Materials System Specification
27 December 2021
02-SAMSS-005
Carbon Steel and Low Alloy Butt Welding Pipe Fittings
Document Responsibility: Materials Engineering Standards Committee
Previous Revision: 06 November 2019
Contact: (MUAILISM)
©Saudi Aramco 2021. All rights reserved.
Saudi Aramco: Company General Use
Next Revision: 27 December 2026
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Document Responsibility: Materials Engineering Standards Committee
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Carbon Steel and Low Alloy Butt Welding Pipe Fittings
Contents
Summary of Changes.................................................................................................... 3
1
Scope ................................................................................................................... 4
2
Conflicts and Deviations ....................................................................................... 5
3
References ........................................................................................................... 5
4
Purchase Order Information ................................................................................. 8
5
Design .................................................................................................................. 8
6
Materials ............................................................................................................. 11
7
Welding .............................................................................................................. 14
8
Heat Treatment .................................................................................................. 16
9
Inspection and Testing ....................................................................................... 17
10
Additional Requirements for Hydrogen Service .................................................. 22
11
Positive Material Identification (PMI) .................................................................. 22
12
Product Marking, Coating, Packing, and Documentation ................................... 22
document History ........................................................................................................ 23
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Carbon Steel and Low Alloy Butt Welding Pipe Fittings
Summary of Changes
Paragraph Number
Change Type
(Addition, Modification, Deletion,
New)
Technical Change(s)
Previous Revision
Current Revision
(6 November 2019)
(27 December 2021)
Title
Title
Modification
The title was changed to
include low alloys
1
1
Modification
NA
1.4
Addition
The scope was modified to
inlcude low alloys including CrMo and Ni-steel alloys.
Clarification about lateral tee
requirements
1.6
1.7
Modification
NA
5.7
Addition
NA
6.3
Addition
NA
6.4
Addition
NA
6.9
Addition
6.5
6.10
Clarification
NA
6.11
Addition
NA
6.12
Addition
Barred Tees
NA
6.13
Addition
Forged Fittings
NA
9.3.3
Addition
Lot defenition
NA
9.6.2
Addition
NA
9.7
Addition
Charpy V-nothch impact test
requirements for WPL6,
WPL9, WPL3 and WPL8
materials
NDE for forgings and hot
rolled bars
NA
10
Addition
Additional Requirements for
Hydrogen Service
NA
11
Addition
Positive Material Identification
(PMI)
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Clarification for forged product
requirements were removed
from this section and moved to
6.13
Addition of new clarification
about segmental and mitered
elbows.
ASTM A420 Low Temperature
Ni-Steel grades including
grades WPL6, WPL9, WPL3
and WPL8.
ASTM A234 Low Alloy Steel
(Cr-Mo)
Sour service requirements as
per NACE MR0175 / ISO
15156
Sour Service requirements for
starting plates and welded
pipe materials.
Sour Service requirements for
starting seamless pipes.
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Carbon Steel and Low Alloy Butt Welding Pipe Fittings
1
Scope
1.1
This specification is applicable to carbon steel, low temperature carbon steel
and low alloy (Cr-Mo and Ni-Steel) pipe fittings manufactured in accordance
with ASTM A234, ASTM A420 and MSS SP-75 for high strength fittings. This
standard only applies to fittings that are purchased “loose.” This Specification
does not apply to fittings installed on equipment that is engineered,
manufactured, and tested prior to delivery to Saudi Aramco unless specifically
invoked in the Purchase Order.
1.2
Cast fittings, stainless steel and corrosion-resistant alloy pipe fittings, and pipe
bends with a radius greater than three times the diameter (3D) are excluded
from the scope of this specification. Induction bends that have a radius 3D and
larger, and are not under ASME B16.9, are not under by this standard. They
are addressed in 01-SAMSS-039.
1.3
This standard applies to fittings meeting the requirements of ASME B16.9, MSS
SP-75, and special designed fittings such as Integrally-reinforced branch
connections (O-Lets) as per MSS SP-97.
1.4
Fabricated lateral tees are not covered by this specification. Fabricated lateral
tees shall be designed as per SAES-L-110 and manufactured as pipes spools
as per 01-SAMSS-010.
1.5
Socket-welding and threaded fittings per ASME B16.11 are excluded from this
specification.
1.6
Fittings purchased to this specification are suitable for use in accordance with
ASME B31.3, B31.4 or B31.8.
Note:
“Butt welding fittings” are fittings with beveled ends that connect into the piping system by butt
welds as detailed in ASME B16.9. “Welded fittings” refers to fittings that are fabricated from
plate and are assembled by welding or fittings made from a pipe fabricated by welding.
1.7
All fitting manufacturers shall perform forming, machining and heat treatment
operations either in-house or in a wholly owned subsidiary approved by Saudi
Aramco. It is not permitted to outsource forming, machining, welding or heat
treatment operations. Fitting manufacturers are not permitted to procure rough
products for further processing. For forged fitting products, the requirements
are detailed under paragraph 6.13 for “Forged Products”.
Note:
“For all materials: At the time of quotation, the fitting supplier shall include a statement for
country of origin, if other than the point of shipment. Traceability of finished materials shall
extend back to the original raw material source.”
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Carbon Steel and Low Alloy Butt Welding Pipe Fittings
2
Conflicts and Deviations
Any conflicts between this document and other applicable Mandatory Saudi
Aramco Engineering Requirements (MSAERs) shall be addressed in writing to
the EK&RD Coordinator.
Any deviation from the requirements herein shall follow internal company
procedure SAEP-302, Waiver of a Mandatory Saudi Aramco Engineering
Requirement.
3
References
All referenced specifications, standards, codes, drawings, and similar material
are considered part of this Material System Specification to the extent specified,
applying the latest version, unless otherwise stated.
3.1
Saudi Aramco References
Saudi Aramco Engineering Procedure
SAEP-302
Waiver of a Mandatory Saudi Aramco Engineering
Requirement
Saudi Aramco Engineering Standard
SAES-A-206
Positive Material Identification
SAES-L-110
Limitations on Pipe Joints and Components
Saudi Aramco Materials System Specifications
01-SAMSS-010
Fabricated Steel Piping.
01-SAMSS-016
Qualification of Plates for Pressured Equipment and
Storage Tanks for Resistance to Hydrogen-induced
Cracking
01-SAMSS-035
API Line Pipe
01-SAMSS-039
Induction Pipe Bends
01-SAMSS-043
ASTM Carbon Steel and Low Alloy Pipes for On-plot
Applications
02-SAMSS-011
Forged Steel and Alloy Flanges
Saudi Aramco Inspection Requirements
Form 175-026100
Fittings: Carbon steel, high strength, low temperature and
low alloys.
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Carbon Steel and Low Alloy Butt Welding Pipe Fittings
3.2
Industry Codes and Standards860
American Society of Mechanical Engineers
ASME B16.9
Factory-made Wrought Steel Buttwelding Fittings
ASME B16.25
Butt Welding Ends
ASME B31.3
Process Piping
ASME B31.4
Liquid Petroleum Transportation Piping Systems
ASME B31.8
Gas Transmission and Distribution Piping Systems
ASME B31.12
Hydrogen Piping and Pipelines
ASME SEC II
Part CSpecification for Welding Rods, Electrodes, and
Filler Metals
ASME SEC VIII
Rules for Construction of Pressure Vessels
ASME SEC IX
Qualification Standard for Welding and Brazing
Procedures, Welders, Brazers, and Welding and Brazing
Operators
American Society for Testing and Materials
ASTM A105
Standard Specification for Carbon Steel Forgings for Piping
Applications
ASTM A182
Standard Specification for Forged or Rolled Alloy steel Pipe
Flanges, Forged Fittings and Valves and Parts for High
Temperature Service
ASTM A234/A234M Standard Specification for Piping Fittings of Wrought
Carbon Steel and Alloy Steel for Moderate and Elevated
Temperatures
ASTM A350
Standard Specification for Carbon and Low-alloy Steel
Forgings, Requiring Notch Toughness Testing for Piping
Components
ASTM A370
Standard Test Methods and Definitions for Mechanical
Testing of Steel Products
ASTM A388
Standard Practice for Ultrasonic Examination of Steel
Forgings
ASTM A420
Standard Specification for Piping Fittings of Wrought
Carbon Steel and Alloy Steel for Low- Temperature Service
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Carbon Steel and Low Alloy Butt Welding Pipe Fittings
ASTM A578
Straight-Beam Ultrasonic Examination of Rolled Steel
Plates for Special Applications
ASTM A707
Standard Specification for Forged Carbon and Alloy Steel
Flanges for Low-Temperature Service
ASTM A833
Practice for Indentation Hardness of Metallic Materials by
Comparison Hardness Testers
ASTM A860/A860M Standard Specification for Wrought High-Strength Ferritic
Steel Butt-Welding Fittings ASTM A960 Standard
Specification for Common Requirements for Wrought Steel
Piping Fittings
ASTM A788
Standard Specification for Steel Forgings, General
Requirements
ASTM E10
Standard Test Method for Brinell Hardness of Metallic
Materials
ASTM E92
Test Method for Vickers Hardness of Metallic Materials
ASTM E165
Standard Test Method for Liquid Penetrant Examination
American Welding Society
AWS A5.XX
Specifications for Welding Filler Metals (Series of
Specifications)
Manufacturers Standardization Society
MSS SP-75
High-Strength, Wrought, Butt-Welding Fittings
MSS SP-97
Integrally Reinforced Forged Branch Outlet Fittings –
Socket Welding, Threaded, and Buttwelding Ends
NACE International
NACE MR0175
/ISO 15156 Petroleum, Petrochemical, and Natural Gas
Industries-Materials for use in H2S-Containing
Environments in Oil and Gas Production
European Norm
EN10204
Metallic products - Types of inspection documents
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Carbon Steel and Low Alloy Butt Welding Pipe Fittings
4
Purchase Order Information
The following information shall be included in the Purchase Order:
a)
Type of fitting
b)
Nominal size of fitting
c)
Grade or specified minimum yield strength of fitting material
d)
Nominal size, wall thickness, or schedule and end details of
pipe to be matched
e)
Sour Service, if applicable
f)
Material specification of matching pipe
g)
Wall thickness of lap-joint stubs; if applicable
h)
Additional material and testing requirements; if applicable
i)
Charpy impact testing requirements, if applicable
j)
Export packing, marking, and shipping details
k)
Hydrogen Service as per ASME B31.12, if applicable.
5
Design
5.1
Pressure Rating
5.1.1
Design and pressure rating of ASTM A234 and ASTM A420 fittings
shall be established by proof testing per ASME B16.9 Section 9 or by
mathematical stress analysis per ASME B31.3 Section 304.
5.1.2
Design and pressure rating of MSS SP-75 fittings shall be established
by proof testing per MSS SP-75 or by mathematical stress analysis per
ASME B31.3 Section 304.
5.1.3
A drawing will be prepared for all fittings showing the overall
dimensions including the required thicknesses in all areas. This
drawing will be available to the Saudi Aramco inspector. Design
calculations and proof testing data shall be available on request. No
portion of the fitting shall have thickness less than the minimum
specified thickness.
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Carbon Steel and Low Alloy Butt Welding Pipe Fittings
5.2
Main Dimensions
The pipe fittings covered by this specification shall have dimensions as
specified in ASME B16.9 or MSS SP-75 as applicable. Pressure rating of
fittings not meeting the standards dimensions shall be established per the
requirements of Section 5.
Any exceptions shall be indicated in the Purchase Order.
5.3
Starting Pipe (Mother Pipe)
For fittings made from pipes, the starting pipe (mother pipe) shall not be resized
by cold or hot expansion, reduction or drawing prior to the forming process by
the fitting manufacturer.
5.4
Circumferential Welds
Circumferential welds are not allowed except to attach extensions such as
those mentioned in paragraph 5.5. Circumferential welds are never allowed in
the crotch area of fittings.
5.5
Tees and Reducing Tees
The branch outlet of tees shall be extruded or forged to the run and shall have a
smoothly curved transition between run and branch. When tees are fabricated
from plate, the weld seams shall be parallel to the axes of the run and the
branch.
Note:
Welded-on branch connections (set-on or stub-in) are not considered tees as per ASME B
16.9 and are not covered by this standard. These can be designed as per SAES-L-110 and
fabricated as per 01-SAMSS-010 as pipe spools.
Lengthening of an extruded outlet by means of a circumferential weld in the cylindrical part of
the branch is permitted if specified in the PO.
5.6
Reducers
Concentric and eccentric reducers shall have smoothly curved wrought
transitions and parallel ends (ASME shape) unless a conical shape has been
specified in the Purchase Order.
Reducers shall have a nominal wall thickness which is at least equal to the
specified nominal wall thickness of the matching pipe (of equal specified
minimum yield strength) at the large end.
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Carbon Steel and Low Alloy Butt Welding Pipe Fittings
ASME shape reducers not listed in ASME B16.9 or MSS SP-75 shall be
designed in accordance with ASME B31.3, paragraph 304.6 for a design
pressure permitted by the matching pipe.
Conical reducers are only permitted when so specified in the Purchase Order.
The included angle shall not exceed 12 degrees.
Exception:
An included angle of maximum 15 degrees is allowed when the reducer is concentric, has two
cylindrical ends with a minimum length of 50 mm, and smoothly finished circumferential
welds.
5.7
Elbows
Factory-made segmental elbows (elbows with customized angle requirements)
when specified in the P.O. shall meet ASME B16.9 requirements. The elbow
beveled-ends shall satisfy the dimensional and roundness requirements.
Beveled ends inspection requirements in sections 6.5 and 9.3 shall apply.
Mitered elbows, also known as mitered bends, (elbows made by joining pipe
ends) or elbows made of multiple sections are not covered by this standard.
5.8
Lap-Joint Flange Stub Ends
The wall thickness of stub ends for lap-joint flanges shall be as specified in the
Purchase Order and the welding end prepared by internal taper boring to match
the specified pipe. Lap-joint flange stub ends (weld ends) for sizes larger than
NPS 24 are covered by 02-SAMSS-011 and related standard drawings.
5.9
Special Designs
Special designs, such as nonstandard shapes and dimensions, will be
considered when the Vendor can prove that similar fittings have been
successfully tested by means of an actual proof test and/or mathematical
analysis in accordance with ASME B16.9 or MSS SP-75. The design shall be
reviewed by Saudi Aramco.
5.10
Butt Welding Ends
Unless otherwise specified in the Purchase Order, the butt welding ends shall
be in accordance with the requirements of ASME B16.25 and match the
beveled end of the pipe specified in the Purchase Order.
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Carbon Steel and Low Alloy Butt Welding Pipe Fittings
6
Materials
6.1
General
For carbon steel products, boron content shall be shown in the heat analysis or
product analysis and shall not exceed 0.0005%. Also, boron shall not be
intentionally added to any other grade.
For carbon steel products, the carbon equivalent shall not exceed 0.42% when
calculated according to the formula:
CE (IIW) = C +
6.2
6.3
Mn (Cr + Mo + V) ( Ni + Cu)
+
+
6
5
15
(1)
ASTM A234 Carbon Steel
6.2.1
Carbon steel material shall conform to the requirements of ASTM
A234/A234M Grade WPB or ASTM A420 Grade WPL6.
6.2.2
The hardness for Grade WPB shall not exceed 197 HBW.
ASTM A420 Low Temperature Steel (Ni Alloy Steels)
6.3.1
Low temperature steel materials, including Ni-Steels, shall conform to
the requirements of ASTM A420/A420M Grades WPL6, WPL9, WPL3
or WPL8.
6.3.2
The hardness for Grade WPL6 shall not exceed 197 HBW.
6.4
ASTM A234 Low Alloy Steel (Cr-Mo alloy steel)
6.5
High strength fittings shall not be substituted for WPB or WPL6 fittings.
High strength starting stock shall not be used for Grade WPB/WPL6
fittings. In no case shall the actual yield strength of the finished
WPB/WPL6 fittings exceed 440 MPa (63,817 psi). All other
requirements for WPB/WPL6 fittings shall be met.
6.6
ASTM A234 and ASTM A420 Fittings shall conform to ASTM A960
Supplementary Requirements S50 “Product Analysis,” S51 “Tension
Test” and S57 “Hardness Test.”
Note:
For Supplementary Requirement S50, a heat analysis may be substituted for the product
analysis except for welding material.
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Carbon Steel and Low Alloy Butt Welding Pipe Fittings
6.7
6.10
High Strength Fittings (specified minimum yield strength ≥ 42,000 psi)
6.7.1
With the exception of the chemical composition requirements in
paragraph 6.7.3 below, the high strength material shall conform to the
requirements of MSS SP-75, including Supplementary Requirements
SR-4 (fitting intended for sour service), SR-5 (actual yield strength
limitation), and SR-10 (more restrictive chemical requirements and
carbon equivalent).
6.7.2
Base material and welds shall have a maximum hardness of
235 HBW (248 HV).
6.7.3
Chemical composition shall be in accordance with the requirements of
ASTM A860/A860M, paragraph 7. The carbon equivalent of the base
metal shall not exceed 0.42 %.
6.7.4
Weld metal shall have a nickel content of less than 1%, unless
specified.
6.8
The vendor shall provide a certified material test report listing the actual
results of the chemical analysis (product analysis), mechanical
properties, notch toughness properties, heat treatment, nondestructive
examination, and any special tests required by the Purchase Order.
6.9
For Sour service, the final products shall comply with the requirements
of NACE MR0175 / ISO 15156. The sulfur content shall not exceed
0.003% for plates, welded and seamless pipes and 0.015% in forgings.
For Sour service, the following additional requirements are applicable to the
starting plates and welded pipe materials for welded fittings.
6.10.1 The starting LSAW pipe or plates that are not intentionally
manufactured as HIC resistant shall not be used.
6.10.2 All starting plates or LSAW pipes shall be 100% UT examined for
laminations in accordance with ASTM A578 with acceptance criteria as
per S1, S2.1.
6.10.3 Plates shall be HIC qualified in accordance with 01-SAMSS-016. Steel
that passes the HIC test, but has not been initially manufactured to be
HIC resistant steel shall not be used.
6.10.4 Welded (LSAW) pipe shall be HIC qualified in accordance with 01SAMSS-035 or 01-SAMSS-043 as applicable.
6.10.5 Butt welding fittings made from HIC resistant plates or welded pipes
shall be furnished in the normalized and tempered or quenched and
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Carbon Steel and Low Alloy Butt Welding Pipe Fittings
tempered (for high strength grades) condition. Tempering temperature
shall be 610°C ± 10°C, 1 hour/1 inch or as recommended by the steel
mill. The final mechanical properties shall meet the specification
requirements.
Note:
Some steel makers qualify HIC-resistant steel in the as-PWHT or as-tempered condition only.
Hence, delivering the final fitting in normalized condition may not guarantee HIC resistance
properties.
6.13
6.11
For sour service, Seamless mother pipe materials are not required to
be HIC tested if the pipes are procured from a Saudi Aramco approved
source.
6.12
Barred tees shall be manufactured in accordance with the applicable
specification. The mesh material shall be equivalent to the tee material.
Fabrication activities shall be completed before the final heat treatment
process. Fillet welds shall be inspected by Dye Penetrant Testing.
Forged fittings or Integrally-reinforced branch connections (O-Lets) as per MSS
SP-97 shall be either forged by the manufacturer or machined from hot rolled
bars. The following additional requirements are applicable to the starting
material.
6.13.1 Carbon steel ASTM A105 for normal and moderate temperature or
A350 LF2 for low temperature shall be used. For high strength, ASTM
A350 LF6, A707 L3 or L5 shall be used. Sulfur shall be less than
0.015% and Carbon Equivalent shall be less than 0.42%. The material
shall conform to the requirements of ISO 15156 /NACE MR0175. The
material shall be delivered in normalized or normalized and tempered
or quenched and tempered condition.
6.13.2 For low alloy forgings, ASTM A182 grade F11, F22, F5, F9 or F91 shall
be used or as specified in the PO.
6.13.3 The minimum forge reduction ratio shall be 4:1.
6.13.4
For bar with outside diameter greater than 100 mm (4 in), the tensile
and set impact test specimens shall be taken in both axial and
tangential direction of the bar.
6.13.5 Surface inspection shall be carried out by magnetic particles with
acceptance criteria as per the inspection requirements in this
specification.
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Carbon Steel and Low Alloy Butt Welding Pipe Fittings
6.13.6
Volumetric inspection by ultrasonic examination shall be carried out
with acceptance criteria as per the inspection requirements in this
specification.
6.13.7 Material shall be fully traceable to melt and heat treatment lot with
inspection requirement as per EN10204 “type 3.1”. The hot rolled bar
manufacturer shall be an approved supplier by the fitting manufacturer.
7
Welding
7.1
General
7.2
7.1.1
Complete Welding Procedure Specifications (WPS's) and Procedure
Qualification Records (PQR's) shall be made available for review by the
Saudi Aramco inspector.
7.1.2
All Welding Procedure Specifications (WPS's) and Procedure
Qualification Records (PQR's) shall be written in English and conform
to the applicable Code.
7.1.3
Welding procedures shall be written and qualified in accordance
ASME SEC IX or other comparable international code.
7.1.4
Welders and welding operators will be qualified in accordance with
ASME SEC IX or other comparable international code.
7.1.5
The welds in the starting pipe (LSAW pipes) shall be qualified in the
final fitting heat treatment condition.
Processes
7.2.1
The following processes are approved for use:
•
Shielded Metal Arc Welding (SMAW)
•
Gas Tungsten Arc Welding (GTAW)
•
Submerged Arc Welding (SAW)
•
Gas Metal Arc Welding (GMAW) - Short Circuiting transfer shall
not be used.
•
Flux Core Arc Welding (FCAW) - Shall not be used for the root
pass on single sided groove welds.
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Carbon Steel and Low Alloy Butt Welding Pipe Fittings
7.2.2
7.3
7.4
Welding without the addition of filler material is not permitted.
Welding Consumables
7.3.1
Electrodes, filler wires, and fluxes shall conform to the requirements of
the BPV, ASME SEC II, Part C, identical to the AWS A5.XX
specification series. Other consumables may be used only with the
specific approval of Saudi Aramco.
7.3.2
Properly conditioned low-hydrogen electrodes shall be used for all
fittings when the wall thickness exceeds 13 mm.
7.3.3
A change in filler metal deposit chemistry from A-No. 1 of BPV,
ASME SEC IX to A-No. 2 and vice-versa is not permitted without
requalification.
7.3.4
Active Submerged Arc Welding fluxes shall not be used.
7.3.5
Shielding gases shall conform to the appropriate Compressed Gas
Association (CGA) specification(s).
Welding Procedure Qualifications
7.4.1
General
For SAW flux, the specific brand and type shall be the same as used
for the PQR. For FCAW electrodes the specific brand, type and
maximum size shall be the same as used for the PQR. The brand
name and type of flux FCAW electrode shall be specified on both the
WPS and PQR.
7.4.2
Hardness Testing
Hardness measurements conducted in accordance with ASTM E92
shall be made on a full-thickness, transverse cross-section of the weld
that has been mounted, polished to metallographic quality, and etched.
Two indentations shall be made. One shall be within 1.0 mm from the
O.D. surface and one within 1.0 mm from the I.D. surface. Each
traverse shall consist of at least two hardness indentations in each of
the following locations:
a)
Weld metal
b)
Heat affected zone on each side of the weld, and
c)
Parent metal on each side of the weld.
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Carbon Steel and Low Alloy Butt Welding Pipe Fittings
Only Vickers 5 kg or 10 kg hardness testers shall be used. Hardness
of base metal, HAZ, and weld metal shall not exceed 207 HV for Grade
B fittings and 250 HV for high strength fittings.
7.5
8
Repairs
7.5.1
Cracks, other than crater cracks, shall be repaired only if approved by
the Saudi Aramco inspector. The repair procedure shall be approved
by the Consulting Services Department.
7.5.2
Unsuccessful weld repairs after the second attempt shall be completely
cut out and replaced.
Heat Treatment
Heat treatment after all forming and welding processes are completed is
required for all fittings.
Note:
Cold sizing after heat treatment shall be avoided or minimized to 1% maximum of the fitting
circumference. The cold sized area shall be subjected to proper volumetric and surface NDE.
8.1
All grade WPB fittings supplied in accordance with this specification shall be
normalized as defined in ASTM A234 unless approved. A heat treatment above
the critical temperature is required for all fittings after forming except as
permitted in 8.2. Stress relief heat treatments are not acceptable, even if
permitted in ASTM A234 / A234M, ASTM A420 or in MSS SP-75. A stress
relief heat treatment is only permitted after the weld assembly of heat treated
components under A234.
Note:
Fittings will be formed, welded and heat treated following one of the following four schedules:
A, B or C
A.1 Hot or cold forming
A.2 Heat treatment above critical temperature except as permitted in 8.2
B.1 Hot or cold forming
B.2 Heat treatment above critical temperature
B.3 Weld assembly
B.4 Heat treatment above critical temperature except stress relief is permitted for ASTM
A234
C.1 Hot or cold forming
C.2 Weld assembly
C.3 Heat treatment above critical temperature
8.2
Seamless ASTM A234 Grade WPB fittings for which the final forming
operation is completed at a temperature above 620°C and below
980°C need not be subsequently heat treated provided they are cooled
in still air. This is not applicable to barred tees.
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Carbon Steel and Low Alloy Butt Welding Pipe Fittings
8.3
Hot formed high strength fittings shall be cooled below the lower critical
temperature prior to heat treatment.
8.4
Cold formed starting pipes shall receive an intermediate annealing heat
treatment prior to subsequent cold forming stages.
8.5
Fittings that require multiple cold forming steps shall receive an
intermediate annealing heat treatment prior to the subsequent cold
forming step.
9
Inspection and Testing
9.1
General
The fittings are subject to inspection by the Saudi Aramco Inspection
Representative per Saudi Aramco Inspection Requirement Form 175-026100
attached to the Purchase Order.
Required NDE is to be done after completion of manufacturing processes.
9.2
Visual Examination and Dimensional Check
100% of fittings will be visually inspected for general appearance, workmanship.
Fit-up shall be acceptable in accordance with ASME B31.3 Paragraph 344.2.
Weld surfaces shall show a smooth contour. Dimensions of the fitting shall be
checked against ASME B16.9, MSS SP-75 or approved Vendor's Drawings.
9.3
Dye Penetrant or Magnetic Particle Testing
9.3.1
9.3.2
Butt weld ends shall be 100% tested using one of the following
methods:
●
Dye penetrant (color contrast penetrant) in accordance with
ASTM E165. Acceptance criteria shall be per “Boiler &
Pressure Vessel Code,” ASME SEC VIII D1, Appendix 8.
●
Magnetic particle tested in accordance with ASME SEC VIII
D1, Appendix 6.
Full body (OD and ID) inspection using LPT or MPT shall be conducted
on fittings with the frequency indicated in Table 1.
Table 1 - Sampling Plan Based on Lot Size
Size Lot Size
Sample Size
2–8
2
9 – 15
3
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Carbon Steel and Low Alloy Butt Welding Pipe Fittings
16 – 25
5
26 – 50
8
51 – 90
13
91 – 150
20
151 – 280
32
281 – 500
50
501 – 1200
80
1201 – 3200
125
For any sample that fails the acceptance criteria, the entire fittings from
the same heat/lot shall be tested.
9.3.3
A lot shall consist of all fittings of the same type, size, and wall
thickness, manufactured from one heat of material (and, if fabrication
welding is performed using one lot number of electrode or one heat of
weld wire), and heat treated using the same heat-treat cycle in either a
continuous or batch-type furnace controlling within a range of 25 °F [14
°C] and equipped with recording pyrometers so that complete records
of heat treatment are available.
9.4
Radiography
All welds in fabricated fittings shall be 100% radiographed in
accordance with “Boiler and Pressure Vessel Code,” ASME SEC VIII
D1, paragraph UW-51.
9.5
Production Hardness Tests
9.5.1
Hardness tests shall be conducted on a minimum of 20% of seamless
fittings formed at temperatures above 620°C and 100% of seamless
fittings formed at 620°C or lower. Hardness tests shall be conducted
on 100% of all welded construction fittings regardless of forming
temperature.
9.5.2
Hardness testing shall be conducted using either a bench-top hardness
tester calibrated to ASTM standard hardness test blocks as per ASTM
E10 or a portable hardness tester in accordance with ASTM A833.
9.5.3
A minimum of three hardness indentations shall be made on the parent
metal of each fitting, with the test locations spaced evenly across the
piece being tested. (For fittings 2-inch and smaller, only two
indentations are required.) For welded fittings, an additional three
hardness indentations shall be made evenly spaced, along the weld.
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Carbon Steel and Low Alloy Butt Welding Pipe Fittings
Where accessible, the weld metal hardness should be measured on
the I.D. surface of the fittings.
9.6
9.5.3.1
If any single indentation exceeds the allowable hardness
limit, two additional hardness indentations shall be taken
within 25 mm of it, and the three hardness values shall be
averaged. If the average exceeds the allowable limit, the
fitting shall be rejected, and all the other fittings from the
same heat shall be 100% hardness tested, even if not
otherwise required in paragraph 9.5.1.
9.5.3.2
The difference between the highest and lowest hardness
readings in the parent metal of each fitting shall not
exceed 20 HBW. In addition, for welded fittings, the
difference between the highest and lowest hardness
readings in the weld metal shall not exceed 20 HBW. If
the difference exceeds 20 HBW for either the parent
metal or the weld metal hardness values, the fittings shall
be rejected, and all other fittings from the same heat shall
be 100% hardness tested, even if not otherwise required
in paragraph 9.5.1. For the purpose of determining the
spread of HBW readings, a set of three indentations at
the same location may be substituted for any single
reading and the average of the three used instead of the
single reading.
9.5.3.3
At the manufacturer's option, all fittings that have failed
the hardness test requirements in paragraphs 9.5.3.1
and/or 9.5.3.2 can be re-normalized and hardness tested
again. Fittings that pass the hardness test requirements
and the strength requirements after re-normalizing may
be accepted. Fittings that fail a second time shall be
permanently rejected.
9.5.3.4
The hardness acceptance criteria shall be as per section
6 of this specification.
Charpy Impact Testing
9.6.1
Charpy impact testing requirements for fittings in Grades WPHY-42
and higher strength are given in MSS SP-75. Grade ASTM A234
Grade WPB fittings do not require impact testing unless specified in the
Purchase Order.
9.6.2
Grades WPL6, WPL9, WPL3 and WPL8 materials shall be tested as
specified in ASTM A420 except that the required Charpy V-notch
impact values shall be 34/27 J (25/20 ft-lbs) for standard 10 mm by 10
mm specimens.
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Carbon Steel and Low Alloy Butt Welding Pipe Fittings
9.6.3
For welded fittings, testing shall be performed on the base metal, heataffected zone, and the weld metal. The weld metal and heat-affected
zone impact test specimens shall be transverse to the weld axis.
•
Grade WPL 3 materials shall be tested as specified in ASTM
A420.
•
Grade WPL 6 materials shall be tested as specified in ASTM
A420 except that the required Charpy V-notch impact values
shall be 34/27 J (25/20 ft-lbs) for standard 10 mm by 10 mm
specimens.
Notes:
In the notation of required Charpy Values such as 25/20, the first number is the average
energy of three specimens while the second number is the minimum for any one specimen.
The provisions in ASTM A350 Paragraph 7.2.4 for subsize specimens and test temperature
reduction are the same as in ASME B31.3 Paragraph 323.3. Requirements for subsize
specimens in ASTM A960 and ASTM A370 shall apply.
9.7
9.6.4
Impact test procedures and apparatus shall conform to the applicable
paragraphs of ASTM A370.
9.6.5
The test temperature and the minimum Charpy energy requirements
shall be specified in the Purchase Order if different from the
requirements in paragraph 9.6.1 and 9.6.2.
NDE for forgings and hot rolled bars
All NDE shall be conducted after final heat treatment.
If an unacceptable imperfection or rejectionable indication is found on any test
sample the entire lot shall be tested.
9.7.1
Magnetic Particle Testing – Ferromagnetic Materials
All accessible surfaces shall be magnetic-particle tested after final heat
treatment and final machining operations by a wet fluorescent method
in accordance with ASTM A508/A275. Surfaces shall be inspected in
two directions: axial and circumferential.
Acceptance criteria shall be in accordance with ASTM A788
Supplementary Requirement S18.
9.7.2
Liquid Penetrant Testing – Non-ferromagnetic Materials
All accessible surfaces shall be liquid-penetrant inspected after final
heat treatment and final machining operations in accordance with
procedures specified in ASTM E165.
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Carbon Steel and Low Alloy Butt Welding Pipe Fittings
Acceptance criteria shall be in accordance with ASTM A788
Supplementary Requirement S19.
9.7.3
Ultrasonic Testing
Ultrasonic Testing (UT) shall be conducted in accordance with the
following requirements:
Testing shall be conducted from the welding end before beveling, in an
intermediate-machined state, with welding and sealing ends machined
at right angles to the bore. However, intermediate-machined state UT
inspection is not required if the intended UT procedure can
demonstrate, and document, that adequate inspection reliability of the
welding end can be achieved without intermediate stage testing. The
whole volume of the forging shall be tested.
9.7.3.1
Straight-Beam Examination
Test forgings in accordance with ASTM A388/A788.
ASTM A788 supplementary requirement S20 Level DA
applies, except that the flat bottom hole for test sections
up to 300 mm will not exceed 4 mm diameter, and the flat
bottom hole for sections 300 mm to 450 mm will not
exceed 6.5 mm diameter.
Acceptance Criteria:
9.7.3.2
•
A forging containing one or more indications equal
in amplitude to that of the applicable reference
hole, when properly corrected for distance, is
subject to rejection.
•
Multiple indications with an amplitude exceeding
50% of the indication from the calibration hole,
accompanied by a loss of back reflection
exceeding 50%, shall also be cause for rejection.
Angle-Beam Examination
Test forgings in accordance with ASTM A388/A508.
Search areas will consist of:
•
100% of the volume of the bore to a radial depth
not less than the wall thickness of the matching
pipe; and
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Carbon Steel and Low Alloy Butt Welding Pipe Fittings
•
100% of the volume of the cone, or the volume of
material contained within 50 mm of the welding
end, whichever is less.
Acceptance Criteria:
•
10
11
Recordable indications per ASTM A388 will be
cause for rejection.
Additional Requirements for Hydrogen Service
10.1
Fittings designated for hydrogen service, or services blended with
hydrogen, shall comply with specification and qualification
requirements outlined in ASME B31.12 as a minimum.
10.2
Grades containing Nickel additions above 0.50 shall not be used for
hydrogen service.
10.3
The phosphorus content for carbon steel and low temperature carbon
steel fittings shall not exceed 0.015%.
Positive Material Identification (PMI)
PMI shall be conducted randomly on finished Low Alloy Steel (Cr-Mo and Nialloy steel) fittings on each lot before dispatch. A minimum of 10% of fittings in
each heat must be tested. SAES-A-206 procedures shall be followed, as
applicable, for conducting PMI. Saudi Aramco representative may select the
fittings for testing. PMI shall include the weld metal of welded-type fittings.
12
Product Marking, Coating, Packing, and Documentation
12.1
Fittings per ASTM A234 and A420 shall be marked in accordance with
ASME B16.9, paragraph 4.
12.2
Fittings per MSS SP-75 shall be marked per MSS SP-75, paragraph
17.
In addition, the carbon equivalent shall also be marked on the O.D. of
the fitting.
12.3
Fittings manufactured for sour service shall be marked with “S”.
12.4
After inspection by Saudi Aramco's Inspection Representative, unless
otherwise specified in the Purchase Order, fittings shall be supplied
with a protective coating that does not hide markings or surface
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Carbon Steel and Low Alloy Butt Welding Pipe Fittings
defects. This temporary coating, combined with appropriate packing,
must protect against corrosion during ocean shipment. The coating
shall be hard and dry. It can be either a clear coating or a thin opaque
coating. Except for clear coatings, the maximum dry film thickness
shall be 76 micron. The fitting's normal stamped markings must be
readable.
12.5
All fittings must be protected from mechanical damage. Welding ends
must be protected with suitable wood, plastic, rubber or metal covers.
Fittings must be packaged in steel-banded wooden crates or secured
to skids.
Note:
If fittings up through 6-inch size are securely packaged in the wooden crates so that they
cannot shift during shipment and damage the welding bevels, the separate covers are not
required.
12.6
Documentation shall be in accordance with EN10204 “type 3.1”. The
results of all tests required in this specification shall be reported. The
reporting documentation shall be in the English language and three
copies shall be provided.
Document History
27 December 2021
Major revision:
1) Title change to include low allow fittings.
2) Add detailed clarifications to forged fittings requirements.
3) Add additional requirements for hydrogen service.
6 November 2019
Editorial: Extended Next Revision date out 2 years.
1 January 2018
Editorial revision to modify paragraphs 5.4 and 8.1.
31 December 2016
Major revision. Key updates:
1) Optimized paragraph 6.1 to eliminate forging from the fitting manufacturing
process,
2) Aligned hardness with latest industry practice (from BHN to HBW),
3) Added hardness reading limit for high strength fittings per MSS SP-75 as
235 HBW,
4) Aligned Supplementary Requirements of High Strength fittings with latest
industry MSS SP-75 edition,
5) Added restrictions on cold sizing after heat treatment to avoid excessive
cold working,
6) Added requirement for NDE to be conducted after completion of
manufacturing process,
7) Added requirement for the progressive examination if sample failed the body
DPT/MPT,
8) Incorporated the on-line and committee comments, added key references,
updated titles of some references, clarified requirements, and fixed all typos.
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