API 5L PSL-2
API 5L PSL-2
API 5L PSL-2 is one of the levels in the API 5L standard indicates the minimum requirements that line pipe products must meet to be compliant with the standard. PSL-1 is the entry-level, and it covers basic chemical and mechanical properties, such as strength and toughness. PSL-2 is the higher level, and it has stricter requirements for chemical composition, mechanical properties, weldability, and nondestructive testing. To meet the PSL-2 quality requirements, manufacturers must undergo a more stringent testing regime during production. As a result, products that are certified to PSL-2 are typical of a higher quality than those certified to PSL-1.
The American Petroleum Institute‘s API 5L specification is for Line Pipe used in pipelines for transporting oil, natural gas, and water. It is the most common specification used for this purpose. The API 5L covers two different product specifications; one for PSL 1 Grades A through X70, and the other for PSL 2 Grades B through X80.
What is the Difference between API 5L PSL-1 and PSL-2?
There are two levels of pipe in the API 5L specification: PSL-1 and PSL-2. PSL-1 and PSL-2 levels are determined by different tests measuring various properties. The levels indicate the strictness of quality requirements. PSL-1 levels are less strict than PSL-2 levels. For example, the chemical test for PSL-1 levels measures fewer elements than the chemical test for PSL-2 levels. The mechanical tests for PSL-1 levels (tensile, yield, elongation) have lower requirements than the mechanical tests for PSL-2 levels. The test frequency is also higher for PSL-2 levels than for PSL-1 levels. In general, PSL-2 levels indicate a higher quality product than PSL-1 levels.
Chemical Composition for API 5L PSL-2 Pipe with t ≤ 0.984”
|Steel Grade (Steel Name)||Mass Fraction, Based on Heat and Product Analyses % max||Carbon Equlvalent a % max|
|C b||Si||Mn b||P||S||V||Nb||Ti||Other||CE iiw||CE pcm|
|L245R or BR||0.24||0.4||1.2||0.025||0.015||c||c||0.04||e,l||0.43||0.25|
|L290R or X42R||0.24||0.4||1.2||0.025||0.015||0.06||0.05||0.04||e,l||0.43||0.25|
|L245N or BN||0.24||0.4||1.2||0.025||0.015||c||c||0.04||e,l||0.43||0.25|
|L290N or X42N||0.24||0.4||1.2||0.025||0.015||0.06||0.05||0.04||e,l||0.43||0.25|
|L320N or X46N||0.24||0.4||1.4||0.025||0.015||0.07||0.05||0.04||d,e,l||0.43||0.25|
|L360N or X52N||0.24||0.45||1.4||0.025||0.015||0.1||0.05||0.04||d,e,l||0.43||0.25|
|L390N or X56N||0.24||0.45||1.4||0.025||0.015||0.1 t||0.05||0.04||d,e,l||0.43||0.25|
|L415N or X60N||0.24 t||0.45 t||1.4 t||0.025||0.015||0.1 t||0.05 t||0.04 t||g,h l||As agreed|
|L245Q or BQ||0.18||0.45||1.4||0.025||0.015||0.05||0.05||0.04||e,l||0.43||0.25|
|L290Q or X42Q||0.18||0.45||1.4||0.025||0.015||0.05||0.05||0.04||e,l||0.43||0.25|
|L320Q or X46Q||0.18||0.45||1.4||0.025||0.015||0.05||0.05||0.04||e,l||0.43||0.25|
|L360Q or X52Q||0.18||0.45||1.5||0.025||0.015||0.05||0.05||0.04||e,l||0.43||0.25|
|L390Q or X56Q||0.18||0.45||1.5||0.025||0.015||0.07||0.05||0.04||d,e,i||0.43||0.25|
|L415Q or X60Q||0.18 t||0.45 t||1.7 t||0.025||0.015||g||g||g||h,l||0.43||0.25|
|L450Q or X65Q||0.18 t||0.45 t||1.7 t||0.025||0.015||g||g||g||h,l||0.43||0.25|
|L485Q or X70Q||0.18 t||0.45 t||1.8 t||0.025||0.015||g||g||g||h,l||0.43||0.25|
|L555Q or X80Q||0.18 t||0.45 t||1.9 t||0.025||0.015||g||g||g||i,j||As agreed|
|L625Q or X90Q||0.16 t||0.45 t||1.9||0.020||0.01||g||g||g||j,k||As agreed|
|L690Q or X100Q||0.16 t||0.45 t||1.9||0.020||0.01||g||g||g||j,k||As agreed|
|L245M or BM||0.22||0.45||1.2||0.025||0.015||0.05||0.05||0.04||e,l||0.43||0.25|
|L290M or X42M||0.22||0.45||1.3||0.025||0.015||0.05||0.05||0.04||e,l||0.43||0.25|
|L320M or X46M||0.22||0.45||1.3||0.025||0.015||0.05||0.05||0.04||e,l||0.43||0.25|
|L360M or X52M||0.22||0.45||1.4||0.025||0.015||d||d||d||e,l||0.43||0.25|
|L390M or X50M||0.22||0.45||1.4||0.025||0.015||d||d||d||e,l||0.43||0.25|
|L415M orX80M||0.12 t||0.45 t||1.6 t||0.025||0.015||g||g||g||h,l||0.43||0.25|
|L450M or X65M||0.13 t||0.45 t||1.6 t||0.025||0.015||g||g||g||h,l||0.43||0.25|
|L485M or X70M||0.14 t||0.45 t||1.7 t||0.025||0.015||g||g||g||h,l||0.43||0.25|
|L555M or X80M||0.15 t||0.45 t||1.85 t||0.025||0.015||g||g||g||i,l||0.43 t||0.25|
|L625M or X90M||0.1||0.55 t||2.1 t||0.020||0.01||g||g||g||i,l||–||1.25|
|L690M or 100M||0.1||0.55 t||2.1 t||0.020||0.01||g||g||g||i,j||2.25|
|L830M or 120M||0.1||0.55 t||2.1 t||0.020||0.01||g||g||g||i,j||3.25|
a Based upon product analysis. For seamless pipe with t >20.0 mm (0.787 in), the CE limits shall be as agreed. The CE iiw limits apply if C > 0.12 % and the CE pcm limits apply if C< 0.12 %
b For each reduction of 0.01 % below the specified maximum for C, an increase of 0.05 % above the specified maximum for Mn is permissible, up to a maximum of 1.65 % for grades ≥L245 or B. but ≤ L360 or X52; up to a maximum of 1.75 % for grades > L360 or X52.but < L485 or X70; up to a maximum of 2.00 % for grades ≥ L485 or X70. but ≤L555 or X80; and up to a maximum of 2.20 % for grades > L555 or X80.
c Unless otherwise agreed.Nb + V< 0.06 %
e Unless otherwise agreed. Cu ≤0.50 %; Ni ≤ 0.30 %; Cr ≤ 0.30% and Mo≤ 0.15 %.
Mechanical Property for API 5L PSL-2 Pipes
|Pipe Grade||Pipe Body of Seamless and Welded Pipe||Weld Seam of HFW,SAW, and COW Pipe|
|Yield Strength a|
|Tensile Strength a|
|Elongation(on 50mm or 2in.)|
|Tensile Strength b|
|L245R or BR|
L245N or BN
L245Q or BQ
L245M or BM
|L290R or X42R|
L290N or X42N
L290Q or X42Q
L290M or X42M
|L320N or X46N|
L320Q or X46Q
L320M or X46M
|L360N or X52N|
L360Q or X52Q
L360M or X52M
|L390N or X56N|
L390Q or X56Q
L390M or X56M
|L415N or X60N|
L415Q or X60Q
L415M or X60M
|L450Q or X65Q|
L450M or X65M
|L485Q or X70Q|
L485M or X70M
|L555Q or X80Q|
L555M or X80M
|L625M or X90M||625(90,600)||775(112,400)||695(100,800)||915(132,700)||0.95||f||695(100,800)|
|L625Q or X90Q||625(90,600)||775(112,400)||695(100,800)||915(132,700)||0.97g||f||–|
|L690M or X100M||690(100,100)b||840(121,800)b||760(110,200)||990(143,600)||0.97h||f||760(110,200)|
|L690Q or X100Q||690(100,100)b||840(121,800)b||760(110,200)||990(143,600)||0.97h||f||–|
|L830M or X120M||830(120,400)b||1050(152,300)b||915(132,700)||1145（166,100）||0.99h||f||915(132.700)|
a For intermediate grades,the difference between the specified maximum yield strength and the specified minimum yield stringent shall be as given in the table for the next higher grade, and the difference between the specified minimum tensile strength and the specified minimum yield strength 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 Sl 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 This 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 using the following equation:
C is 1940 for calculations using Sl units and 625,000 for calculations using USC units
Axc is the applicable tensile test piece cross-sectional area, expressed in square millimeters (square inches), as follows:
1)for circular cross-section test pieces, 130 mm² (0.20 in.²) for 12.7 mm (0.500 in,) and 8.9 mm (0.350 in,) diameter test pieces; 65 mm²(0.10 in.² ) for 6.4 mm (0.250 in.) diameter test pieces
2) for ful-section test pieces, the lesser of a) 485 mm²(0.75 in.²) and b) the cross-sectional area of the test piece, derived using the specified outside diameter and the specified wall thickness of the pipe, rounded to the nearest10 mm²(0.01 in.²)
3)for strip test pieces, the lesser of a) 485 mm²(0.75 in.²) and b) the cross-sectional area of the test piece, derived using the specified width of the test piece and the specified wall thickness of the pipe, rounded to the nearest10 mm²(0.01 in.²);
U is the specified minimum tensile strength, expressed in megapascals (pounds per square inch)
g Lower values of Rto.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.
Dimensions and Sizes of API 5L psl-2 Line Pipe
When purchasing an API 5L PSL-2 line pipe, it is crucial to check that the pipe meets the required standards. One way to do this is to refer to the dimensions and masses of API 5L line pipes specified in ISO 4200 and ASME B36.10M. These standards provide guidance for different size pipes and specify the wall thickness of each size. Checking that a particular pipe meets the requirements in these tables will help to ensure that it is the right size and has the correct wall thickness. Doing so is essential for ensuring that the pipe will be compatible with the rest of the system and function properly.
|NPS||O. D.||W. T.|
API 5L PSL-2 Pipe Delivery Conditions
|PSL||Delivery Condition||Steel Grade|
|API PSL-2||As-rolled||BR, X42R|
|Normalizing rolled, normalizing formed, normalized or normalized and tempered||BN, X42N, X46N, X52N, X56N, X60N|
|Quenched and tempered||BQ, X42Q, X46Q, X56Q, X60Q, X65Q, X70Q, X80Q, X90Q, X100Q|
|Thermomechanical rolled or thermomechanical formed||BM, X42M, X46M, X56M, X60M, X65M, X70M, X80M|
|Thermomechanical rolled||X90M, X100M, X120M|
|The suffice (R, N, Q or M) for PSL2 grades, belongs to the steel grade||-|
Test and inspection of API 5L psl-2 Line pipes
- Hydrostatic Test
The hydrostatic test is a water-based test used to find leaks in weld seams and pipe body. To conduct the test, water is pumped into the pipeline at a pressure that is greater than the operating pressure of the pipeline. The water pressure is then held for a period of time while the pipeline is monitored for leaks. If no leaks are detected, the pipeline passes the hydrostatic test and can be put into service. However, if a leak is found, the pipeline must be repaired before it can be used. The hydrostatic test is an important part of pipeline production, as it helps to ensure that pipelines are safe and reliable.
- Bend Test
The bend test is a quality control check that is carried out during the production of metal pipes. The test involves taking a sample of the pipe and then bending it to a set degree. This is done to check that the pipe is not too brittle and that it will not crack under pressure. The bend test is an important part of quality control as it helps to ensure that the finished product is safe and fit for its purpose.
- Flattening Test
The flattening test is a destructive test that is used to determine the resistance of a material to crack propagation. The test specimen is supported at two ends and a load is applied perpendicular to the specimen. The crack propagates through the specimen until it reaches the support, at which point the specimen fractures. The flattening test is used to assess the crack propagation characteristics of materials such as pipelines, which are subjected to both longitudinal and circumferential stresses. The results of the flattening test can be used to predict the service life of a pipeline and to design a pipe with improved resistance to crack propagation.
- CVN Impact Test
In pipeline production, an impact test is an essential quality control measure. The test is used to assess the pipe body, weld seam, and heat-affected zone for potential vulnerabilities. The test involves exposing the sample to extreme temperatures and then measuring the amount of energy required to break the material. This information is used to determine the strength and durability of the pipeline. Impact testing is an important part of quality control in pipeline production, and it helps to ensure that the finished product is safe and reliable.
DWTT is an impact test used to measure the strength of metal pipes. The test involves dropping a weight onto the pipe, and then measuring the amount of deformation that occurs. DWTT is often used for large diameter pipes, as it can provide a more accurate assessment of impact strength than other methods. DWTT tests are typically conducted using a variety of different weights, in order to assess the impact strength of the pipe at different points. The results of DWTT testing can be used to improve the impact resistance of pipes, and to help ensure that they can withstand the rigors of production.