Materials System Specification
Materials System Specification
Materials System Specification
I Scope............................................................. 2
II Conflicts and Deviations................................. 2
III References..................................................... 2
IV Modifications to API SPEC 5LD..................... 4
I Scope
This Specification covers clad and lined pipe (seamless and welded), manufactured in
accordance with API SPEC 5LD (4th Edition, 2015).
Commentary:
Weld overlay pipe shall be limited to line pipes intended for spool fabrication, offshore
platform topside piping, risers, etc. Metallurgically-bonded clad pipe shall be used for the
construction of full length pipes. Mechanically-bond lined pipe is prohibited for sub-sea
applications as per SAES-L-136.
A. Any conflicts between this specification and other applicable Saudi Aramco
Materials System Specifications (SAMSSs), Engineering Standards (SAESs), or
industry standards, codes, and forms shall be resolved in writing by the
Company or Purchaser Representative through the Manager, Consulting
Services Department of Saudi Aramco, Dhahran.
B. Direct all requests to deviate from this specification in writing to the Company
or Purchaser Representative, who shall follow internal company procedure
SAEP-302 and forward such requests to the Manager, Consulting Services
Department of Saudi Aramco, Dhahran.
III References
The manufacture and purchase of material covered by this specification shall comply with
the latest edition (as per the project proposal date) of the references listed below, as noted.
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Document Responsibility: Materials Engineering Standards Committee 01-SAMSS-048
Issue Date: 6 October 2015
Next Planned Update: 6 October 2018 CRA Clad or Lined Steel Pipe
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Document Responsibility: Materials Engineering Standards Committee 01-SAMSS-048
Issue Date: 6 October 2015
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and Strip
ASTM B443 Standard Specification for Nickel-Chromium-
Molybdenum-Columbium Alloy (UNS N06625)
and Nickel-Chromium-Molybdenum-Silicon Alloy
(UNS N06219) Plate, Sheet, and Strip
ASTM B499 Standard Test Method for Measurement of Coating
Thicknesses by the Magnetic Method:
Nonmagnetic Coatings on Magnetic Basis Metals
ASTM E562 Standard Test Method for Determining Volume
Fraction by Systematic Manual Point Count
ASTM G28 Standard Test Methods for Detecting Susceptibility
to Intergranular Corrosion in Wrought, Nickel-
Rich, Chromium-Bearing Alloys
ASTM G48 Standard Test Methods for Pitting and Crevice
Corrosion Resistance of Stainless Steels and
Related Alloys by Use of Ferric Chloride Solution
The following paragraph numbers refer to API SPEC 5LD which is the basis for this
specification. The text in each paragraph below is an addition or modification to
API SPEC 5LD, as noted. Paragraph numbers not appearing in API SPEC 5LD are new
paragraphs to be inserted in numerical order.
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Document Responsibility: Materials Engineering Standards Committee 01-SAMSS-048
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1 Scope [modification]
The carbon steel backing or base material shall meet the requirements of
01-SAMSS-035 in addition to the requirements of API SPEC 5L PSL2,
except as modified herein. The carbon steel backing pipes shall be procured
only from the sources approved by Saudi Aramco.
Commentary:
Contact Saudi Aramco buyer for a list of Saudi Aramco approved pipe mills.
This class is for gas, two-phase flow, and liquid lines such as NGL, whose
vapor pressure exceeds 100 psia.
3.2 Acronyms
CRA Corrosion Resistant Alloy
CSD Consulting Services Department
ESW Electroslag Welding
HFW High Frequency Welded
MPS Manufacturing Procedure Specification
MPQT Manufacturing Procedure Qualification Test
PREN Pitting Resistance Equivalent Number
SAW Submerged Arc Welding
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Document Responsibility: Materials Engineering Standards Committee 01-SAMSS-048
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5.1 General
The minimum thickness of the CRA layer for lined pipes and clad pipes
shall be 2.5 mm unless otherwise agreed.
The seamless and welded backing carbon steel pipe (backing carbon steel in
case of clad plates) shall meet the requirements of API SPEC 5L PSL2 and
Saudi Aramco specification 01-SAMSS-035. The mechanical expansion
requirement stated in paragraph 8.9.2 of 01-SAMSS-035 does not apply).
HFW and Spiral-SAW pipes shall not be used as backing steel for
manufacture of clad pipes.
Commentary:
If the size required is beyond the available diameter range of L-SAW pipes,
Spiral-SAW can be used for manufacturing of clad pipes by weld overlay, if
approved by the Chairman of the Materials Engineering Standards Committee.
The backing steel pipe shall be seamless or L-SAW and shall meet the
requirements of API SPEC 5L PSL2 and Saudi Aramco specification
01-SAMSS-035. Spiral-SAW or HFW pipes shall not be used as backing
steel for lined pipes.
Commentary:
If the pipes are ordered for wet sour service, the heat treatment condition of
the CRA material shall be in accordance with NACE MR0175/ISO 15156.
5.5.1 Weld overlay, including overlay on pipe ends of lined pipe, shall be carried
out using GTAW process and a minimum of two layers shall be applied.
Exception to this requirement for overlay on pipe ends of lined pipe can be
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Document Responsibility: Materials Engineering Standards Committee 01-SAMSS-048
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Single layer automatic PAW, PTA or ESW can be used for overlay on long
seam for pipes made from clad plates. Other welding processes can be used if
approved by the Chairman of the Materials Engineering Standards Committee.
5.5.2 All weld repairs on CRA overlay shall be carried out using automatic
GTAW or PAW process. Repairs by manual welding and using other
processes can be done if approved by the Chairman of the Materials
Engineering Standards Committee.
5.5.3 Welding heads for GTAW and PAW used for overlay must be equipped with
automatic voltage control facility.
5.5.4 If multiple heads are used (tandem welding) for depositing multiple layers
by weld overlay, any decrease in distance between the heads shall be
considered as an essential variable.
5.5.5 Back purging, if required, shall be done with welding grade inert gas during
the long seam welding and it shall be ensured that the weld is free from high
temperature oxides.
5.5.6 All welding procedures, including procedures for repair, must be reviewed
and approved by the Chairman of the Materials Engineering Standards
Committee.
5.5.7 The corrosion properties of the CRA weld consumables shall be compatible
with the corrosion property requirements of the clad material.
5.5.8 All welding consumables used, including repairs, must be classified as per
American Welding Society classification requirement. Alternative
classification is acceptable, if approved by CSD.
5.5.9 Selection of welding filler wire for weld overlays for any of the welding
processes that use bare wire shall be as recommended in Table 1 below.
Table 1(3)
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Document Responsibility: Materials Engineering Standards Committee 01-SAMSS-048
Issue Date: 6 October 2015
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(1) UNS N08367 and N08926 are acceptable substitutes to UNS S31254. If UNS
N08367 or N08926 are offered in lieu of UNS S31254, all the requirements of
UNS S31254 stated in this specification shall apply.
(2) This table does not apply to single layer weld overlay made on the long seam of
clad pipes made form clad plates.
(3) Filler wire used for weld overlay of pipe ends of lined pipe shall match with the wire
to be used for girth welding in the site. Information pertaining to consumable
selection for girth welding may be obtained from the Chairman of the Materials
Engineering Standards Committee.
Commentary:
5.5.10 The brand name for nickel based and duplex/super duplex stainless steel
filler wire shall be considered as an essential variable.
5.5.11 The tab ends (run-in and run-off plates) shall be made from cladded plates of
same wall thickness and CRA material specification. This requirement can
be exempted depending on the welding sequence, if approved by Chairman
of the Materials Engineering Standards Committee.
5.5.12 Explosion bonded plates can used for manufacture of clad pipes only if
approved by the Chairman of the Materials Engineering Standards Committee.
5.5.13 Clad plates shall be procured from approved steel mills. The list of approved
mills can be obtained from Saudi Aramco Purchasing Representative. The pipe
manufacturer shall still be responsible about the quality of the procured clad
plates. Procurement of plates from unlisted vendors shall be approved by
Chairman of the Materials Engineering Standards Committee.
5.6.1 The internal surface of the carbon steel backing pipe shall be blast cleaned to
a surface finish of SSPC SP10 (Sa2.0) along the complete length of the pipe
prior to fabrication.
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Document Responsibility: Materials Engineering Standards Committee 01-SAMSS-048
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5.6.2 The humidity of air in the annular space between the carbon steel backing pipe
and the CRA liner during assembly shall be less than 80% and the carbon steel
and CRA surfaces shall be maintained at least 5°C above the dewpoint
temperature. Temperature and humidity shall be continuously controlled.
5.6.3 Expansion of the liner after assembly is mandatory. The expansion of the
carbon steel backing pipe shall not exceed 1.5%.
5.6.4 The pipe ends of lined pipes must be weld overlayed for a minimum length
of 50 mm.
Commentary:
The quotation shall include the additional cost to be charged for every 5 mm
increase in the overlay length. This would allow increasing the overlay length
during any stage of manufacturing depending on the pipe size and the
recommendation of the laying contractor.
5.6.5 The requirements stated in 5.5 and 6.1 shall also apply for overlaying the
pipe ends of lined pipes.
For PMI, the chemical composition of the weld deposit shall be checked on
the final finished surface of the production weld overlay.
The weld deposit chemistry shall be within the range specified for the UNS
number of the CRA (ASTM B424 for UNS N08825 and ASTM B443 for
N06625). In case of alloy N06625, the iron content shall not exceed 10%.
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Document Responsibility: Materials Engineering Standards Committee 01-SAMSS-048
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Table 2
If the pipes are ordered for class IV service, the minimum average Charpy
impact energy value for backing steel pipe shall be as specified by the Buyer
in the relevant requisitions, quotation requests, and purchase orders as per
SAES-L-131. The CVN test shall include weld, HAZ and base metal.
Commentary Note:
If the pipes are ordered for class IV service and if the diameter of the welded
backing steel pipe is greater than or equal to 20”, DWTT shall be carried as
per 01-SAMSS-035 and API SPEC 5L Annex G. Sub-size specimens for
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Document Responsibility: Materials Engineering Standards Committee 01-SAMSS-048
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DWTT of the clad plates shall be prepared by milling the carbon steel
equally from the CRA boundary and the opposite side.
Ferrite content for pipes lined or clad with UNS S32205 and
UNS S32750 shall be determined in accordance with paragraph 8.1 of
API SPEC 5LC. The frequency of testing shall be identical to the frequency
of testing for corrosion tests.
The hardness indents nearest to the fusion line shall test the high temperature
HAZ and shall be within 0.2 mm of the fusion line. The hardness of the
backing steel shall not exceed 248 HV10. Hardness testing of the backing
steel material is required even if the pipes are not ordered for sour service
(see paragraph 9.17 of 01-SAMSS-035).
Commentary:
The hardness measurement nearest the fusion line applies only to the long
seam weld fusion line of the backing carbon steel pipe and does not apply to
the fusion line between the CRA overlay and the backing carbon steel pipe.
If the pipes are ordered for sour service, the hardness of the CRA layer shall
be in compliance with NACE MR0175/ISO 15156 and API SPEC 5LD.
8 Special Tests
8.2.1 All austenitic stainless steel grades (weld metal and base metal) except those
specified in Table 3 shall be subjected to intergranular corrosion test as per
ASTM A262 Practice E. Requirement for sensitization of samples shall be
as specified in ASTM A262 except that sensitization heat treatment is not
required for grades having more that 3% Mo.
8.2.2 Intergranular Corrosion test specified in paragraph 8.2.1 above is not required
for heats having less than 0.020% carbon as shown in product analysis.
8.2.3 The following grades shall be subjected to the corrosion testing as specified
in Table 3 below.
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Table 3
Notes:
a. The surfaces of the specimens shall be in the “as delivered” condition unless stated otherwise in the
applicable standard.
b. Cut edges shall be prepared according to ASTM G48, and the whole specimen shall be pickled if the
pipes are to be delivered after pickling.
c. Weight loss requirement does not apply to weld overlays.
d. Rapid screening test (ASTM A923 Test Method A) shall not be used as an acceptance test.
e. UNS N08367 and N08926 are acceptable substitutes to UNS S31254. If UNS N08367 or N08926 is
offered in lieu of UNS S31254, all the requirements of UNS S31254 stated in this specification shall
apply.
f. In case of pipes made from clad plates, the corrosion test sample shall include the clad base material
with weld at the center and the CRA weld reinforcement shall be ground flush. In case of lined pipe,
the CRA liner as well as the weld overlay shall be tested.
8.2.4 The frequency of testing, specimen sampling and specimen preparation shall
be in accordance with paragraph 8.2 of API SPEC 5LD and the requirements
stated in 8.2 above.
8.2.5 Corrosion specimens for clad pipes made by weld overlay (including overlay
for pipe ends of lined pipe) shall be prepared by removing the backing
carbon steel by milling or by other means. The thickness of the specimen
shall not be less than 2.0 mm. Specimen thickness down to 1.5 mm can be
accepted for small diameter pipes if approved by the Chairman of the
Materials Engineering Standards Committee.
8.3 Testing for CRA Cladding Bond Strength and CRA Liner Tightness
[modification]
Clad Steel Pipe – Bond strength test shall be carried out by conducting bend
tests in accordance with ASTM A264 or A265, as applicable. Additionally,
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Document Responsibility: Materials Engineering Standards Committee 01-SAMSS-048
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Next Planned Update: 6 October 2018 CRA Clad or Lined Steel Pipe
Lined Steel Pipe – Residual compressive stress test shall be carried out in
accordance with API SPEC 5LD as part of the MPQT only. The acceptance
criteria shall be as agreed upon. In addition, gripping/push out test shall be
carried out as part of the production test. The length of the sample shall be
280 mm and the cut back length for the backing carbon steel pipe shall be
30 mm. The acceptance criteria shall be 15N minimum per mm of diameter.
9.6 The chloride content of the water used for hydrostatic testing shall not
exceed 50 ppm. The pipes should be dried and cleaned immediately after
the Hydrotest [addition].
Table 4
Notes: 1. 100% of the pipes shall be inspected for pipe end dimensions.
2. The inside pipe diameter can be fixed by the pipe manufacturer at the beginning of
production and tolerances can be based on the constant actual ID fixed by the
manufacturer at the start of pipe production. The dimensions must however be within the
range allowed by API SPEC 5LD.
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Document Responsibility: Materials Engineering Standards Committee 01-SAMSS-048
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10.9 For welded pipes, the inside and outside weld reinforcement shall be
removed by grinding for a distance of at least 6 inches from each pipe end
such that it does not extend above the pipe surface by more than 0.5 mm
[addition].
11 Nondestructive Inspection
11.1.1 The weld seam of welded clad pipe shall be inspected full length (100%) by
radiological methods in accordance with API SPEC 5L, Section E.4 or by
automatic ultrasonic testing procedures (inspection of pipe ends can be carried
out by radiographic testing or manual ultrasonic testing). An automatic
ultrasonic inspection shall be performed for disbondment of the cladding
along the zone 50 mm on each side of the weld seam. The UT machine shall
be equipped with seam tracking and permanent recording facility. Pipe ends
can be tested by manual ultrasonic testing.
11.1.4 Clad plates shall be visually inspected in accordance with ASME SEC V
Article 9. Defects such as pits, scratches, etc., that are deeper than 0.5 mm
are not acceptable. The surface roughness of CRA, as defined by center line
average method, shall not exceed 12.5 µm.
11.4.1 CRA wall thickness on the clad plates shall be checked at least nine points
using magnetic field induction method as per ASTM B499. Locations of
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Document Responsibility: Materials Engineering Standards Committee 01-SAMSS-048
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11.4.2 In case of weld overlayed pipes, thickness of the overlay shall be measured
by taking thickness measurements before and after weld overlay, or after
machining as applicable, by using ultrasonic examination. Readings shall be
taken at least four locations.
Level 1 personnel may set up the equipment, perform tests, and report the
results. Supervision of Level 1 personnel and interpretation of results shall be
done by Level 2 employees. The primary Level 3 employee such as company
employee, outside consultant, or third party inspector shall be certified in
accordance with ASNT CP-189 or ISO 9712 or ASNT SNT-TC-1A or by an
independent certifying body acceptable to Saudi Aramco. Working practice
for qualification shall be submitted to Saudi Aramco for approval.
Positive Material Identification (PMI) shall be carried on the CRA layer for
one out of every 50 pipes in case of lined pipes (including weld overlay) and
pipes made from clad plates. Any change in heat number of the strip or wire
used for CRA overlay on the clad pipes made from clad plates, shall require
PMI. In case of clad pipes made by weld overlay, PMI shall be conducted on
each pipe, provided the diameter of pipe allows for accessibility. Acceptance
criteria shall be as per the chemistry requirement for the CRA alloy with a
tolerance of 10% (in case of weld overlays, the range of elements specified in
ASME SEC II Part C or AWS shall apply).
Weld overlay surface of the clad pipes, including weld overlay at the pipe
ends of lined pipes and accessible length of overlay on the long seam of
pipes made from clad plates, shall be tested by dye penetrant test.
The acceptance criteria shall be in accordance with API SPEC 6A PSL3.
Weld repairs on the completed pipe on CRA layer is permitted only for clad
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Document Responsibility: Materials Engineering Standards Committee 01-SAMSS-048
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It is acceptable to carry out limited weld repairs on the long seam of CRA
pipe per API 5LC before assembly.
12.4.2 Pipe ends shall be protected by caps in order to prevent build-up of moisture
in the pipe. Carbon steel shall not be used for pipe end protection.
[modification]
13 Marking
The area of the pipe to be marked shall be clean and dry. The markings shall
be paint stenciled using a medium and protective varnish that will provide a
legible marking for at least one year of outside storage. The varnish coating
shall be hard drying and the dry film thickness should not exceed
50 micrometers. The size of the lettering shall be commensurate with the
diameter of the pipe, but in no case less than 0.75 inch (0.59 inch for
diameter 6 inches and smaller) and in height for API markings and 13 mm in
height for shipping markings. All marking shall be carried out on the
outside surface of the pipe. The pipe number shall be hard stamped on the
square edge using low stress die-stamping.
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Document Responsibility: Materials Engineering Standards Committee 01-SAMSS-048
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13.4 All pipes shall be monogrammed as API SPEC 5LD in accordance with
Annex A of API SPEC 5LD.
14 Documentation
14.3 Test certificate shall state that the radiation levels from the pipes are less
than 100 beckerels/gram or equivalent. The certification can be based on
measurements reported by the steel mill supplying the raw material.
15.1 After surface treatment of the CRA, it shall be ensured that the CRA layer
does not come in contact with carbon steel during handling (crane hooks,
etc.) and transportation.
15.2 Pipes shall be stored on wooden bearing strips. If pipes are stored on rails or
steel beams, rubber sheets shall be used to prevent direct contact between the
pipes and the rails/beams. Storage and handling practice must ensure that
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Document Responsibility: Materials Engineering Standards Committee 01-SAMSS-048
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15.4 API SPEC 5L1 and API SPEC 5LW shall be followed for transportation of
pipes by rail road and marine transportation respectively.
Revision Summary
6 October 2015 Major revision to align with API 5LD (4th Edition, 2015) and incorporate applicable
benchmark study results.
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Document Responsibility: Materials Engineering Standards Committee 01-SAMSS-048
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Manufacturing procedure specification (MPS), in accordance with this annex and modifications
stated below, shall be submitted to the Chairman of the Materials Engineering Standards
Committee, Saudi Aramco, for review and approval.
B.1 The following information pertaining to the clad pipe shall also be included in the
MPS:
Slab reheating temperature and initial rolling practice of CRA and backing
material prior to sandwich assembly.
If nickel plating is done in between the backing steel and CRA, plating method,
plating thickness, etc. shall be included.
Method used to assemble the sandwich or one-sided-open package, as
applicable, prior to reheating and rolling.
Package (sandwich or one-side-open) reheating temperature, start and stop
rolling temperatures, means of temperature and thickness control, start and stop
temperature for accelerated cooling (if applicable) and inspection.
Final plate heat treatment, e.g., Q&T (if applicable).
Method used to cut and separate the metallurgically roll bonded plates after
rolling (separation of the sandwich between the CRA layers).
Details regarding any CRA clad welding to pipe ends.
B.2 The following information pertaining to the lined pipe, as applicable, shall also be
included in the MPS:
1. Details of fabrication of backing pipe and liner.
2. Quality control checks for the lining process.
3. Details of data to be recorded (e.g., expansion pressure/force, strain,
deformation).
4. Procedure for cut back prior to seal welding or cladding to attach liner pipe to
carrier pipe.
5. Details regarding any CRA clad/welding to pipe ends.
6. Procedure for conducting coating test (D.2 o)
7. Procedure for conducting bend trials (D.2 p)
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Document Responsibility: Materials Engineering Standards Committee 01-SAMSS-048
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Document Responsibility: Materials Engineering Standards Committee 01-SAMSS-048
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MPQT shall be established from the work order material from first day production. MPQT must
include all the applicable mechanical and chemical tests. Saudi Aramco inspection representative
shall have the right to select the pipe from first day production for establishing MPQT. The test
results shall be submitted to Saudi Aramco inspection representative. The manufacturer may
continue with production, without waiting for MPQT results, at his own risk. Tests done for
qualification of MPQT can be considered as part of production test.
Commentary:
1. It is noted that the length of overlay at pipe ends of lined pipe is limited to 50 mm.
Hence, the Saudi Aramco Inspection Representative must give adequate prior notice
to the pipe mill so that the liner length can be reduced in order to increase the overlay
length so as to accommodate the entire required destructive test.
The following tests shall also be conducted as part of MPQT for lined pipes only:
o) Coating simulation test shall be conducted by heating the pipe to 250°C for
15 minutes. The liner shall be visually inspected after the test and must be
free from any buckling.
p) If the pipes are ordered for offshore (submarine) service, bending simulation
test, simulating the S-legging lay barge conditions shall be carried out.
The liner shall be free from any wrinkles or buckling. The test procedure
shall be submitted to the Chairman of the Materials Engineering Standards
Committee, for approval, prior to testing.
Commentary:
Previous data within qualification range may be submitted to the Chairman of the
Materials Engineering Standards Committee for consideration so as to exempt this
test.
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