stresses due to pressure (S1 through S4) multiplied by a factor of 2, to
compensate for the loss of cold work strength.
e) Replace this clause by:
Bellows shall be formed from a cylinder with longitudinal weld seams only.
Circumferential welds are not permitted. The longitudinal weld seam in the bellows
cylinder shall be 100% liquid penetrant examined on both sides after forming. In
services with operating temperatures above 425°C (800°F), the longitudinal seam shall
be 100% radiographed prior to forming and 100% liquid penetrant examined on both
sides after forming. The bellows to pipe attachment welds shall also be liquid penetrant
examined. The Principal shall approve the details of expansion joint design, fabrication,
inspection and testing.
Add new clauses:
h) Where a design with an external bellows type expansion joint on the shell cannot be
avoided, a two-ply bellows shall be used, with each ply designed for the design
pressure. Single-ply bellows shall be used for internal bellows, unless otherwise
specified by the Principal.
DEP 31.21.01.30-Gen.
February 2011
Page 35
i) External protective covers shall be of bolted construction, to permit removal and
inspection of the bellows.
j) Unless otherwise specified on the data/requisition sheet, the bellows material shall be
Alloy 625 LCF. The supplier of the bellows type expansion joint shall be approved by the
Principal.
k) Thin-wall bellows shall not be subjected to any additional heat treatment other than that
performed by the bellows supplier. When additional heat treatment cannot be avoided,
the details of the proposed construction and heat treatment procedure shall be approved
by the Principal.
Add new clause:
7.9.3
The minimum no. of cycles used in ASME code calculations for flanged and flued or
bellows type expansion joints shall be 500 normal operating cycles. The minimum no. of
cycles considered for each upset case (e.g. start-up, power failure, loss of wash water, tube
side steam-out, etc.) shall be specified by the Contractor.
7.10
GASKETS
7.10.1
Replace this clause by:
The gasket type and gasket materials for external girth flanges and floating head flanges
shall be specified by the Contractor on the data/requisition sheet.
Acceptable gasket types for hydrocarbon and steam services are spiral wound graphitefilled, and serrated or grooved metal graphite-covered (also known as kammprofile). For
hydrogen service, gaskets shall be spiral wound graphite-filled or serrated metal graphitecovered type.
Metal-reinforced exfoliated graphite sheet gaskets may be used in cooling water, and other
non-hydrocarbon, non-hazardous services, where the design pressure does not exceed
2050 kPag (300 psig).
When approved by the Principal, double-jacketed gaskets may be used for services where
the design pressure does not exceed 2050 kPag (300 psig), the design temperature does
not exceed 260°C (500°F), and the nominal gasket diameter does not exceed 1 m
(40 in). Filler metal shall be graphite, unless otherwise specified. Jacketed gaskets shall
not be used in hydrogen service, very toxic service, wet H2S service, or cyclic service.
Solid metal gaskets shall not be used, except where self-energizing sealing rings with
clamp connectors, welded lip-seal type, or welded diaphragm type gaskets are specified on
the data/requisition sheet.
The minimum width and thickness of the peripheral ring portion of approved gasket types
shall be in accordance with Table 10.
TABLE 10
GASKET TYPES
Type
Gasket Description
1
Spiral-wound with graphite filler
2
Serrated metal gasket with graphite facing
Minimum
width
mm
10.0
Minimum
thickness
mm
4.5
(NOTES 1, 3)
(NOTE 3)
3
Exfoliated graphite sheet gasket with one (1)
stainless steel reinforcement insert,
expanded or tanged.
4
Double-jacketed with graphite filler
12.0
3.0
(NOTE 2)
(NOTE 2)
9.5
1.5
12.0
3.0
(NOTE 3)
NOTES:
1. Spiral-wound gaskets used on flanged external girth joints or floating heads shall be provided with
an inner ring. An outer (centering) ring is not required when the flange is recessed to provide
DEP 31.21.01.30-Gen.
February 2011
Page 36
confinement on the OD of the gasket. Spiral wound gaskets shall not be used when the nominal
diameter is 1500 mm (60 in) or larger.
2. For shell diameters above 1000 mm (40 in) the minimum width and thickness of serrated metal
gaskets shall be 16 mm (5/8 in) and 4 mm (5/32 in).
3. For seawater applications, gaskets containing graphite (with or without reinforcing metal) are
susceptible to galvanic corrosion and shall not be used. Suitable alternatives are bi-axially
expanded PTFE and non-asbestos gaskets made from compressed fibres with rubber binders.
Where two (2) gasketed joints are compressed by the same bolting, the gaskets shall be of
the same type and and the area of gasket facing shall be selected so as to ensure effective
sealing of both gaskets for the applied bolt load. This shall be demonstrated with
calculations, for approval by the Principal.
7.10.2
Add to this clause:
The minimum width of all pass partition groove gaskets shall be 10 mm (3/8 in).
7.10.7
Add to this clause
f) Serrated metal gaskets shall have a flat smooth profile (modified DIN type) and a
width/thickness ratio of 4 or higher. The groove pitch shall be 1.0 mm (0.04 in). The
exfoliated expanded graphite facing shall have a thickness of 0.5 mm (0.02 in) on each
side.
g) Serrated metal gaskets shall be machined in one piece, after completion of all section
welds.
Add new clause:
7.10.10 Unless otherwise specified on the data/requisition sheet, gaskets for permanently blinded
nozzles such as vents and drains, manways, and interconnecting nozzles of stacked
exchangers shall be spiral wound, graphite-filled, with centering and inner rings. The
Contractor shall specify the required gasket materials for the windings, centering and inner
rings in accordance with the respective piping classes for shell and tube side piping on the
data/requisition sheet. When a connection type other than a raised face flange is specified
on the data/requisition sheet for either the shell or tube side inlet and outlet connections,
the type of flange and gasket used for permanently blinded nozzles on the shell or tube
side shall be of the same type and material as the corresponding inlet and outlet
connections.
7.11
HANDLING DEVICES
7.11.1
Add to this clause:
TEMA Type "T" multi-pass floating head covers 760 mm (30 in.) nominal diameter and
larger shall have a centrally located lifting lug.
7.11.3
Add to this clause:
Stationary tubesheets shall have two (2) or more holes UNC threaded for the insertion of
eyebolts for removal of the tube bundles from the shells. The required size and length of
threads for the eyebolt shall be designed for a pulling force based on at least 150% of the
bundle mass. The threads shall be well formed and be a tight fit for maximum grip.
For clad or weld overlayed tubesheets in hydrogen service, over-sized holes shall be filled
with weld overlay, drilled, and then UNC threaded. For clad tubesheets in other services,
inserts of the same material as the cladding, with UNC threaded holes, may be screwed
into the tubesheet and welded to the cladding as shown in Appendix 3, Figure 2. Inserts
shall be 100% liquid penetrant examined after machining. Attention shall be given to the
possibility of pulling out the insert and stripping the cladding when using force to remove
the tube bundle, particularly when the material of the cladding is non-ferrous.
Removable threaded plugs shall be provided to protect the eyebolt holes during operation.
The plugs shall be of a material equivalent to the tubesheet, applied cladding, or weld
overlay.
DEP 31.21.01.30-Gen.
February 2011
Page 37
7.11.4
Replace this clause by:
All vertical exchangers shall be provided with lifting devices for the entire exchanger and a
tailing lug. The lifting device shall be located such that the exchanger weight is not carried
through bolted joints and shall be above the centre of gravity of the exchanger.
Add new clause:
7.11.5
When specified by the Contractor, exchangers with removable bundles that meet both of
the following criteria shall have two (2) clamps welded to the shell flange to facilitate a
bundle puller:
•
Full diameter stationary tubesheet (TEMA Type B); and,
•
Nominal shell diameter greater than 1000 mm (40 in).
The clamps shall be 150 mm (6 in) x 150 mm (6 in) and have a thickness suitable for a
bundle pulling load based on 150% of the bundle mass. The clamps shall be located in
each of the two (2) lower quadrants, with a centre-centre distance of approx. 460 mm
(18 in).
If other provisions are required they shall be stated in the project specification or on the
data/requisition sheets.
Add new clause:
7.11.6
A minimum of three (3) jack bolts shall be provided in girth flanges and tubesheets.
Add new clause:
7.13
CARBON STEEL IN WET HYDROGEN SULFIDE SERVICE
7.13.1
If the shell side fluid is designated as wet H2S service, fixed tubesheet type designs shall
not be used:
7.13.2
Distributor belts or partial distributors shall not be used.
7.13.3
The minimum nozzle size shall be DN 50 (NPS 2). Nozzles DN 150 (NPS 6) and smaller
shall be long weld neck type.
7.13.4
The minimum shell diameter shall be DN 200 (NPS 8). For shells with nominal diameters
between DN 200 (NPS 8) and DN 600 (NPS 24):
•
Shell covers shall be removable;
•
All nozzles shall be located at the ends of the shell cylinder to permit inspection of
the inside surfaces of the nozzle-to-shell welds by the wet-fluorescent magnetic
particle method, after post-weld heat treatment;
•
The shell cylinder shall be a single length of seamless pipe. Rolled plate may only
be used if there is sufficient access to the internal surfaces of the circumferential
and longitudinal welds to be ground flush with the shell, and inspected by the wetfluorescent magnetic particle method after post-weld heat treatment.
Add new clause:
7.14
KETTLE-TYPE REBOILERS AND EVAPORATORS
7.14.1
The tube-to-shell clearance shall be at least 50 mm (2 in.) at any place in the bundle. The
bundle supports shall not obstruct the liquid circulation to the tube bundle and shall have
cut-outs below the bottom row of tubes to facilitate distribution of feed flow along the full
length of the bundle.
7.14.2
The height of weir plates, when provided, shall be at least 50 mm (2 in) above the top tube
row. Unless required by process considerations, there shall be no drain holes in the weir. A
DN 50 (NPS 2) drain nozzle, with blind flange, shall be provided upstream of the weir plate
to facilitate draining.
DEP 31.21.01.30-Gen.
February 2011
Page 38
7.14.3
The diameter of the kettle shall take into account that frothing is likely to occur above the
liquid level. A minimum allowance of 125 mm (5 in) shall be made for this frothing. The
height of the escape area above the frothing allowance shall be at least 250 mm (10 in).
7.14.4
Vapour velocities shall not exceed the maximum value defined by the entrainment (liquid
carryover) requirement specified in the data/requisition sheet by the Contractor.
7.14.5
The total liquid volume shall be determined by the liquid hold-up requirements specified by
the Contractor.
7.14.6
Where the liquid level is controlled by instrumentation, a calming baffle shall be installed to
prevent boiling turbulence from affecting the level instruments.
7.14.7
If removable internals (such as demisters, spider pipe, splash plates, etc.) are specified,
they shall be sized to fit through the manway.
7.14.8
The vapour nozzle(s) shall be positioned to equalize the horizontal vapour velocity above
the liquid level at the nozzle. Calculations and nozzle locations shall take into account any
non-uniform vapour load over the tube length due to either flash vapour at the inlet nozzle
or a non-uniform flux profile. The velocity head in vapour outlet nozzles shall not exceed
3750 kg/m-s2 (2500 lb/ft-sec2).
7.14.9
A vortex breaker, in accordance with Standard Drawing S 10.010, shall be provided for the
liquid outlet nozzle.
7.14.10 A bundle hold-down bar, welded to the shell I.D., shall be provided for all shells with
removable bundles. The bar shall be located at the baffle furthest from the stationary
tubesheet.
7.14.11 The shell side inlet nozzle for kettle reboilers shall normally be located at the bottom of the
shell and adjacent to the front tubesheet, with the following exceptions:
•
For a 2-phase vapour/liquid mixture the inlet nozzle shall be located above the
boiling pool. Spider pipes or a splash plate shall be used to direct the flow
downwards to promote separation.
•
For an inlet temperature which is 28°C (50°F) or more below the boiling point, the
shell side inlet nozzle shall be located on the side of the shell, mid-way along the
tube length at two-thirds of the liquid level. A means for distribution of the highly
sub-cooled feeds axially along the tube bundle shall be provided. An internal pipe
distributor or multiple inlet nozzles may be used for this purpose.
•
For waste heat exchangers in high temperature gas cooling applications specified
as kettle-type, an internal distributor pipe shall not be used. The feedwater inlet
nozzle shall be located directly adjacent to the front tubesheet to ensure that a
dedicated quantity of fresh feedwater is provided to prevent film boiling and dry-out
in the hottest section of the bundle. Additional feedwater inlet nozzle(s) shall be
provided along the length of the tube bundle. The Principal shall approve the
proposed details of the Supplier’s design.
7.14.12 Requirements for spider pipes are as follows:
a)
They shall be located at the position of lowest vapour generation (lowest delta T);
b)
The mixed vapour/liquid stream should be directed downwards against the shell
wall to promote separation of the liquid and vapour;
c)
There shall be no holes in the direct path of the inlet nozzle;
d)
The velocity head in the inlet nozzle shall not exceed 4000 kg/m-s2 (2680 lb/ft-sec2);
e)
The velocity head in the spider header shall not exceed 1000 kg/m-s2 (670 lb/ftsec2);
f)
The velocity head in the holes shall not exceed 4000 kg/m-s2 (2680 lb/ft-sec2);
g)
Provisions shall be made for cleaning of the spider pipe.
DEP 31.21.01.30-Gen.
February 2011
Page 39
7.14.13 Requirements for splash plates are as follows:
•
The velocity head in the inlet nozzle shall not exceed 4000 kg/m-s2 (2680 lb/ft-s2);
•
The velocity head in the splash plate header shall not exceed 1000 kg/m-s2 (2680
lb/ft-s2).
7.14.14 When the boiling range is greater than 55°C (100°F), or the boiling fluid contains a nonvolatile component:
•
An intermittent blow down connection shall be provided at the weir end of the
bundle;
•
The minimum clearance between the bottom of the tube bundle and kettle inside
diameter shall be a minimum of 150 mm (6 in);
•
Vertical cut half supports, rather than full supports, shall be provided. A cut-out
shall be provided in the baffles under the bottom row of tubes.
7.14.15 For amine or sulfinol reboiler service:
•
The bundle shall be rotatable about the horizontal axis;
•
The shell entrance area shall be greater than or equal to the nozzle area (based on
inside diameter);
•
The minimum liquid level above the top tube row shall be 150 mm (6 in).
Add new clause:
7.15
EMBAFFLETM HEAT EXCHANGERS
7.15.1
EMbaffle designs shall use dummy tubes and/or blinding plates to block longitudinal
leakage flow areas when the height under a nozzle exceeds 25 mm (1 in).
7.15.2
Annular distributors (vapor belts) may be considered to limit the un-tubed height under
nozzles. The use of annular distributors requires approval of the Principal.
7.15.3
A combination of EMbaffle and conventional segmental baffles may be used for mechanical
purposes to reduce the potential for tube vibration that may exist with conventional
segmental baffles only.
7.15.4
EMbaffle intermediate supports for NTIW baffles may be applied for mechanical benefit to
reduce the unsupported tube span.
7.15.5
Thermal enhancements from the use of EMBaffles as specified in clauses 7.15.3 and
7.15.4 shall be neglected, however the effects on the pressure drop shall be assessed.
Add new clause:
7.16
TRANSITIONS
The half-apex angle of conical transition sections (measured from the center-line of the
exchanger) shall not exceed 30 degrees.
DEP 31.21.01.30-Gen.
February 2011
Page 40
8.
MATERIALS
8.1
GENERAL
8.1.1
Replace this clause by:
Materials, fabrication, and testing of heat exchangers in H2S containing environments (sour
service) in Upstream applications or wet hydrogen sulphide service in Downstream
applications shall be in accordance with DEP 30.10.02.15-Gen. or DEP 30.10.02.17-Gen.,
as applicable, when specified by the Contractor on the equipment data/requisition sheet.
When wet hydrogen sulphide servide is applicable, the severity rating shall be included on
the data/requisition sheet.
8.1.2
Replace this clause by:
Gray cast iron, ductile cast iron, and malleable iron shall not be used.
Add new clause:
8.1.6
If the tubesheet forms a flange or is directly welded to the shell it shall be supplied as a
forging and not as plate material.
Add new clause:
8.1.7
Galvanized materials or zinc containing paints shall not be used in direct contact with
exposed stainless steel or high nickel alloy pressure components.
Add new clause:
8.1.8
Where alloy clad or weld overlayed pressure components are specified on the
data/requisition sheet, substitution with solid alloy components is not permitted, unless
approved by the Principal.
Add new clause:
8.1.9
Dis-similar metal welds shall not be used for pressure boundary welds, unless approved by
the Principal. Dis-similar metal welds SHALL [PS] not be used for pressure boundary
welds of heat exchangers which are in hydrogen service (e.g. Texas Towers in CCR
Platformer Units).
8.1.10
Materials used for the fabrication of pressure retaining components shall be traceable to
suppliers which have a quality management system which is approved by the International
Standards Organization, ISO 9001.
8.2
GASKETS
8.2.3
Replace this clause by:
Unless otherwise specified, material for spiral wound, serrated metal, gaskets shall be 304
or 316 grade stainless steel. Low carbon grades of 304 or 316 stainless steel shall be used
when gaskets are made with welds. Where the gasket contact surface of the flange or
tubesheet is of a higher alloy, the gasket material shall match the chemical composition of
that alloy, unless otherwise specified on the data/requisition sheet.
Add new clause:
8.2.6
For gaskets on the cooling water side of exchangers with stainless steel flanges or
tubesheets, graphite and ‘full density’ PTFE shall not be used. Expanded PTFE (e.g. GoreTex type), can be used. Only PTFE that contains no free fluoride ions (F-) is allowed in
contact with the stainless steel.
8.3
TUBES
Add new clause:
8.3.4
When copper nickel tubes are specified for corrosive water service by the Contractor, an
electrochemical test shall be completed. The electrochemical test procedure and
requirements are given in Appendix 2.
DEP 31.21.01.30-Gen.
February 2011
Page 41
Add new clause:
8.3.5
When aluminium brass tubes (as defined in ASTM B 111) are specified for corrosive water
service on the data/requisition sheet, the following additional requirements shall apply:
a)
Tubes shall be supplied in the fully annealed condition;
b)
Tubes shall be supplied in clean condition (free form grease, machining oils, etc.) to
allow surface passivation by others;
c)
Where the aluminium brass tubes are integrally finned, they shall only be used in
the fully annealed condition (i.e. the tubes shall receive a final full-anneal heat
treatment after the last finning operations);
d)
Aluminium brass tubes (bare or low-finned) shall meet the requirements of the
stress corrosion susceptibility tests as specified in ASTM B 154, ASTM B 858,
ISO 196 or ISO 6957, after completion of the final heat treatment and straightening
of tubes;
e)
Sacrificial anodes shall be used.
Add new clause:
8.3.6
When specified by the Contractor, the Supplier shall provide one piece of sample tubing for
each equipment number with the same diameter, thickness, material, and the same heat as
the tubes used in fabrication. The minimum length of the sample for straight tubes shall be
1.5 m (5 ft). A stainless steel wire tag shall be attached to the sample tube referencing the
equipment tag number.
Add new clause:
8.4
EXTERNAL BOLTING
8.4.1
External bolts and nuts shall conform to Table 11, regardless of whether the flange,
tubesheet, and channel cover materials are carbon steel, low alloy steel, austenitic or nonferrous materials:
TABLE 11 BOLTING AND NUT MATERIALS
Temperature
Bolt Material
Nut Material
-150 to -21
A-320 Gr.L7
A-194 Gr.4
-101 to -30
-150 to -21
A-320 Gr.L7M (NOTE 1)
A-194 Gr.7M (NOTE 1)
-40 to 427
-40 to 800
A-193 Gr.B7
A-194 Gr.2H
-29 to 427
-20 to 800
A-193 Gr.B7M (NOTE 1)
A-194 Gr. 2HM (NOTE 1)
428 to 538
801 to 1000
A-193 Gr.B16
A-194 Gr.4
°C
°F
-101 to -41
NOTES:
1. Sour or wet H2S service.
2. For temperatures outside these ranges, the Principal shall be consulted for guidance.
Internal bolting material of exchangers with high alloy tube bundles shall be equivalent to
the tubesheet material with respect to corrosion properties, unless otherwise specified.
Add new clause:
8.4.2
Cadmium plated bolts shall not be used.
Add new clause:
8.4.3
Nuts shall have a height at least equal to the bolt diameter.
DEP 31.21.01.30-Gen.
February 2011
Page 42
Add new clause:
8.5
CATHODIC PROTECTION
8.5.1
When cathodic protection is required for heat exchangers in corrosive water systems, the
Contractor shall indicate the type of protection (sacrificial anodes, impressed current
systems or internal coatings) and supply relevant details as per DEP 30.10.73.10-Gen.
8.5.2
Studs required for sacrificial anodes shall have the same type of screw thread as used for
other bolting of the heat exchanger.
8.5.3
Sacrificial anodes or plates shall not obstruct the tube side flow.
8.5.4
For correct mounting of anodes refer to drawing S 21.072.
DEP 31.21.01.30-Gen.
February 2011
Page 43
9.
FABRICATION
9.1
SHELLS
Add new clause:
9.1.4
Shells shall be fabricated from rolled plate for the smallest diameter that is practicable. Line
pipe up to a nominal diameter of DN 600 mm (24 in) may be used for carbon steel shells.
9.2
PASS-PARTITION PLATES
Add to this clause:
Longitudinal baffles which are welded to the shell shall also meet these requirements.
Add new clause:
9.2.1
Drain holes shall be provided in pass partition plates to facilitate drainage. Drain holes shall
have a maximum diameter of 6 mm (1/4 in).The location, size, and number of drain holes
shall be indicated on the fabrication drawings and subject to the approval of the Contractor.
Add new clause:
9.2.2
To allow full compression of the peripheral ring portion of gaskets, the free edge of pass
partition plates shall be machined to provide a true plane with the peripheral gasket seating
surface of the flange, so that pass partition plates do not interfere with sealing of the
peripheral portion of the gasket.
9.5
WELDING
9.5.1
Replace this clause by:
All welding, welding procedures and qualification testing, and welder performance testing
shall be as per DEP 30.10.60.18-Gen or applicable project welding specification. Welding
procedures and qualifications shall be approved by the Contractor prior to the start of
fabrication.
9.5.6
Replace this clause by:
If a welded tube-to-tubesheet joint is specified on the equipment data sheet, it shall be a
“full” strength-welded joint in accordance with ASME Section VIII, Division 1. Autogeneous
seal welds are not permitted.
The qualification of the strength-welded tube-to-tubesheet joints shall be in accordance with
the requirements of ASME Section IX, paragraph QW-193 or applicable pressure deisgn
code. The following additional requirements shall apply if a strength-welded tube-totubesheet joint is specified:
a)
A minimum of two (2) weld passes shall be applied using the GTAW technique.
b)
The length of the combined weld legs measured parallel to the longitudinal axis of
the tube at its outside diameter shall be at least 1.4 times the nominal thickness of
the tube.
c)
A tensile pull-test shall be performed on the qualification test coupon. A minimum
of three (3) tests shall be performed.
d)
A micro-hardness survey for weld metal, heat affected zones, and base metals
shall be provided on the qualification test coupon for the following cases:
i. Carbon and low alloy steels in wet hydrogen sulphide or sour service.
Micro-hardness values shall not exceed 248 HV10.
ii. Materials subject to hardening during welding and cooling (e.g.
ferritic/martensitic stainless steels, and duplex stainless steels). Microhardness acceptance criteria shall be specified by the Principal.
DEP 31.21.01.30-Gen.
February 2011
Page 44
The degree of expansion shall be agreed between the Supplier and the Contractor, with
consideration of the tube and tubesheet materials, hardness, and potential for work
hardening during the expansion process.
Add new clause:
9.5.11
If external or internal attachments such as clips, lugs, or vortex breakers intersect a
pressure weld, the attachment shall be trimmed to a radius of 25 mm (1 in) to straddle the
weld.
9.6
HEAT TREATMENT
9.6.2
Replace this clause by:
Unless otherwise specified, the following tube materials shall be subject to heat treatment
after bending:
•
Heat treatment of the bend area for carbon steel and low alloy steel U-tubes
having a mean radius smaller than 5 times the nominal tube OD;
•
Heat treatment of the bend area for all carbon steel and low alloy steel U-bends
when wet H2S service is specified;
•
Solution annealing for 304 and 316 grade stainless steel U-bends having a mean
radius smaller than 5 times the nominal tube OD. 304 and 316 grade stainless steel
tubes shall be supplied as low carbon grade (or dual certified as low carbon grade)
when solution annealing of the U-bends will be conducted;
•
Bends in aluminium and copper alloys.
At least 150 mm (6 in) of the adjacent straight length shall be heat-treated for the materials
referenced above.
For 12 and 17 Cr, duplex stainless steel, and nickel alloys, heat treatment of U-tubes shall
only be applied when approved by the Principal.
In all cases, the method and extent of the heat treatment of U-tubes shall be agreed to
between the Supplier and the Principal. Special consideration shall be given to the
transition zone during heat treatment as it could induce embrittlement or susceptibility to
stress corrosion in the transition zones between the straight legs of the U-tube and the Ubend.
Open flame heat treatment is not acceptable.
9.6.4
a) Add to this clause:
Post-weld heat treatment shall be applied to carbon and low alloy steel bonnets and
floating head covers if there are 4 or more tube side passes and the partition plates are
in two (2) different planes.
Add new clause:
9.6.8
If post-weld heat treatment is required, it shall conform to DEP 31.22.20.31-Gen and
DEP 30.10.60.18-Gen.
Add new clause:
9.6.9
Heat treatment charts are required for all heat treatment operations including hot forming of
ferrous material above the lower critical transformation (ACI) temperature.
9.7
DIMENSIONAL TOLERANCES
Add new clause:
9.7.4
The tolerance of the centre-to-centre distance between the parallel legs of the U-tubes shall
be in accordance with ASTM A 556, regardless of the tube material.
DEP 31.21.01.30-Gen.
February 2011
Page 45
9.8
GASKET CONTACT SURFACES OTHER THAN NOZZLE-FLANGE FACINGS
9.8.2.
Replace this clause by:
The flatness tolerance on peripheral gasket contact services shall be in accordance with
Table 3 of ISO 16812, regardless of service.
9.8.4
Replace this clause by:
The flatness tolerance on pass-partition grooves and mating pass-partition plate edges
shall be +0 / - 0.20 mm (- 0.008 in).
9.9
TUBE HOLES
9.9.1
Add to this clause:
The edge of the first groove shall be located at least 6 mm (1/4 in), plus the specified
corrosion allowance, from the face of the tubesheet. The distance between grooves (edgeto-edge) shall be at least 6 mm (1/4 in). If the tubesheet thickness prevents the this form
being achieved, and the distance between grooves (edge-to-edge) is less than or equal to
5 mm (3/16 in), the tube joint strength shall be qualified by pull-out testing in accordance
with ASME Section VIII, Division 1, non-mandatory appendix A.
9.10
TUBE-TO-TUBESHEET JOINTS
9.10.1
Add to this clause:
A minimum of 2% of the tubes per tube bundle, with a minimum of five (5) tubes, shall be
randomly checked for conformance to this requirement.
Add new clause:
9.10.5
Tubes shall be expanded to within 3 mm (1/8 in) of the shell side face tubesheet, to
minimize the crevice between the tubes and tubesheet holes. For welded tube-to-tubesheet
joints without expansion grooves, tube expansion shall be completed after welding, and
shall consist of a contact roll with 1% to 3% tube wall thickness reduction. When tube end
welds are subjected to post weld heat treatment, the final tube expansion shall be
completed after post weld heat treatment.
Add new clause:
9.10.6
The ends of tubes shall extend by at least 1.5 mm (1/16 in), but not by more than 5 mm
(3/16 in) beyond the tubesheet face
9.11
ASSEMBLY
9.11.2
Add to this clause:
The proposed thread lubricant shall be nickel-based and shall be suitable for the exchanger
operating temperature. All thread lubricants shall be free of zinc and cadmium. Lubricants
used on stainless steel materials shall be certified to be free of chlorides. Copper or
molybdenum disulphide containing thread lubricants shall not be used. The Supplier shall
provide details of the proposed lubricant for review.
Add new clause:
9.11.3
When installing gaskets, a light coat of spray adhesive may be applied on the gasket
seating surface to hold the gaskets in place during assembly. The adhesive shall be
capable of carburizing into a stable substance above 100°C (210°F) without compromising
the integrity of the gasket or seal. The use of tape, shellac, glue, compounds, lead, or
grease on gaskets is not permitted.
Add new clause:
9.11.4
External girth flange and floating head flange bolting shall be tightened with a calibrated
manual torque wrench, hydraulic torque wrench, pneumatic torque wrench, or bolt
tensioning devices. Bolt tensioning shall be applied when specified in [7.8.7]. The Supplier
shall perform calibration/bench testing on a annual basis and shall retain testing records.
DEP 31.21.01.30-Gen.
February 2011
Page 46
Hammering or use of impact wrenches shall not be used to tighten bolts. When torquing is
applied, the calculation of the torque value shall be in accordance with ASME PCC-1-2010
Appendix K.
Add new clause:
9.11.5
Floating head flanges shall be re-tightened after the tubeside hydrotest is completed and
prior to installation of the bundle inside the shell or prior to installing the shell cover.
Add new clause:
9.11.6
Horizontal removable bundles shall have the stationary tubesheet stamped "TOP" to indicate
proper orientation in the shell. Vertical removable bundles shall have match marks on the
stationary tubesheet and adjoining shell girth flange at the zero degree position indicated on
the general arrangement drawing.
Add new cause:
9.12
INSULATION SUPPORTS
9.12.1
When insulation is specified on the data/requisition sheet, insulation supports and nozzle
drip rings shall be provided per Standard Drawings S20.003 (Sheets 1 to 4).
9.12.2
Support clip pads shall be radiused and provided with a 6 mm (1/4 in) vent hole.
9.12.3
When skirts are provided on vertical exchangers, heat shields and insulation supports shall
be provided on the skirt per Standard Drawing S20.001 and S20.002 (Sheet 1).
DEP 31.21.01.30-Gen.
February 2011
Page 47
10.
INSPECTION AND TESTING
10.1
QUALITY ASSURANCE
10.1.2
Replace this clause by:
Defective tubes shall be replaced with new tubes, where bundle type and access permits.
Where tubes are not practically accessible for replacement, as defined in TEMA
RGP-RCB-2, the method of plugging shall be approved by the Principal. Where plugs are
welded, the welding procedure shall be approved by the Principal.
10.2
QUALITY CONTROL
10.2.5
a) Replace this clause by:
Hardness testing of weld procedure qualifications and pressure retaining production
welds shall be in accordance with DEP 30.10.60.18-Gen and the applicable pressure
design code.
c) Replace this clause by:
Hardness limits shall be in accordance with DEP 30.10.60.18-Gen. or the applicable
pressure design code, whichever is more stringent.
Add new clause:
g) When sour or wet hydrogen sulphide service is specified, the weld procedure
qualification and production hardness testing shall also comply with DEP 30.10.02.15Gen. or DEP 30.10.02.17-Gen., as applicable.
Add new clause:
10.2.12 For stainless steels, ferritic alloy steels with a chromium content greater than 0.5%,
non-magnetic materials, or clad plate construction in any material, the root pass and final
passes of welds not subject to full radiography shall be examined by the magnetic-particle
or liquid-penetrant method.
Add new clause:
10.2.13 After expanding of tubes, 100% of tube end welds shall be examined by the liquidpenetrant method. Any repairs to tube end welds shall be re-examined by the same
method.
Add new clause:
10.2.14 Where welded carbon, ferritic alloy, and austenitic alloy steel tubes are supplied, they shall
be subjected to a non-destructive electro-magnetic test in accordance with ASTM A 450.
For seamless tubes, a non-destructive electro-magnetic test shall be used in lieu of a
hydrostatic test. Electric test shall cover the entire metal volume of the tube. Mill test reports
shall verify the type and extent of the all non-destructive tests applied to the tubes.
10.2.15 Circumferential low-finned tubes shall be eddy-current tested by the tube mill, after the fin
extrusion process. Surface cracking at the fin or wall shall not be accepted.
Add new clause:
10.2.16 All tubes, seamless or welded, for exchangers whose design pressure exceeds 13.8 MPag
(2000 psig) SHALL [PS] be hydrostatically tested in accordance with ASTM A 450 or other
appropriate ASTM specification, in addition to any non-destructive electric testing as
required.
Add new clause:
10.2.17 All non-destructive testing including radiography, ultrasonic, liquid penetrant, magnetic
particle, hardness, chemical analysis, and impact testing shall also meet the requirements
in DEP 31.22.20.31-Gen or other applicable pressure vessel DEP. All non-destructive
examination and testing procedures, and specific NDE and test plans for each equipment
item, shall be submitted to the Contractor for review and acceptance.
DEP 31.21.01.30-Gen.
February 2011
Page 48
10.3
PRESSURE TESTING
10.3.3
Add to this clause:
When specified, hydrotest water shall be tested to ensure that there is no potential for
Microbiological Induced Corrosion (MIC). The Principal shall be consulted for testing
requirements.
10.3.4
Replace this clause by:
Water used for hydrostatic testing of exchangers made from martensitic and ferritic grades,
12 and 17 Cr stainless steels (ANSI Types 405, 410, and 430), 18-8 stainless steels (300
series austenitic), duplex grades (Alloy 2205, Alloy 2507, and Alloy 20), and Alloy 400
(Monel), shall not contain traces of any type of sediment or more than 20 ppm chloride by
mass. The bundle and exchanger shall be drained and dried in accordance with clause
10.3.5 following hydrostatic testing with water.
10.3.5
Replace this clause by:
Exchangers made from martensitic and ferritic grades, 12 and 17 Cr stainless steels (ANSI
Types 405, 410, and 430), 18-8 stainless steels (300 series austenitic), duplex grades
(Alloy 2205, Alloy 2507, and Alloy 20), and Alloy 400 (Monel), low-fin tube bundles of
carbon and low alloy steel materials, and all other exchangers specified with special
preparation for shipment per clauses 11.1.10 and 11.1.11, shall be thoroughly dried after
hydrostatic testing with water by blowing with warm air or nitrogen. Maximum temperature
of air/nitrogen shall be 60°C (140°F). Drying procedures shall be submitted to the
Contractor for review and approval.
For exchangers operating at sub-zero temperatures, the Principal shall be consulted for
drying requirements.
10.3.11 Add to this clause:
Gaskets used between the intermediate nozzles of stacked exchangers during the
hydrotest shall be of the same type used in service. The gaskets used for the hydrotest
shall be removed and discarded, if the exchangers are not shipped in the stacked position.
Add new clause:
10.3.12 Bellows type expansion joints shall be hydrotested in the bellows manufacturer’s shop.
Add new clause:
10.3.13 No preliminary hydrostatic tests shall be made on any exchanger. Exchangers or their
component parts shall not be subjected to a proof hydrostatic test.
Add new clause:
10.3.14 The following sequences of pressure testing shall be carried out for different types of heat
exchangers:
a) For fixed tubesheet exchangers the shellside shall be tested first, with both bonnets or
channel covers removed. The bonnets or channel covers shall then be installed and the
tubeside tested;
b) For U-tube exchangers, if the tubeside test pressure is higher than the shellside test
pressure, then the tubeside shall be tested first with the bundle removed from the shell.
The bundle must be properly supported to prevent distortion during testing. The bundle
shall then be installed in the shell and the shellside tested with the bonnet or channel
cover removed. If the shellside test pressure is the higher, then the shellside shall be
tested first with the bonnet or channel cover removed. The bonnet, or channel cover,
shall then be installed and the tubeside tested with the bundle installed in the shell;
c) For floating head heat exchangers, if the tubeside test pressure is higher than the
shellside, then the tubeside shall be tested first with the bundle removed from the shell.
The bundle must be properly supported to prevent distortion during testing. The bundle
shall then be installed in the shell, and the shellside tested with the channel or channel
cover removed, and the floating head and the shell cover removed. The Supplier shall
DEP 31.21.01.30-Gen.
February 2011
Page 49
provide a test ring and gland assembly for sealing at the floating tubesheet. The floating
head and shell cover shall then be installed and the shellside retested;
d) If the shellside test pressure is higher than the tubeside, then the shellside shall be
tested first with the bonnet or channel cover removed, the floating head and the shell
cover removed and the test ring and gland assembly fitted at the floating tubesheet. The
channel or channel cover and the floating head shall then be fitted and the tubeside
tested with the bundle fitted to the shell. The shell cover shall then be installed and the
shellside retested;
e) When the construction does not permit access to both tubesheets for leakage during the
shell side hydrostatic test (TEMA T type with an integral shell cover), a 350 kPag
(50 psig) air test shall be applied to the tube side with the shell full of water. Any bubbles
observed shall be cause for rejection.
Gaskets used during the hydrotest shall be the same type used in service.
10.4
NAMEPLATES AND STAMPINGS
10.4.1
Add to this clause:
The nameplate shall be in accordance with Standard Drawing S 10.114. Modified
nameplate details may be required to comply with local requirements. A warning nameplate
shall also be provided to identify any restrictions such as differential pressure design and
testing, or any limitations on the operation and testing of expansion joints (external or
internal type), when applicable.
10.4.3
Add to this clause:
All parts identified shall be stamped with the Purchaser’s exchanger number (the
manufacturer's serial number may also be added).
10.4.4
Add to this clause:
•
Purchase requisition number;
•
Purchaser’s service name and equipment number.
Add new clause:
10.5
TEST RING AND TEST FLANGE
Heat exchangers with split ring floating heads (S type) shall be provided with a test ring with
packing gland. Each unit of identical heat exchangers performing a common duty shall be
equipped as follows:
•
One (1) test ring, for two (2) bundles per unit;
•
Two (2) test rings, for three (3) or more bundles per unit;
•
Two (2) test rings, for stacked exchangers with direct inter-connections.
Add new clause:
10.6
REPAIRS
10.6.1
Unless otherwise approved by Principal, all welding repairs made after any non-destructive
testing, post-weld heat treatment, or pressure testing shall require the equipment to be reheat treated, re-inspected and re-pressure tested accordingly to cover the scope of the
repairs.
10.6.2
Repair plans shall be submitted for review and approval by the Principal, prior to the start of
any repairs.
DEP 31.21.01.30-Gen.
February 2011
Page 50
11.
PREPARATION FOR SHIPMENT
11.1
PROTECTION
11.1.3
Replace this clause by:
Flange faces not supplied with a permanent blind flange shall be protected with 3 mm
(1/8 in) thick steel covers with 1.5 mm (1/16 in) thick composition or neoprene gaskets
secured to the flange with a minimum of four (4) bolts. If permanent blind flanges are
provided, the blind flanges and gaskets shall be of the appropriate pressure class.
11.1.4
Replace this clause by:
Flange faces and other machined surfaces, including bolts and threaded couplings, of
ferritic materials shall be coated with a rust preventative such as Shell Ensis Compound
DW 1016, Valvoline Tectyl 891 Class 1, E.F. Houghton and Company Rust Veto 344, or a
Principal-approved substitute.
11.1.5
Delete this clause.
11.1.7
Replace this clause by:
Surface preparation and paint, when required, shall be in accordance with the applicable
project painting specification (DEP 30.48.00.31-Gen. or equivalent). The Contractor shall
specify the applicable paint code on the data/requisition sheet.
Add new clause:
11.1.10 Special preparation for shipment shall be applied to both shellside and tubeside for
exchangers with components made from martensitic and ferritic grades, 12 and 17 Cr
stainless steels (ANSI Types 405, 410, and 430), 18-8 stainless steels (300 series
austenitic), duplex grades (Alloy 2205, Alloy 2507, and Alloy 20), and Alloy 400 (Monel).
Special preparation shall consist of the following:
a)
Exchangers shall be prepared for shipping immediately after they are hydro-tested
and dried or pneumatically tested.
b)
Openings shall be sealed with gasketed and fully bolted blind flanges.
c)
A connection with a valve and a pressure gauge shall be installed.
d)
Exchangers that were hydro-tested shall be pressurized and depressurized twice to
100 kPag (15 psig) with dry nitrogen or argon, and then re-pressurized to 100 kPag
(15 psig) with -29°C (-20°F) dew point nitrogen or argon. Exchangers that were
pneumatically tested shall be pressurized to 100 kPag (15 psig).
e)
Exchanger shells shall be tagged with brightly coloured waterproof labels that state:
“Contents Under Nitrogen (Argon) Pressure; Do Not Open Without Principal’s
Approval”.
Special preparation shall also be applied to equipment that will be transported over-seas,
regardless of the material.
Add new clause:
11.1.11 For over-land transport, and/or extended storage, the Contractor shall indicate on the
data/requisition sheet if special preparation for shipment and/or storage is required.
Add new clause:
11.1.12 Where the shipping weight, and height limitations of the proposed transport route permit,
stacked exchangers shall be shipped with the exchangers in the stacked position.
11.2
IDENTIFICATION
11.2.3
Replace this clause by:
DEP 31.21.01.30-Gen.
February 2011
Page 51
Where applicable, the following markings shall be applied to heat exchangers, located 180°
apart, in letters that are 75 mm (3 in) high:
•
Stationary heads, rear heads, and shells that have been post-weld heat treated
shall have the words:
“Post Weld Heat Treated – Do Not Burn or Weld”;
•
Heat exchangers that have titanium components shall have the words:
"Titanium Equipment - Do Not Perform Hot work".
DEP 31.21.01.30-Gen.
February 2011
Page 52
12.
SUPPLEMENTAL REQUIREMENTS
12.1
GENERAL
Add to this clause:
The supplemental requirements of section 12 SHALL [PS] apply, if any of the following
conditions exist:
a)
Cylinder thickness is ≥ 50 mm (2 in);
b)
Design pressure is ≥ 10.3 MPag (1500 psig);
c)
Carbon steel in high severity sulphide stress cracking (SSC) service, if not provided
with cladding;
d)
Very toxic service;
e)
Pressure or temperature induced cyclic service;
f)
Heat exchangers which operate in the creep range of the materials of construction.
Where the pressure design code is specified as ASME and DEP 31.22.20.31-Gen is
applicable, heat exchangers SHALL [PS] be treated as “Engineered” Pressure Vessels,
except that ASME Section VIII, Division 1 shall be applied, unless specified otherwise by
the Principal.
12.2
DESIGN
12.2.2
Add to this clause:
The welded connections between a tubesheet and the adjacent cylinder SHALL [PS] be in
accordance with ASME Code Figure UW-13.3, Type (a), (b), (c) or equivalent
configurations.
Add new clause:
12.2.3
For equipment in cyclic service:
•
Self-reinforced nozzles in accordance with ASME UW-16.1 Figures (f1), (f2), (f3),
(f4), or (g) or equivalent configurations shall be used;
•
the inside corner of the nozzle-to-head/shell junctions shall be rounded to 25% of
the thickness of the penetrated shell/head but not less than 6 mm (¼ in) or more
than 19 mm (¾ in). All contouring of inside corners in finished openings and in
nozzle necks shall be done before overlay welding, where required. Edges of the
applied weld overlay shall also be rounded.
Add new clause:
12.2.4 Welded tube-to-tube-sheet joints SHALL [PS] be either strength-welded or strength-welded
and expanded, as specified by the Contractor on the equipment data sheet, if any of the
following conditions exist:
•
Design pressure, on either side, is ≥ 10.3 MPag (1500 psig);
•
Pressure or temperature induced cyclic service;
Add new clause:
12.2.5
Hydraulic bolt tensioning shall be applied to flange bolting, if any of the following conditions
(or those in Table 5) exist:
•
Design pressure is ≥ 10.3 MPag (1500 psig);
•
Very toxic service;
•
Pressure or temperature induced cyclic service.
The bolt stress shall be verified via UT extensiometer testing after the final hydrotest.
DEP 31.21.01.30-Gen.
February 2011
Page 53
ANNEX A
RECOMMENDED PRACTICES
Delete:
This Annex is not applicable to this DEP.
ANNEX B
SHELL AND TUBE HEAT EXCHANGER CHECKLIST
Replace this Annex with:
Standard Form DEP 31.21.01.83-Gen. shall be used for additional specific requirements
mentioned on the shell and tube heat exchanger checklist and not already covered by this
DEP or the data/requisition sheets.
ANNEX C
SHELL AND TUBE HEAT EXCHANGER DATA SHEETS
Replace this Annex with:
In conjunction with this DEP, the use of standard forms, requisition and data/requisition
sheets are intended to provide all the data necessary for the description and the design of
shell and tube heat exchangers for petroleum, petrochemical, and natural gas services.
Shell and tube heat exchanger specification sheets shall be replaced by applicable
data/requisition sheets, form DEP 31.21.00.93-Gen., or equivalent.
DEP 31.21.01.30-Gen.
February 2011
Page 54
PART IV REFERENCES
In this DEP, reference is made to the following publications:
NOTES:
1. Unless specifically designated by date, the latest edition of each publication shall be used,
together with any amendments/supplements/revisions thereto.
2. The DEPs and most referenced external standards are available to Shell staff on the SWW (Shell
Wide Web) at http://sww.shell.com/standards/.
SHELL STANDARDS
Materials for use in H2S-containing environments in oil and gas
production (amendments and supplements to ISO 15156:2009)
DEP 30.10.02.15-Gen.
Wet H2S requirements for downstream pressure vessels and
piping
DEP 30.10.02.17-Gen.
Welding of metals (amendments / supplements to API RP 582)
DEP 30.10.60.18-Gen.
Cathodic protection
DEP 30.10.73.10-Gen.
Protective coatings for onshore facilities
DEP 30.48.00.31-Gen.
Pressure vessels (based on ASME section VIII)
DEP 31.22.20.31-Gen.
Gaskets, metal-grooved with a facing layer on both sides,
design to BS EN 1514-4 and prEN12560-6.
MESC SPE 85/100
Graphite gaskets, flat sheets and rings with or without stainless
steel insert(s), design to EN 1514-1 and EN 12560-1.
MESC SPE 85/101
Gaskets, spiral wound, design to EN 1514-2, EN 12560-2 and
ASME B 16.20
MESC SPE 85/103
DATA/REQUISITION SHEETS
Shell and tube heat exchangers
DEP 31.21.00.93-Gen.
Expansion joints
DEP 31.27.30.93-Gen.
STANDARD FORMS
Shell and tube heat exchanger – checklist
DEP 31.21.01.83-Gen.
STANDARD DRAWINGS
Vortex breakers
S 10.010
Bolt length and make-up requirements for tensioning tools
S 10.071
Nameplate with bracket for vessel and heat exchange equipment
S 10.114
Support ring for insulation
S 20.003
Brackets for standard vertical reboilers. Nom. dia. 350 up/incl.
1100 mm
S 21.017
Sacrificial anodes for tubulars
S 21.072
Steel sacrificial plates for tubulars 350 mm nom. dia. and larger
S 21.073
Sliding plate for saddles of horizontal vessels.
S 22.003
Earthing boss for steel structures, tanks, vessels, etc.
S 68.004
DEP 31.21.01.30-Gen.
February 2011
Page 55
AMERICAN STANDARDS
ASME Boiler and Pressure Vessel Code: Rules for construction
of pressure vessels
ASME VIII
Issued by:
American Society of Mechanical Engineers
345 East 47th Street
New York NY 10017
USA
Pipe flanges and flanged fittings NPS 1/2 through NPS 24
metric/inch standard
ASME B16.5
Large diameter steel flanges
ASME B16.47
Guidelines for Pressure Boundary Bolted Flange Joint Assembly
ASME PCC-1-2010
Issued by:
American Society of Mechanical Engineers
ASME International
Three Park Avenue, M/S 10E
New York, NY 10016
USA.
Standard specification for carbon steel bolts and studs, 60 000
psi tensile strength
ASTM A 307
Standard specification for general requirements for carbon
and low alloy steel tubes
ASTM A 450
Standard specification for seamless cold-drawn carbon steel
feedwater heater tubes
ASTM A 556
Specification for straight-beam ultrasonic examination of plain
and clad steel plates for special applications
ASTM A 578
Standard specification for through – thickness tension testing
of steel plates for special applications
ASTM A 770
Issued by:
American Society for Testing and Materials
100 Barr Harbour Drive
West Conshohocken
PA 19428-2959
USA
Standards of the Expansion Joint Manufacturers Association
EJMA standards
Issued by:
Expansion Joint Manufacturers Association, Inc.
707 West Chester Avenue
White Plains, New York 10604, USA.
Standards of the Tubular Exchanger Manufacturers Association
TEMA Standards
9th edition
Issued by:
Tubular Exchanger Manufacturers Association
26 N Broadway
Tarrytown
New York, 10007
USA
Heat transfer calculations for tubular equipment - computer
programmes:
1. HTRI Xchanger Suite
2. Flow-Induced Vibration Analysis Program
Issued by:
Heat Transfer Research Inc.
150 Venture Drive
College Station, Texas 77845,
Xist
Xvib
DEP 31.21.01.30-Gen.
February 2011
Page 56
USA
INTERNATIONAL STANDARDS
Petroleum, petrochemical and natural gas industries - Shell-andtube heat exchangers
Issued by:
International Organisation for Standardisation
Case Postale 56
Geneva 20 Switzerland CH-1211
Copies can also be obtained from national standards organisation
ISO 16812:2007
DEP 31.21.01.30-Gen.
February 2011
Page 57
APPENDIX 1
MATERIALS FOR USE IN SHELL AND TUBE HEAT EXCHANGERS
Table 1-1 provides a basic materials selection for a number of generalised service
conditions. The construction materials specified in this Table are limited to the tube side
(tube bundle, channel floating head, etc.). Materials are referenced by ASTM standards,
however, equivalent ISO or CEN standards, or other equivalent standards, may also be
used with the approval of the Principal. The materials for the shell are not sufficiently
distinctive from other pressure vessels, therefore shell materials selection shall be in
compliance with DEP 31.22.20.31-Gen. or other applicable pressure vessel DEP.
Seven (7) main groups of materials have been considered:
A.
Carbon steel
B.
Low temperature carbon steel
C.
Stainless steels
D.
Copper-based alloys
E.
Duplex stainless steels
F.
Alloy 400 (Monel)
G.
Titanium
The most common types of heat exchangers are considered in Table 1-2, including fixed
tube sheet, floating head and U-tube bundle designs.
The Contractor shall specify on the data/requisition sheet the materials group that will
apply, or the specific materials required for each component.
DEP 31.21.01.30-Gen.
February 2011
Page 58
TABLE 1-1
Item
no.
MATERIALS FOR USE IN SHELL AND TUBE HEAT EXCHANGERS
Component
A
Carbon steel
[1]
B
Low temperature
carbon steel
C
Stainless steel
2a
Channel – shell
(plate, pipe)
A 515-60/65 [5]
A 516-60/65/70
A 106-B [5,6]
A 516-60/65/70 [9]
A 333-6
A 263-410S
A 264-304L/321
A 240-304L/316L/321
2b
Channel – head
(plate, pipe)
A 515-60/65 [5]
A 516-60/65/70
A 516-60/65/70 [9]
A 333-6
4a
Channel flange at
tubesheet
(forging)
Channel flange at cover
(forging)
A 105 [7,8,9]
A 266-Cl2 [7,9]
A 765-II [6]
A 263-410S
A 264-304L/316L/321
A 240-304L/316L/321
A 182 F304L/316L/321
A 105 [7,8,9]
A 266-Cl2 [7,9]
A 765-II [6]
5a
Stationary tube sheet
with u-tube or floating
head [3]
(forging, plate)
A 266-Cl2 [7,9]
A 515-70 (not
welded)
A 516-65/70
5b
Fixed tube sheets [3,4]
(forging, plate)
6
Floating tube sheet [3]
(forging, plate)
7
Floating head flange
(forging)
9
12
4b
Materials group
D
Copper alloys
E
Duplex
stainless steel
[2]
A 240 [2]
F
Alloy 400
(Monel)
G
Titanium
B 127N04400 [14]
B 265-Gr.2 [14]
As for channel
- shell
B 171-C61400 [14]
B 171-C71500 [14]
B 171-C63000 [14,15]
B 148-C95800
As for channel - shell
A 240 [2]
As for channel - shell
A 182-F51/F53
A 182 F304L/316L/321
As for channel - shell
A 182-F51/F53
A 765-II [6]
A 516-65/70 [6][9]
A 263-410S
A 264-304L/316L/321
A 240-304L/316L/321
A 182 F304L/316L/321
B 171-C61400 [14]
B 171-C71500 [14]
B 171-C63000 [14,15]
A 182-F51/F53
A 240 [2]
As for
channel –
shell
As for
channel shell
As for
channel shell
B 127N04400 [14]
A 266-Cl.2 [7,9]
A 515-70 (not
welded)
A 516-65/70
A 266-Cl2 [7,9]
A 515-70 (not
welded)
A 516-65/70
A 105 [7,8,9]
A 266-Cl2 [7,9]
A 765-II [6]
A 516-65/70 [6][9]
A 263-410S
A 264-304L/321
A 240-304L/316L/321
A 182 F304L/316L/321
A 263-410S
A 264-304L/321
A 240-304L/316L/321
A 182 F304L/316L/321
A 182 F304L/316L/321
B 171-C61400 [14]
B 171-C71500 [14]
B 171-C63000 [14,15]
A 182-F51/F53
A 240 [2]
B 127N04400 [14]
B 265-Gr.2 [14]
B 381-F-2
B 171-C61400 [14]
B 171-C71500 [14]
B 171-C63000 [15]
A 182-F51/F53
A 240 [2]
B 127N04400 [14]
B 265-Gr.2[14]
B 381-F-2
A 182-F51/F53
B 564N04400
B 381-F-2
B 367-C-2
Floating head (plate)
A 515-60/65 [5]
A 516-60/65/70
A 516-60/65/70 [9]
A 263-410S
A 264-304L/321
A 240-304L/316L/321
A 240 [2]
B 127N04400 [14]
B 265-Gr.2
B 367-C-2
Channel cover
(forging, plate)
A 266-Cl2 [7,9]
A 515-60/65 [5]
A 516-60/65/70
A 765-II [6]
A 515-60/65 [9]
A 516-60/65/70 [9]
A 263-410S
A 264-304L/316L/321
A 240-304L/316L/321
A 182-F304L/316L/321
B 283-C63000
B 148-C95800
B 369-C96200
B 369-C96400
B 171-C61400 [14]
B 171-C71500 [14]
B 171-C63000 [14,15]
B 148-C95800
B 369-C96200
B 369-C96400
B 171-C61400 [14]
B 171-C71500 [14]
B 171-C63000 [14,15]
A 182-F51/F53
A 240 [2]
B 127N04400 [14]
B 265-Gr.2 [14]
B 381-F-2
A 765-II [6]
A 516-65/70 [6][9]
A 765-II [6]
As for channel
- shell
As for channel
- shell
B 265-Gr.2 [14]
B 381-F-2
DEP 31.21.01.30-Gen.
February 2011
Page 59
Item
no.
A
Carbon steel
[1]
Component
B
Low temperature
carbon steel
16
Tubes
A 179
A 214 [10]
A 179
A 214 [10]
A 334-6
17
Nozzles – tube side
(pipe, forging)
A 106-B
A 105 [7,8,9]
A 266-Cl2 [7,9]
A 333-6
A 350-LF2 Cl.1
A 765-II [6]
18
Nozzle flange – tube
side (forging)
A 105 [7,8,9]
A 266-Cl2 [7,9]
21a
Cladding – channel side
21b
C
Stainless steel
Materials group
D
Copper alloys
A 268-TP405/410
A 213
TP304L/316L/321
A 249
TP304L/316L/321 [10]
A 312TP304L/316L/321
B 111-C70600 [16]
B 111-C71500 [16]
B 111-C71640 [16]
B 111-C68700 [16,17]
As for channel - shell
A 350-LF2 Cl.1
A 765-II [6]
A 182-F304L/316L/321
-
-
A 263-410S
A 264-304L/316L/321
Cladding – tube sheets
-
-
A 263-410S
A 264-304L/316L/321
21c
Cladding – floating head
-
-
A 263-410S
A 264-304L/316L/321
22
Baffles and support
plates (plate)
A 283-C
A 515-60/65
A 516-60/65/70
A 283-C
A 515-60/65
A 516-60/65/70
A 240-405/410S
A 240-304/316/321
24
29
30
31
32
33
34
Eye bolt/loosening bolts
Expansion bellows
(internal)
Bearing ring (plate)
Internal set of screws of
bearing ring
Test ring/flange
Sacrificial plates/anodes
Reducer construction
(plate, pipe)
E
Duplex
stainless steel
[2]
A 789 [2]
F
Alloy 400
(Monel)
G
Titanium
B 163N04400
B 338-Grade 2
A 790 [2]
As for
channel shell
As for channel - shell
A 182-F51/F53
As for
channel shell
As for channel
– shell, or A
105 with Ti
Gr.2 lap
As for channel
- shell
B 171-C61400 [14]
B 171-C71500 [14]
B 171-C63000 [14,15]
B 171-C61400 [14]
B 171-C71500 [14]
B 171-C63000 [14,15]
B 171-C61400
B 171-C71500
B 171-C63000 [15]
A 283-C [18]
B 171-C61400
B 171-C63000
-
B 127N04400 [14]
B 265-Gr.1 [14]
-
B 127N04400 [14]
B 265-Gr.1 [14]
-
B 127N04400
B 265-Gr.2
A 240-304/316
A 240 [2]
B 127N04400
A 283-C [18]
A 516-60/65/70
[18]
A 193-B7
[11]
A 193-B7
[11]
A 193-B7
[11]
A 193-B7
[11]
A 193-B7
[11]
A 193-B7
[11]
B 127-N04400
B 265-Gr.2
A 193-B7
[11]
A 283-C
A 675-45/50/55
A 193-B7/B7M
A 283-C
A 675-45/50/55
A 193-B7/B7M
A 283-C
A 675-45/50/55
A 193-B7,B6X, B7M
A 283-C
A 675-45/50/55
A 193-B7/B7M
A 283-C
A 675-45/50/55
A 193-B7/B7M
-
A 193-B7/B7M
Carbon steel
Zn, Mg [12,13]
A 105 [7,8,9]
A 106-B
Carbon steel
-
Carbon steel
A 387-5/9
A 240-TP405/410S
Carbon steel
Soft iron [19]
B 171-C63000
Carbon steel
-
A 193B7/B7M
Carbon steel
-
Carbon steel
B 861
DEP 31.21.01.30-Gen.
February 2011
Page 60
ITEM LIST AND NOTES FOR TABLE 1-2
Item
No.
1
2a
2b
3
4a
4b
5a
5b
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21a
21b
21c
NOTES:
Pressure parts
Shell
Channel - shell
Channel - head
Shell flange - channel side
Channel flange - tubesheet
Channel flange - cover
Fixed tube sheet
Stationary tube sheet
Floating tube sheet
Floating head flange
Clamp ring
Floating head
Cover - shell
- head
- flange
Shell flange - cover side
Channel cover
Gasket - shell side/shell cover
- floating head
- tube side/channel cover
Stud bolt and nuts
Stud bolt and nuts for floating
head
Tubes
Nozzles – tube side
Nozzle flange - tube side
Split key ring (chem. service)
Key ring flange (chem. service)
Cladding/ lining - tube side
Cladding/ lining - tube sheets
Cladding/ lining - floating head
Item
No.
22
23
24
25
26
27
28
29
30
31
32
33
Non-pressure parts
Baffles and support plates
Seal strips, bars/rods,
spacers,
strips
Eye bolts/loosening bolts
Weir plates
Saddle/brackets
Sliding plate
Reinforcing ring for floating
head
Expansion bellows (internal)
Bearing ring
Internal set screws of bearing
ring
Test ring/flange
Sacrificial plates/anodes
Item
No.
34
35
Other items
Reducer construction
Stub ring
1. For carbon steel exchangers in sour or wet hydrogen sulphide service, refer to DEP 31.22.20.31-Gen.
2. UNS S31803, UNS S32205, UNS S32750, UNS S32760.
3. Matching tube-tubesheet compositions are required, unless otherwise specified.
4. If the tubesheet forms a flange or is directly welded to the shell it shall be supplied as a forging and not as
plate material.
5. C-content max. 0.23 % for carbon steel.
6. Mn < 1.3 %.
7. C < 0.25 %.
8. Mn < 1.2 %.
9. Normalised.
10. Welded tubes may be used only when specified on the data/requisition sheet.
11. Bellows material shall be identified on the data/requisition sheet, and requires approval of the Principal.
12. Composition of sacrificial anodes are given in DEP 30.10.73.10-Gen.
13. For correct mounting of Mg and Zn anodes refer to drawing S 21.072.
14. Clad plate may be used when specified on the data/requisition sheet. When Titanium cladding is applied,
B 265 Gr.1 clad material shall be used.
15. Recommended grade for seawater service.
16. Tubes provided with low-fins shall be ordered according to ASTM B 359 or EN 12452.
17. Al brass tubes (bare or low-finned) shall only be used in the fully annealed condition and shall be capable of
meeting the requirements of the stress corrosion susceptibility tests (as in ASTM B 154, B 858, ISO 196 or
ISO 6957).
18. Only for non-corrosive non-aqueous service.
19. Required for C68700 tubes. For correct mounting of Fe anodes refer to drawing S 21.073.
DEP 31.21.01.30-Gen.
February 2011
Page 61
Figure 1-1:
Type A, Floating head heat exchanger
Type B, Hairpin or U-tube heat exchanger
Type C, Fixed tube sheet heat exchanger
DEP 31.21.01.30-Gen.
February 2011
Page 62
Figure 1-2:
Type A, Vertical reboiler, floating head
Type B, Vertical reboiler, fixed tube sheet
Type C, Kettle type reboiler, floating head
Type D, Kettle type reboiler, hairpin bundle
DEP 31.21.01.30-Gen.
February 2011
Page 63
Floating tube sheet with anodes (tube side)
Figure 1-3:
Fixed tube sheet with anodes (tube side)
DEP 31.21.01.30-Gen.
February 2011
Page 64
APPENDIX 2
METHOD OF DETECTION OF HARMFUL OXIDE FILMS ON COPPER-NICKEL
ALLOY TUBES
Applicable to all grades of copper nickel tubes
(ASTM B 111, ASTM B 359, EN 12451 and EN 12452)
1.0
GENERAL
Informative: A Cu-Ni tube will passivate rather slowly. Generally, it will take a week before
the surface is protected. In the meantime, pitting may occur under severe operating
conditions. One reason may be that part of the tube is covered with cathodic oxides. To
verify this, a measuring method has been developed. The principle of the method is to
compare the corrosion (rest) potential Eacorr of freshly abraded tube alloy with the rest
potential Etcorr of the tube bore in the as-received condition. The difference, ∆E, Etcorr - Eacorr,
is a measure of the "nobility" of films on the tube bore surface. The larger the difference,
the more cathodic is the tube. A clean, acceptable tube left in the atmosphere will develop
an oxide film, which can be up to +0.070 volts cathodic compared to the bare material.
Therefore, the criterion for acceptance has been taken as ∆E < +0.070 volts.
The test shall be carried out by the tube supplier as part of the final quality control
procedure. When the tubes are ordered according to ASTM B 111 or ASTM B 359, one (1)
tube shall be tested per lot. When the tubes are ordered according to EN 12451 or
EN 12452, the number of tubes to be tested shall be in accordance with the sampling rate
table given in those standards.
2.0
PROCEDURE
2.1
Cleaning
Prior to testing, the tube should be degreased thoroughly by pulling a soft cloth, soaked in a
petroleum spirit, through the tube and repeating this until the cloth is clean. Allow the
solvent to evaporate. The potential Etcorr is noted 10 minutes after inserting the reference
electrode.
2.2
Filling with KCl
One end of the tube is plugged with a rubber stopper and, with the tube either vertical or
inclined, it is filled with a potassium chloride solution. To enable the steady-state potential
to be reached quickly a dilute solution of potassium chloride (0.02 M or approximately
1.5 g/l) shall be used to fill the tube. Potentials shall be measured against silver/silver
chloride reference electrode, also in 0.02 M KCl solution, so avoiding liquid junction
potentials.
2.3
Measuring potential of "as delivered condition"
Without undue delay the reference electrode, removed from its storage capsule, is carefully
lowered into the tube to dip into the solution, so completing the circuit via high impedance
millivolt meter, such as Fluke Model 8000 A. (The connections to the meter are: reference
electrode to the ground (or black) terminal tube/crocodile clip (kept dry) to the positive (red)
terminal.).
Note:
2.4
It is important to prevent the solution wetting either the tube exterior/crocodile clip junction or a freshly
cut end of the tube since either possibility will result in false readings.
Measuring potential of "bare material"
To obtain the value for the freshly abraded tube alloy a piece of tube is stoppered as before
with a rubber bung and the outer surface of the tube is abraded with silicon carbide paper
under clean water to obtain a bright surface. This is rinsed first with clean water and then
with the potassium chloride (KCl) solution (0.02 M) before being immersed in fresh KCl
solution into which the reference electrode is placed. A crocodile clip is attached to a dry
portion of the tube and the potential Eacorr noted after 10 minutes.
DEP 31.21.01.30-Gen.
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3.0
INTERPRETATION OF RESULTS
For ASTM B111-C71640 or EN 12451-CW353H alloy repeated measurements of many
tubes have shown that Eacorr determined by this method is -0.230 ± 0.010 volts.
An acceptable tube has the difference,
where
∆E
=
Etcorr
E, below +0.070 Volts
- (-0.230) volts,
e.g. for an acceptable tube Etcorr may be found to be -0.180 Volts
so that
∆E
= -0.180 - (-0.230)
= +0.050 volts
whereas for an unacceptable tube Etcorr would be more positive than -0.160 volts.
4.0
REMOVAL OF AN UNACCEPTABLE CATHODIC OXIDE FILM
Removal of an unacceptable cathodic film (∆E > +0.07 Volts) may be done by either blast
cleaning or acid cleaning. After cleaning the test shall be repeated on representative
samples.
5.0
CERTIFICATION
Manufacturers shall issue certificates showing that each (inspection) lot of tubes supplied is
free of harmful films.
DEP 31.21.01.30-Gen.
February 2011
Page 66
APPENDIX 3
DRAWINGS
Figure 3-1
Eye Bolt Hole for Clad Tubesheets
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