1. GENERAL
This specification defines minimum
quality and technical standards governing design, supply and manufacturing of
butt-welded pipeline fittings used with offshore pipelines. This specification is to be used in conjunction
with the following documents:
·
Basis of Design 84506-60-00-2L-060
·
General Specification
84506-60-00-2L-000 - Definitions and Specification Directory
·
General Specification
84506-60-00-2L-010 - Quality Assurance / Quality Control
·
ASME Code, Boiler and Pressure Vessel
Code, Section IX
·
ASTM A694 Standard Specification for
Forgings, Carbon and Alloy Steel, for Pipe
Flanges,
Fittings, Valves, and Parts for High-Pressure Transmission Service
·
ANSI B16.9-86 Factory-Made Wrought
Steel Buttwelding Fittings.
·
API 1104 Standard for Welding Pipelines
and Related Facilities.
·
MSS-SP-75 Specification for High Test
Wrought Butt Welding Fittings.
·
DNV OS–F101: Submarine
Pipeline Systems 2000.
2. FITTING REQUIREMENTS
CONTRACTOR shall supply butt-welded fittings that meet the
requirements specified in the Purchase Order, CONTRACT Documents or Project
Drawings, including quantity, type, ANSI class and any additional COMPANY
requirements. Butt-welded fittings,
including elbows, reducers and tees shall conform to MSS-SP-75 and the
additional requirements specified herein.
Fittings shall be compatible with the adjoining flange and
linepipe materials and will be in accordance with the following:
ANSI B16.9 butt welded fittings NPS2” to NPS14”
MSS-SP-75 for butt welded fittings NP 16” and larger
2.1 Supplementary
Requirements to MSS SP-75 – Export Pipeline System
The following MSS SP-75 supplementary requirements apply for
fittings made to this order.
·
SR1
·
SR2
·
SR7 and SR8 - The minimum average
Charpy impact value from each of 3 sets tested in accordance with Section 11 of
MSS-SP-75 shall be compatible with the grade of linepipe material to which they
will be used. Charpy V-notch values shall be in accordance with the minimum
mean values and single specimen values given in Table 6-3 of Section 6 of DNV
OS–F101. Test specimens shall be full size and the test temperature shall be
-10oC for Export Pipeline fittings.
·
SR9
·
SR10
·
SR11
·
SR13
·
SR14
2.2 Supplementary
Requirements to MSS SP-75 – Infield System
Charpy
V-notch impact tests on all NPS fittings shall be in accordance with the
requirements of Section 11 of MSS SP-75 with the following exceptions:
Test
specimens shall be full size and the test temperature shall be -39oC
for Infield Flowline fittings.
The
Charpy values for all NPS fittings shall be compatible with the grade of
linepipe material to which they will be used. Charpy V-notch values shall be in
accordance with the minimum mean values and single specimen values given in
Table 6-3 of Section 6 of DNV OS–F101.
If
the specimens fail to meet these requirements, the manufacturer shall take
remedial action acceptable to the COMPANY. Further test failure shall be basis
for rejection.
3. STEEL MANUFACTURING REQUIREMENTS
CEV = C + Mn + Cr + Mo + V
+ Cu + Ni
6
5 15
Material shall conform to the chemical analysis requirements
of DnV OS-F101. Chemical composition shall be controlled within more stringent
limits than the maximum values given in DnV OS-F101. CONTRACTOR shall submit the target value and
proposed range of each chemical element to COMPANY for approval. Agreed target values and ranges shall be
given in the approved manufacturing procedures
Welding
procedures and welding operators shall be qualified in accordance with DnV
OS-F101. Internal weld reinforcement
shall be ground flush prior to hot forming welded elbows over a mandrel.
Each chemical analysis taken and reported shall include the
percentage of each element specified or restricted by this specification. All
chemical compositions shall be subject to COMPANY approval.
4. HARDNESS REQUIREMENTS
CONTRACTOR shall certify that all finished components do not
exceed 270 HV10 in the base metal and 270 HV10 in the weld metal/heat affected
zone.
5. BEVELS
Welding ends shall be beveled for welding in accordance with
sub-section 13.3 of MSS SP-75 and API 1104 unless otherwise stipulated on
Request for Quotation or Purchase Order.
The root face shall not be brought into tolerance by filing
or grinding.
The surface of the bevel shall be smooth and free from tool
marks as to permit proper inspection for laminations. In removing any burr,
care shall be taken to avoid excessive removal of metal and the formation of an
inside bevel. Excessive removal of metal shall be cause for re-beveling.
All bevelled ends shall be inspected by a Company approved
non-destructive testing method.
The welding ends shall be machine parallel and square to the
pipe axis and shall have all burrs removed from both the inside and the outside
edges.
6. HEAT TREATMENT
Fittings shall be furnished in the normalized, normalized and
tempered, or quenched and tempered condition after all forming operations are
completed. Temperature ranges specified
in COMPANY-approved heat treating procedure(s) shall be measured during all
heat treatment. Thermocouples shall be
attached to representative flange parts in the batch to confirm actual metal
temperature.
7. NON-DESTRUCTIVE TESTING
Non-destructive testing techniques and procedures, including
radiography, Magnetic Particle Inspection (MPI) and Ultrasonic Testing (UT) are
to be employed by CONTRACTOR shall be submitted in writing to COMPANY for
approval prior to starting production.
7.1 Technicians performing nondestructive
inspection on this order shall be qualified to the requirements of SNT-TC-1A,
Level II or equivalent.
7.2 Butt-welded fittings shall be one hundred
percent (100%) visually inspected for surface defects and dimensional
tolerances.
7.3 Radiographic inspection of all butt welds
shall be performed in accordance with, and meet the requirements of, MSS-SP-75.
7.4 Finished fabricated butt-welded fittings
shall be subject to 100 percent MPI of all accessible surfaces.
8. REPAIR OF DEFECTS
8.1 Weld
repairs to base metal are not permitted.
8.2 Surface
defects such as slivers, notches, gouges, etc. shall be repaired by grinding or
machining. The machined or ground area
shall be dressed to a smooth transition with surrounding surfaces. If the section/wall thickness is reduced
below the minimum specified, the fitting shall be rejected. No repairs shall be made without COMPANY
approval.
9. DIMENSIONAL TOLERANCES
Tolerances on fabricated and forged butt-welded fittings
shall meet the requirements of MSS-SP-75, ANSI B16.9 and the Project Drawings.
10. MARKINGS AND COATINGS
Butt-welded
fittings shall be identified in accordance with ASTM A694, with the following
data stamped on the flange periphery by low stress, round-nosed or interrupted
dot die stamps:
·
ADGF Project
·
Manufacturer's Name
·
Fitting Identification Number /
Purchase Order Number
·
Heat Number
·
Material grade
·
Pressure Rating
·
Diameter and Wall Thickness
10.1 Fabricated and forged butt-welding fittings
shall be abrasive blasted to remove loose scale and foreign material after
performing all required heat treatment, and prior to inspection.
10.2 Fabricated and forged butt-welding fittings
shall be externally coated with a COMPANY-approved two-component epoxy paint
system suitable for the intended environment.
10.3 Beveled ends shall be protected against
physical damage during transit. Ends
shall be coated with a weldable primer such as Deoxaluminite, or
COMPANY-approved equal, that can easily be removed with solvent and that will
prevent rusting of weld bevel faces for a period of at least twelve (12)
months, under exposed field conditions.
11. INSPECTION AND REJECTION
11.1 CONTRACTOR
shall furnish COMPANY reasonable facilities and space, without charge, and
shall provide COMPANY with free access to all parts of all plants concerned
with fabrication or forging of butt-welding fittings, for COMPANY inspection and
testing as deemed necessary.
11.2 COMPANY
may inspect butt-welding fittings for compliance with this specification, at
all stages of the manufacturing and delivery process. This inspection shall in no way relieve
CONTRACTOR of its responsibilities for compliance with the specifications.
11.3 COMPANY
inspectors shall operate independently of CONTRACTOR inspectors.
11.4 Butt-welding
fittings shall be rotated at the final inspection bench, where the minimum
illumination level on all surfaces shall be 350 lux. All components shall be checked for
mechanical damage, correct weld bevel preparation and marking, and end
protection.
11.5 All
materials shall be COMPANY approved prior to procurement.
11.6 All
records shall be fully identified with the specific materials they represent,
and shall be available for COMPANY examination at the time and place of
inspection, whether at the point of manufacture or other CONTRACTOR locations.
12. SHIPMENT
CONTRACTOR shall submit, for COMPANY approval, drawings of
proposed butt-welded fittings stacking and shipment procedures.
Timber blanks or metal end bevel protectors shall be used to
protect end bevels.
Fittings shall be lifted and stacked only by methods that
prevent damage to the fittings and their end bevels.
12.1 Butt-welding
fittings shall be located so as to reduce the possibility of critical stresses
and fatigue cracks due to cold working in transit.
12.2 Butt-welding
fittings shall not rest on the surface of any longitudinal pipe welds. Stresses shall be limited so that no
additional out-of-roundness of butt-welded fittings should occur during
shipment.
13. DOCUMENT SUBMITTALS
CONTRACTOR shall submit to COMPANY for approval, 30 days
prior to scheduled manufacturing start date, the following:
·
QC Procedures
·
Materials certification
·
Work Procedures
·
Steel Making / Casting Methods
·
Chemical Composition
·
Shop Drawings
·
Packing and Handling Procedures
·
Inspection and Test Plans
CONTRACTOR shall submit to COMPANY for approval the
following:
·
Equipment Calibration Certificates
·
Inspection and test records
CONTRACTOR shall submit a databook to COMPANY for approval
containing the following documents as a minimum.
·
Certified as Fabricated Drawings
·
Mill Certificates containing
- Ladle Analysis (each heat)
- Product Check Analysis (each heat)
- Certified NDE Reports
- Certified Mechanical Test Reports
All certificates shall be in the English language and use
metric units of measure. CONTRACTOR and
COMPANY shall visibly sign certificates.
All data shall be provided in hard copy and electronic
format.