API 5L pipe is carbon steel pipe used for oil and gas transmissions, it includes the pipes manufactured in seamless and welded (ERW, SAW). Materials covers API 5L Grade B, X42, X46, X52, X56, X60, X65, X70, X80 PSL1 & PSL2 onshore, offshore and sour services. API 5L the implementation standard of steel pipe for pipeline transportation system and specification for line pipe.
Our Supply Range for API 5L Pipe
Grades: API 5L Grade B, X42, X52, X56, X60, X65, X70, X80
Product Specification Level: PSL1, PSL2, onshore and offshore sour services
Outer Diameter Range: 1/2" to 2", 3", 4", 6", 8", 10", 12", 16 inch, 18 inch, 20 inch, 24 inch up to 40 inch.
Thickness Schedule: SCH 10. SCH 20, SCH 40, SCH STD, SCH 80, SCH XS, to SCH 160
Manufacturing Types: Seamless (Hot Rolled and Cold Rolled), Welded ERW (Electric resistance welded), SAW (Submerged Arc Welded) in LSAW, DSAW, SSAW, HSAW
Ends Type: Beveled ends, Plain ends
Length Range: SRL (Single Random Length), DRL (Double Random Length), 20 FT (6 meter), 40FT (12 meter)or customized
Protection Caps in plastic or iron
Surface Treatment: Natural, Varnished, Black painting, FBE, 3PE (3LPE), 3PP, CWC (Concrete Weight Coated) CRA Clad or Lined
Here we will do a brief introduction of API 5L pipe and related standard specifications with below aspects:
Standard Scope
Manufacturing types
Different Grades (Covers B, X42, X46, X52, X60, X65, X70)
Delivery condition (R, N, Q, M means)
Product Specification Level (PSL1 and PSL2)
Material specifications (Chemical and Mechanical)
Test Mehtods
Tolerances on pipe diameters, wall thickness, out-of-roundness
Common defects
Line pipe history and milestones
Applications
API 5L Pipe Standard Scope
In API SPEC 5L 46th Edition, it is defined the scope as:"Requirements for the manufacture of two product specification level (PSL1 and PSL2) of seamless and welded steel pipes for use in pipeline transportation systems in the petroleum and natural gas industries. This standard is not applicable to cast pipe."
In a word, API 5L pipe is the carbon steel pipe applied to the oil and gas transmission system. Meanwhile other fluids like steam, water, slurry also could adopt the API 5L standard for the transmission purposes.
Different Manufacturing Types
API 5L specification covers the manufacturing types in welded and seamless.
Welded Type: ERW, SAW, DSAW, LSAW, SSAW, HSAW Pipe
For API 5L welded pipe common types as Follows:
ERW: Electric Resistance Welded, for pipe diameter normally under 24 inch.
DSAW/SAW: Double Submerged Arc Welding / Submerged Arc Welding, a substitute welding method than ERW for larger diameter pipes.
LSAW: Longitudinal SAW, for diameter up to 48 inch. Also called JCOE manufacturing process.
SSAW/HSAW: Spiral Subemerged Arc Welded / Helical SAW, pipe diameters up to 100 inch.
Check here for the differences between the ERW, LSAW, and SSAW pipe.
Seamless Type: Hot Rolled Seamess and Cold Rolled Seamless Pipe
Seamless manufacturing type usually for the small diameters pipe, normally diameter under 24 inch.
(For the pipe diameter is less than 150 mm or 6 inch, the seamless steel pipe is more applied than steel pipe in welded.)
There are also big diameters seamless pipe. By hot rolled manufacturing process we could get seamless pipe diameters at most 20 inch (508 mm). But if you need the seamless pipe more than 20", we can get it through hot expanding processes, maximum diameters to 40 inch 1016 mm.
API 5L Pipe Manufacturing Development
Besides Seamless and ERW, SAW manufacturing technologies, in the earliest years the API 5L steel pipe also could be made in furnace lap-welded (deleted in API 5L in 1962).
As the development of pipeline steel plate making technology, pipe forming and welding technology also has been much improved, so a lot of ERW pipe and SAW pipe used in the pipeline constructions. Specially for the big diameter steel pipe, SAW pipe gains a great advantage. With less raw material cost, simplified and uniform production procedures, welded steel pipe has taken the first place in oil and gas line pipe industries.
API 5L covers Grade B, X42, X46, X52, X56, X60, X65, X70, X80
API 5L steel line pipe adopts different steel grades, generally are Gr. B, X42, X46, X52, X56, X60, X65, X70, X80. Some manufacturers are capable of manufacturing steel grade up to X100 and X120. As the steel line pipe grades higher, more strictly control on the carbon equivalent control, and higher mechanical strength performances.
More over, for the same grade API 5L pipe, seamless and welded chemical elements content is different, which welded pipe is required more strictly and lower on Carbon and Sulfur.
By different delivery condition, there are also As-rolled, normalizing rolled, thermomechanical rolled, normalizing formed, normalized, normalized and tempered, quenched and tempered.
Delivery Conditions for Each API 5L Grade
To be continue:
For intermediate grades, API 5L pipe grade shall be in one of following description format:
a. The letter L followed by the specified minimum yield strength in Mpa. For example, L290 (X42) means the minimum yield strength is 290 Mpa. In case of PSL2 pipe, Suffix letter (R, N, Q or M) shall be added to describe the delivery condition;
b. The letter X followed by a two or three digital number equal to the minimum yield strength in 1000 psi rounded down to the nearest integer and, for PSL2 pipe, the letter describing the delivery condition (R, N, Q, or M) consist with the above formats.
Letter R: As rolled
Letter N: Normalizing rolled, Normalized formed, Normalized
Letter Q: Tempered and quenched
Letter M: Thermomechanical rolled or thermomechanical formed
Letter S: Sour Services, comes with PSL2 pipe with for NS, QS, MS, eg API 5L X52MS, API 5L X65QS.
Product Specification Level (PSL1 and PSL2 in API 5L)
What is PSL
PSL is the abbreviation of product specification level. The product specification level can be divided into PSL1 and PSL2, it also could be deemed as quality level.
PSL1 and PSL2 differences
Please click here for the differences between PSL1 and PSL2 pipes.
Requirement
PSL1 and PSL2 are not only different for testing requirements, but also for chemical composition and mechanical properties.
PSL1 is more strict than PSL2 in chemical composition, tensile properties, impact test, nondestructive testing and other indicators.
For more details please click here for Differences between API 5L PSL1 and PSL2.
Impact Test
PSL1 does not require impact test, and PSL2 need to do except X80.
Non-destructive Test
PSL1 does not require non-destructive test, where PSL2 required non-destructive test.
(NDT: Non-destructive inspection and testing. It is to use radiographic, ultrasonic or other methods (not to breaking the material) in API 5L standard, to reveal pipe defects, imperfections.)
API 5L Pipe Data Sheet Specification
API 5L Pipe Data Sheet specification including chemical composition and mechanical properties for PSL1 and PSL2 pipe.
Chemical Composition
Chemical composition for PSL1 line pipe with wall thickness ≤ 25.0 mm (0.984 inch)
API 5L Pipe Datasheet in PDF
API 5L PSL2 Pipe chemical properties:
Chemical Composition for API Sour Pipe
a. If C > 0.12%, CEIIW limits shall be applied; If C ≤ 0.12%, CEPCM shall be applied.
b. For each reduce of 0.01% for maximum C, an increase of 0.05% maximum Mn is permissible, up to a maximum of 0.20%.
c. Al ≤ 0.060%; N ≤ 0.012%; Al/N ≥ 2:1 (titanium-killed or titanium-treated steel not applicable); Cu ≤ 0.35% (Cu ≤ 0.10% if agreed); Ni ≤ 0.30%; Cr ≤ 0.30%; Mo ≤ 0.15%; B ≤ 0.0005%.
d. For seamless and welded pipes, Ca ≤ 0.006%; For welded pipe if Ca is added by intention, unless agreed, Ca/S ≥ 1.5 in case S > 0.0015%.
e. For SMLS pipe maximum limit for S could be increased to ≤ 0.008%, and in case welded if agreed to ≤ 0.006%. For higher S conent in welded pipe, lower Ca/S ratios maybe agreed.
f. Nb + V ≤ 0.06%, unless otherwise agreed.
g. Nb + V + Ti ≤ 0.15%.
h. In case seamless pipe, listed CEPCM value could be increased by 0.03.
i. Mo ≤ 0.35% in case agreed.
j. Cr ≤ 0.45% in case agreed.
k. Cr ≤ 0.45% and Ni ≤ 0.50% in case agreed.
Tensile and Yield strength
For intermediate grades, the difference between the specified minimum tensile strength and minimum yield strength for the pipe body shall be as given in the table for the next higher grade. The specified minimum tensile strength for the weld seam shall be the same value as was determined for the pipe body ung footnote a)
a. For intermediate grades, the difference between specified maximum yield strength and minimum YS shall be as given in the table for the next higher grade, and the difference between specified minimum tensile strength and the specified minimum TS shall be as given in the table for the next higher grade. For intermediate grades up to Grade L320 or X46, the tensile strength shall be ≤ 655 MPa (95 000 psi). For intermediate grades greater than Grade L320 or X46 and lower than Grade L555 or X80, the tensile strength shall be ≤ 760 MPa (110 200 psi).For intermediate grades higher than Grade L555 or X80, the maximum permissible tensile strength shall be obtained by interpolation. For SI units, the calculated value shall be rounded to the nearest 5 MPa. For USC units, the calculated value shall be rounded to the nearest 100 psi.
b. For grades > L625 or X90, Rp0,2 applies.
c. Above limit applies for pipe with D > 323,9 mm (12.750 in).
d. For intermediate grades, the specified minimum tensile strength for the weld seam shall be the same value as was determined for the pipe body using footnote a).
e. For pipe requiring longitudinal testing, the maximum yield strength shall be ≤ 495 MPa (71 800 psi).
f. The specified minimum elongation, Af, shall be as determined with following equation:
g. Lower values of Rt0,5/Rm may be specified by agreement.
h. For grades > L625 or X90, Rp0,2 /Rm applies. Lower values of Rp0,2 /Rm may be specified by agreement.
Mechanical Properties for API 5L Sour Service Pipe
The strength value is same as PSL2.
API 5L Line Pipe Test Methods
Hydrostatic Test
a. Jointers need not be hydrostatically level, provided that the portions of pipe used in making the jointers were successfully hydrostatically tested prior to the joining operation.
b. Except the previous situation, the pipe shall withstand the hydrostatic test without leakage through the weld seam or the pipe body.
Bend test
Cracks should not occur in any part of the sample and opening of weld shall not occur as well.
Please Note: For all bend test, the weld extends to a distance of 6.4 mm (0.25 in) on each side of fusion line.
Flattening Test
The flattening test method is used to verify the deformation performance of line pipe to the specified size, and display its defects. According to the stress and deformation characteristics of the specimen during the flattening process, the flattening test shall show the resistance to longitudinal cracking and circumferential cracking of the pipe, and display its internal defects and surface defects.
Other than above three common tests there are other tests that required in each circumstances.
Guided-bend test
CVN impact test for PSL2 pipe (including pipe body tests, pipe weld and HAZ tests)
DWT test for PSL2 welded pipe
Surface Conditions, Imperfections and Defects Appearances
All API 5L pipes shall be free from defects, cracks, sweats and leaks.
More defects as:
Undercuts in SAW and COW pipes.
Arc burns
Laminiations
Geometric deviations
Hard spots
Other surface imperfections (Defects depth more than 0.125 thickness or ≤ 0.125 wall thickness refers to Clauses C in API 5L.)
API 5L Pipe Sizes and Tolerances
Tolerances for diameter and out of roundness
Tolerances for wall thickness
Tolerances for pipe lengths
API 5L pipe length tolerances shall be complied as following conditions:
a. Random length shall be delivered as below table 12.
b. Approximate lengths shall be delivered as tolerances of +/- 500 mm.
Order Information for API 5L pipe
a. Quantity in meters or in tons. Total meters or total pieces.
b. PSL1 or PSL2 (N/M/Q/NS/MS/QS), Sour Services, Onshore/Offshore
c. Pipe Types (Seamless or welded, EW, ERW, HFW, SAW, LSAW, HSAW, SSAW)
d. Reference documents to API 5L.
e. Steel Grade
f. OD (Outside diameter) and WT (pipe wall thickness)
g: Length and length type (Double random length / Single random length / Fixed length / Approximate length)
h. Individual annexes applicability of confirmation
Additional Information
Following additional information also could be included in the PO in different situations.
• Pipe designation
• Chemical composition for intermediate grades
• Carbon equivalent limits
• Diameter or round tolerances for special size pipe
• Jointer welds
• Ends type
• Repairs requirements
• CVN impact test
• DWT test
• Hardness test
• Pipe markings and end colors
And etc.
Traceability
For PSL1 pipe, manufacturer shall establish and follow documented procedures to maintain
a. The heat identity until all related chemical tests are performed and complied the required specifications.
b. Test unit identity until all related mechanical tests are performed and complied with the related specifications.
For PSL2 pipe, Besides above terms, such documents shall provide means for tracing any length of the pipe to the proper test unit, including the related chemical and mechanical test results.
API 5L Line Pipe History and Milestones
Before API 5L pipe standard generated
1834 First cast iron pipe made at US (Millville, NJ)
1856 Converter steel making technology developed
1858 First successful oil well established in Titusivlle, PA
1863 Screwed couplings used in pipeline connections
1863 Pipe is made in wrought iron with furnace lap-welded seams
1893 First 30 inch dia pipe made in lap-welded
1899 First large diameter seamless steel pipe in 20 inch is made, thickness at 5/8 inch
1917 11 mile pipeline is using electric metal arc welding
1919 API (American Petroleum Institute) is charted.
1924 Electric resistance welding with direct or low frequency current is invented
1925 Large diameter seamless pipe in 24" diameter is available
1927 Electric flash welded pipe is developed
After API 5L released
1928 First API 5L standard for manufacturing line pipe appears, covers furnace butt-welded pipe, furnace lap-welded pipe, seamless pipe. Minimum YS 172 Mpa 25000 psi, maximum 310 Mpa 45000 psi. Including material for three Grade A25, A, B, minimum yield strength was 172 Mpa, 207 Mpa, and 241 Mpa.
1931 API 5L pipe specification included ERW pipe (electric resistance welded pipe)
1933 Large diameter steel pipe mostly adopted electric arc girth welding
1944 Electric flash-welded pipe added in API 5L
1946 30 inch large diameter single submerged-arc-welding pipe begins
1948 Double submerged-arc-welded pipe (DSAW pipe) appears
1948 Release API 5LX standard, covers minimum yield strength material in 289 Mpa (42000 psi).
1953 API 5L Grade X46 and X52 pipe added
1962 Furnace lap-welded pipe removed from API 5L pipe, basic oxygen steel making processes accepted.
1963 Nondestructive inspection methods starts to use in API 5L pipe specification
1966 API 5L Grade X60 pipe appears
1969 Supplemental requirements for toughness test added in API 5L
1973 API 5L Grade X70 steel pipe appears
1983 API 5L and API 5LX combined in API 5L.
1985 Grade X80 pipe appears
2000 Minimum level fracture toughness made mandatory in API 5L
Before 2000, Grade X70 pipe used in pipelines total quantity at 40%, Grade X65 and X60 was at about 30% each, small diameter pipelines also choose to Grade X52 pipe, which mostly at ERW type.
API SPEC 5L and ISO 3183
About API SPEC 5L 2018 – 46th Edition of API Pipe Standard
This version was started from April 2018 and effective at 1th, May, 2019.
ISO 3183 standard specification for line pipe
In 2007, ISO and API did a joint release for ISO 3183:2007/API SPEC 5L 44th, to complete a international standard worldwide. Until 2012, United States claimed about the intellectual property right, so API terminated the cooperation with ISO, and no longer making standards for ISO. But the latest version of ISO 3183:2012 or API 5L 2012 still a union achievement, except API LOGO and onshore line pipe specification for European, the other content was all the same.
Differences between API 5L 45th edition and previously edition
The mainly difference between 45th Edition with previously is to add 2 additional appendix: European onshore pipeline for PSL2 pipe order specification, (Annex M). And Equations for threaded and coupled pipe and background equations for guded bend and CVN test specimens (Annex P). For the other content has a little difference in related standards, manufacturing technology, performances norm, inspection methods, besides adjustment of text expression. New version of API 5L 2012 is more completely, and scientific.
API 5L Pipe Application
Modern API 5l steel line pipe belongs to low carbon or ultra-low carbon micro alloy steel. It is high technology and high value-added product.
The steel line pipe production has almost applied to all new technology achievement in metallurgy field nearly 20 years.
At present, the development trend of line pipe engineering is large diameter, high pressure gas transportation, high cold and corrosion service environment, thick wall of submarine pipeline etc.
Therefore, API 5L steel pipe should have high strength, high toughness and brittle fracture, and good weld ability, and suitable for sour services and in H2S environment with anti-corrosion performances.
Source: https://www.octalsteel.com/api-5l-pipe-specification
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