API 5L

api-5l-line-pipe-pipeline

API 5L

API 5L is a standard specification for line pipe that which American Petroleum Institute (API) develops and it provides the requirements for the manufacture of two product levels ( API 5L PSL1 and API 5L PSL2) of seamless and welded steel pipe for the use of the global petroleum industry, especially in the transport of crude oil, natural gas, and water. 

API 5L Line Pipe specification 46th Edition, initially published in 1965, outlines chemical, mechanical, and hydrostatic testing criteria. Manufacturers must meet API pipe standards requirements and undergo audits to obtain a license for API 5L compliance, allowing them to showcase the API monogram on their products. License renewal every three years ensures continued adherence to quality assurance programs.

Thankfully, TUSPIPE has an API standard certificate and our api 5l line pipe consistently follows this standard!

Why choose tuspipe API 5L

pipe-icon

TUSPIPE stands tall as an indispensable ally for the oil and gas industry. Our pipes serve as the very lifelines that efficiently channel vital resources. Understanding the criticality of high-performing pipes in this sector, we engineer our products to withstand the rigorous demands and aggressive environments typical of oil and gas applications. Our pipes are compliant with stringent API 5L specifications, ensuring unmatched strength and durability. Our heat treatment and inspection capabilities further fortify welds and eradicate leaks. Moreover, TUSPIPE’s anti-corrosion services, such as FBE, 3LPE, and 3LPP coatings, guarantee long-lasting resilience against corrosion – a non-negotiable necessity for oil and gas pipelines.

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Steel Grades of API 5L

API’s steel grades for line pipe standardize material chemistry and mechanical properties, ensuring adherence to set requirements. Common API 5L  grade B, X42, X52, X60, and X65, with the number following ‘X’ denoting minimum yield strength in PSL. Typically used in oil and gas transport, line pipes find applications in water transport, construction, and various industries, emphasizing the importance of steel grades in selecting suitable materials.”

There are multiple grades of API 5L available, each with different yield strength and tensile strength ratings. The most common grades for API 5L line pipes are:

API 5L transporting categories A, B, or X fluids must be constructed from steel materials that have an area under the stress-strain curve that meets the requirements specified in the material standard. The API 5L specified minimum yield and tensile strengths “represent the point on the Stress

Grade Minimum Yield Strength (ksi) Minimum Ultimate Tensile Strength (ksi)
 X52 52 66
X56 56 71
X60 60 75
X65 65 77

Dimensions and Size RANGE of API 5L

Before purchasing an API 5L , it is important to check the size and dimensions of the line pipe to ensure that it meets the required standards. The dimensions and masses of API 5L  are specified in ISO 4200 and ASME B36.10M. These standards provide a guide for different size API 5L pipes and specify the wall thickness of each size. To check if a particular pipe meets the required standards, refer to these tables. Doing so will help to ensure that the API 5L pipe is the right size and has the correct wall thickness.

NPS O. D. W. T.
DN Inch mm SCH5S SCH10S SCH10 SCH20 SCH30 SCH40 SCH60 SCH80 SCH100 SCH120 SCH140 SCH160 Sth XS XXS
50 2″ 60.3 1.65 2.77 3.91 5.54 8.74 3.91 5.54 11.07
65 2 1/2″ 73 2.11 3.05 5.16 7.01 9.53 5.16 7.01 14.02
80 3″ 88.9 2.11 3.05 5.49 7.62 11.13 5.49 7.52 15.24
90 3 1/2″ 101.6 2.11 3.05 5.74 8.08 5.74 8.08
100 4″ 114.3 2.11 3.05 6.02 8.58 11.13 13.49 6.02 8.56 17.12
125 5″ 141.3 2.77 3.4 6.55 9.53 12.7 15.88 6.55 9.53 18.05
150 6″ 168.3 2.77 3.4 7.11 10.97 14.27 18.26 7.11 10.97 21.95
200 8″ 219.1 2.77 3.76 6.35 7.04 8.18 10.31 12.7 15.09 18.26 20.62 23.01 8.18 12.7 22.23
250 10″ 273.1 3.4 4.19 6.35 7.8 9.27 12.7 15.09 18.26 21.44 25.4 28.58 9.27 12.7 25.4
300 12″ 323.9 3.96 4.57 6.35 8.38 10.31 14.27 17.48 21.44 25.4 28.58 33.32 9.53 12.7 25.4
350 14″ 355.5 3.96 4.78 6.35 7.92 9.53 11.13 15.09 19.05 23.83 27.79 31.75 35.71 9.53 12.7
400 16″ 406.4 4.19 4.78 6.35 7.92 9.53 12.7 16.66 21.44 26.19 30.96 36.53 40.49 9.53 12.7
450 18″ 457.2 4.19 4.78 6.35 7.92 11.13 14.27 19.05 23.83 39.36 34.93 39.67 45.24
500 20″ 508 4.78 5.54 6.35 9.53 12.7 15.09 20.62 26.19 32.54 38.1 44.45 50.01
550 22″ 558.8 4.78 5.54 6.35 9.53 12.7 22.23 28.58 34.93 41.28 47.63 53.98
600 24″ 609.6 5.54 6.35 6.35 9.53 14.27 17.48 24.61 30.96 38.89 46.02 52.37 59.54

Chemical composition of API 5L

Steel GradeMass fraction, % based on heat and product analyses a,g
CMnPSVNbTi
max bmax bmaxmaxmaxmaxmax
Seamless Pipe
A0.220.90.030.03
B0.281.20.030.03c,dc,dd
X420.281.30.030.03ddd
X460.281.40.030.03ddd
X520.281.40.030.03ddd
X560.281.40.030.03ddd
X600.28 e1.40 e0.030.03fff
X650.28 e1.40 e0.030.3fff
X700.28 e1.40 e0.030.03fff
Welded Pipe
A0.220.90.030.03
B0.261.20.030.03c,dc,dd
X420.261.30.030.03ddd
X460.261.40.030.03ddd
X520.261.40.030.3ddd
X560.261.40.30.03ddd
X600.26 e1.40 e0.030.03fff
X650.26 e1.45 e0.030.03fff
X700.26e1.65 e0.030.03fff
a. Cu ≤ = 0.50% Ni; ≤ 0.50%; Cr ≤ 0.50%; and Mo ≤ 0.15%,
b. For each reduction of 0.01% below the specified maximum concentration for carbon, an increase of 0.05% above the specified maximum concentration 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; and up to a maximum of 2.00% for grade L485 or X70.,
c. Unless otherwise agreed NB + V ≤ 0.06%,
d. Nb + V + TI ≤ 0.15%,
e. Unless otherwise agreed.,
f. Unless otherwise agreed, NB + V = Ti ≤ 0.15%,
g. No deliberate addition of B is permitted and the residual B ≤ 0.001%
Steel GradeMass fraction, % based on heat and product analysesCarbon Equiv a
CSiMnPSVNbTiOtherCE IIWCE Pcm
max bmaxmax bmaxmaxmaxmaxmaxmaxmax
Seamless  Pipe
BR0.240.41.20.0250.015cc0.04e,l0.0430.25
X42R0.240.41.20.0250.0150.060.050.04e,l0.0430.25
BN0.240.41.20.0250.015cc0.04e,l0.0430.25
X42N0.240.41.20.0250.0150.060.050.04e,l0.0430.25
X46N0.240.41.40.0250.0150.070.050.04d,e,l0.0430.25
X52N0.240.451.40.0250.0150.10.050.04d,e,l0.0430.25
X56N0.240.451.40.0250.0150.10f0.050.04d,e,l0.0430.25
X60N0.24f0.45f1.40f0.0250.0150.10f0.05f0.04fg,h,lAs agreed
BQ0.180.451.40.0250.0150.050.050.04e,l0.0430.25
X42Q0.180.451.40.0250.0150.050.050.04e,l0.0430.25
X46Q0.180.451.40.0250.0150.050.050.04e,l0.0430.25
X52Q0.180.451.50.0250.0150.050.050.04e,l0.0430.25
X56Q0.180.45f1.50.0250.0150.070.050.04e,l0.0430.25
X60Q0.18f0.45f1.70f0.0250.015gggh,l0.0430.25
X65Q0.18f0.45f1.70f0.0250.015gggh,l0.0430.25
X70Q0.18f0.45f1.80f0.0250.015gggh,l0.0430.25
X80Q0.18f0.45f1.90f0.0250.015gggi,jAs agreed
X90Q0.16f0.45f1.90.020.01gggj,kAs agreed
X100Q0.16f0.45f1.90.020.01gggj,kAs agreed
Welded Pipe
BM0.220.451.20.0250.0150.050.050.04e,l0.0430.25
X42M0.220.451.30.0250.0150.050.050.04e,l0.0430.25
X46M0.220.451.30.0250.0150.050.050.04e,l0.0430.25
X52M0.220.451.40.0250.015ddde,l0.0430.25
X56M0.220.45f1.40.0250.015ddde,l0.0430.25
X60M0.12f0.45f1.60f0.0250.015gggh,l0.0430.25
X65M0.12f0.45f1.60f0.0250.015gggh,l0.0430.25
X70M0.12f0.45f1.70f0.0250.015gggh,l0.0430.25
X80M0.12f0.45f1.85f0.0250.015gggi,j.043f0.25
X90M0.10.55f2.10f0.020.01gggi,j0.25
X100M0.10.55f2.10f0.020.01gggi,j0.25
a. SMLS t>0.787”, CE limits shall be as agreed. The CEIIW limits applied fi C > 0.12% and the CEPcm 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%,
d. Nb = V = Ti ≤ 0.15%,
e. Unless otherwise agreed, Cu ≤ 0.50%; Ni ≤ 0.30% Cr ≤ 0.30% and Mo ≤ 0.15%,
f. Unless otherwise agreed,
g. Unless otherwise agreed, Nb + V + Ti ≤ 0.15%,
h. Unless otherwise agreed, Cu ≤ 0.50% Ni ≤ 0.50% Cr ≤ 0.50% and MO ≤ 0.50%,
i. Unless otherwise agreed, Cu ≤ 0.50% Ni ≤ 1.00% Cr ≤ 0.50% and MO ≤ 0.50%,
j. B ≤ 0.004%,
k. Unless otherwise agreed, Cu ≤ 0.50% Ni ≤ 1.00% Cr ≤ 0.55% and MO ≤ 0.80%,
l. For all PSL 2 pipe grades except those grades with footnotes j noted, the following applies. Unless otherwise agreed no intentional addition of B is permitted and residual B ≤ 0.001%.

Mechanical Properties of API 5L

Pipe Grade Pipe body of seamless and welded pipes Weld seam of EW, SAW and COW pip
Yield strength R10,5MPa(psi) minimum Tensile strength RmMPa(psi) minimum Elongation Af% minimum Tensile strength RmMPa(psi) minimum
L175 or A25 175 (25 400) 310 (45 000) c 310 (45 000)
L175P or A25P 175 (25 400) 310 (45 000) c 310 (45 000)
L210 or A 210 (30 500) 335 (48 600) c 335 (48 600)
L245R or BR L245 or B 245 (35 500) 415 (60 200) c 415 (60 200)
L290R or X42R L290 or X42 290 (42 100) 415 (60 200) c 415 (60 200)
L320 or X46 320 (46 400) 435 (63 100) c 435 (63 100)
L360 or X52 360 (52 200) 460 (66 700) c 460 (66 700)
L390 or X56 390 (56 600) 490 (71 100) c 490 (71 100)
L415 or X60 415 (60 200) 520 (75 400) c 520 (75 400)
L450 or X65 450 (65 300) 535 (77 600) c 535 (77 600)
L485 or X70 485 (70 300) 570 (82 700) c 570 (82 700)

a. For intermediate grades, the difference between the specified minimum tensile strength and the specified minimum yield strength for the pipe body shall be as given in the table for the next higher grade. 

b. 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). 

c. The specified minimum elongation, Af expressed in percent and rounded to the nearest percent, shall be as determined using the following equation;

api-af
Api-Af

where

C is 1 940 for calculations using SI 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:

—– for circular cross-section test pieces, 130 mm2 (0.20 in2) for 12,5 mm (0.500 in) and 8,9 mm (0.350 in) diameter test pieces; and 65 mm2(0.10 in2) for 6,4 mm (0.250 in) diameter test pieces;

—— For full-section test pieces, the lesser of a) 485 mm2 (0.75 in2) 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 nearest 10 mm2 (0.01 in2);

—– for strip test pieces, the lesser of a) 485 mm2 (0.75 in2) 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 nearest 10 mm2(0.01 in2);

U is the specified minimum tensile strength, expressed in megapascals (pounds per square inch).

Pipe gradePipe body of seamless and welded pipesWeld seam of HFW, SAW and COW pipes
Yield strength
Rto,5b
MPa (psi)
Tensile strength
Rm
MPa (psi)
Ratioa,b,c
Rto,5/Rm
Elongation
Af
%
Tensile strength
Rm
MPa (psi)
minimummaximumminimummaximummaximumminimumminimum
L245R or BR
L245N or BN
L245Q or BQ
L245M or BM
245
(35 500)
450 e
(65 300) e
415
(60 200)
760
(110 200)
0,93f415
(60 200)
L290R or X42R
L290N or X42N
L290Q or X42Q
L290M or X42M
290
(42 100)
495
(71 800)
415
(60 200)
760
(110 200)
0,93f415
(60 200)
L320N or X46N
L320Q or X46Q
L320M or X46M
320
(46 400)
525
(76 100)
435
(63 100)
760
(110 200)
0,93f435
(63 100)
L360N or X52N
L360Q or X52Q
L360M or X52M
360
(52 200)
530
(76 900)
460
(66 700)
760
(110 200)
0,93f460
(66 700)
L390N or X56N
L390Q or X56Q
L390M or X56M
390
(56 600)
545
(79 000)
490
(71 100)
760
(110 200)
0,93f490
(71 100)
L415N or X60N
L415Q or X60Q
L415M or X60M
415
(60 200)
565
(81 900)
520
(75 400)
760
(110 200)
0,93f520
(75 400)
L450Q or X65Q
L450M or X65M
450
(65 300)
600
(87 000)
535
(77 600)
760
(110 200)
0,93f535
(77 600)
L485Q or X70Q
L485M or X70M
485
(70 300)
635
(92 100)
570
(82 700)
760
(110 200)
0,93f570
(82 700)
L555Q or X80Q
L555M or X80M
555
(80 500)
705
(102 300)
625
(90 600)
825
(119 700)
0,93f625
(90 600)
L625M or X90M625
(90 600)
775
(112 400)
695
(100 800)
915
(132 700)
0,95f695
(100 800)
L690M or X100M690
(100 100)
840
(121 800)
760
(110 200)
990
(143 600)
0,97 gf760
(110 200)
L830M or X120M830
(120 400)
1 050
(152 300)
915
(132 700)
1 145
(166 100)
0,99 gf915
(132 700)

a. For intermediate grades, the difference between the specified maximum yield strength and the specified minimum yield strength 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 lower than Grade L555 or X80, the tensile strength shall be ≤ 760 MPa (110  200 psl). 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.   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 with D<219,1 mm (8.625 in), 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:    

api 5l af
Api 5L Af

 

Where

 C        is   1 940 for calculations using SI units and 625 000 for calculations using USC units;

 A xc    is the applicable tensile test piece cross-sectional area, expressed in square millimeters (square inches), as follows:

  —- for circular cross-section test pieces, 130 mm2 (0.20 in2)  for 12,5 mm (0.500 in) and 8,9 mm (0.350 in) diameter test pieces;  and 65 mm2 ( 0.10 in2)   for 6,4 mm (0.250 in) diameter  test pieces;

  —- for full-section test pieces, the lesser of a) 485 mm2 (0.75 in2) 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 nearest 10 mm2 (0.01 in2)

 —- for strip test pieces, the lesser of a) 485 mm2(  0.75 in2 )  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  API 5L pipe, rounded to the nearest_10 mm2 (0.01 in2 );

U  is the specified minimum tensile strength, expressed in megapascals (pounds per square inch).

api 5l specification:Production Tolerances

- API 5L Outside Diameter and Out of Roundness Tolerance

Specified Outside Diameter D (in)Diameter Tolerance, inches dOut-of-Roundness Tolerance in
Pipe except the end aPipe end a,b,cPipe except the End aPipe End a,b,c
SMLS PipeWelded PipeSMLS PipeWelded Pipe
< 2.375-0.031 to + 0.016–  0.031 to + 0.0160.0480.036
≥2.375 to 6.625+/- 0.0075D–  0.016 to + 0.0630.020D for0.015D for
n/t≤75n/t≤75
By agreement forBy agreement for
n/t≤75n/t≤75
>6.625 to 24.000+/- 0.0075D+/- 0.0075D, but max of 0.125+/- 0.005D, but max of 0.0630.020D0.015D
>24 to 56+/- 0.01D+/- 0.005D but max of 0.160+/- 0.079+/- 0.0630.015D for but max of 0.0600.01D for but max of 0.500
ForFor
n/t≤75n/t≤75
By agreementBy agreement
forfor
n/t≤75n/t≤75
>56As agreed
a.        The API 5L pipe end includes a length of 4 in ate each of the pipe extremities
b.        For SMLS pipe the tolerance apply for t≤0.984in and the tolerances for the thicker pipe shall be as agreed
c.         For expanded pipe with D≥8.625in and for non-expanded pipe, the diameter tolerance and the out-of-roundness tolerance may be determined using the calculated inside diameter or measured inside diameter rather than the specified OD.
d.       For determining compliance to diameter tolerance, the pipe diameter is defined as the circumference of the pipe in any circumferential plane divide by Pi.

- API 5L Wall Thickness Tolerances

Wall thickness t mm (in) Tolerances a mm (in)
Seamless pipe b
≤ 4,0 ( 0.157) + 0,6 (0.024) – 0,5 (0.020)
> 4,0 ( 0.157) to <25,0 (0.984) + 0,150 – 0,125
≥ 25,0 (0.984) +3,7 (0.146) or + 0,1 t, whichever is the greater – 3,0 (0.120) or – 0,1 t, whichever is the greater
Welded pipe c, d
≤ 5,0 (0.197) ± 0,5 (0.020)
> 5,0 (0.197) to <15,0 (0.591) ± 0,1 t
≥ 15,0 (0.591) ±1,5 (0.060)

a   If the purchase order specifief a minus tolerance for wall thickness smaller than the applicable value given in this table, the plus tolerance for wall thickness shall be increased by an amount sufficient to maintain the applicable tolerance range.

b   For API 5L pipe with D ≥ 355,6 mm (14.000 in) and t ≥ 25,0 mm (0.984 in) the wall-thickness tolerance locally may exceed the plus tolerance for wall thickness by an additional 0,05 t, provided that the plus tolerance for mass (see 9.14) is not exceeded.

c   The plus tolerance for wall thickness does not apply to the weld area.

d   See 9.13.2 for additional restrictions.

- API 5L Length Tolerances

According to the requirements outlined in API 5L, random lengths of line pipe shall be delivered within the tolerances given below, and approximate lengths must be delivered within ± 500 mm (20 in.). Additionally, if the supply of jointers is agreed upon, jointers comprising two pieces welded together to make a length shorter than 15.0 m (49.2 ft) may be furnished to a maximum of 5 % of the order item, or as agreed. Jointers comprising three pieces welded together to make a length 15.0 m (49.2 ft) or longer may also be furnished for the entire order item or any portion thereof, though this is limited to a maximum of 5 % of the order item as well. These requirements ensure that API 5L are of the correct length and can be properly joined together when necessary.

Random length designationMinimum lengthMinimum average length for each order itemMaximum length
m (ft)m (ft)m(ft)m(ft)
Threaded-and-coupled pipe
6 (20)4.88 (16.0)5.33 (17.5)6.86 (22.5)
9 (30)4.11 (13.5)8.00 (26.2)10.29 (33.8)
12 (40)6.71 (22.0)10.67 (35.0)13.72 (45.0)
Plain-end pipe   
6 (20)2.74 (9.0)5.33 (17.5)6.86 (22.5)
9 (30)4.11 (13.5)8.00 (26.2)10.29 (33.8)
12 (40)4.27 (14.0)10.67 (35.0)13.72 (45.0)
15 (50)5.33 (17.5)13.35 (43.8)16.76 (55.0)
18 (60)6.40 (21.0)16.00 (52.5)19.81 (65.0)
24 (80)8.53 (28.0)21.34 (70.0)25.91 (85.0)

Test and inspection of API 5L

- Hydrostatic Test

A hydrostatic test is a type of pressure test that is commonly used during the production of line pipes. The test is used to check for leaks in the weld seam or pipe body. To conduct the test, water is pumped into the pipe until it reaches a predetermined pressure. The pipe is then monitored for any leaks. If a leak is detected, the pipe will need to be repaired or replaced. The hydrostatic test is an important quality control measure that helps to ensure the safety and integrity of pipes.

- Bending Test

A bending test is a type of quality control test that is performed during steel pipe production. The purpose of the test is to check for cracks in the welds, as well as to assess the strength of the steel. To perform the test, a sample piece of pipe is bent into a U-shape. The steel is then examined for cracks or other signs of weakness. If any are found, the entire batch of steel pipes will be scrapped and a new batch will be made. However, if the bending test proves successful, the steel pipes will be approved for use.

- Flattening Test

A flattening test is a steel line pipe production test that assesses a steel tube’s resistance to deformation and cracking under stress. It is an important quality control measure that helps ensure the steel used in line pipe products is of the highest possible quality. The test involves applying pressure to a steel tube until it deforms or cracks. The flattening test will reveal the pipe’s resistance to longitudinal and circumferential cracking. The results of the test help determine the steel’s strength and ductility, two important properties for steel used in line pipe applications. Flattening tests are just one of many quality control measures that are used during steel line pipe production, but they play an important role in ensuring the safety and integrity of the final product.

- CVN Impact Test

The CVN impact test is a temperature test that is conducted during pipe production in order to ensure the mechanical properties of the pipe. The test is conducted on three different positions on the pipe: the body, the welding seam, and the heat-affected zone. The results of the test are used to determine the Charpy V-notch impact strength of the pipe. The CVN impact test is an important quality control measure for pipe production, and it is required by the American Petroleum Institute (API) in order to meet its standards.

- DWTT

The DWTT test, or drop-weight tear tests, are specified in the API 5L production specification. In this test, a large weight is dropped onto a pre-weakened point on a sample of pipe. The resulting fracture is examined to ensure that it meets the requirements for ductile fracture behavior. This test is important because it helps to ensure that pipes will be able to withstand the stress of being transported and installed without breaking. As a result, the DWTT test is an essential part of the quality control process for large diameter line pipes.

Inspection Frequency for API 5L

- Inspection Frequency for API 5L PSL 1

No Type of Inspection Type Frequency of Inspection e
1 Heat analysis All pipe One analysis per heat of steel
2 Product analysis SMLS,CW,LFW,HFW,LW.SAW,or COW Two analyses per heat of steel (taken from separate product items)
3 Tensile testing of the pipe body of welded pipe with D ≤ 48.3 mm(1.900 in.),in Grade L175 or A25 CW, LFW,or HFW Once per test unit e of not more than 25 tonnes(28 tons) of pipe
4 Tensile testing of the pipe body of welded pipe with D ≤ 48.3 mm(1.900 in.),in Grade L175P or A25P CW Once per test unit e of not more than 25 tonnes(28 tons) of pipe
5 Tensile testing of the pipe body of welded pipe with D > 48.3 mm(1.900 in.),in Grade L175 or A25 CW,LFW,or HFW Once per test unit of not more than 50 tonnes(55 tons) of pipe
6 Tensile testing of the pipe body of welded pipe with D > 48.3 mm(1.900 in.),in Grade L175P or A25P CW Once per test unit of not more than 50 tonnes(55 tons)of pipe
7 Tensile testing of the pipe body of seamless pipe SMLS Once per test unit of pipe with the same cold-expansion ratio a
8 Tensile testing of the pipe body of welded pipe in grades higher than Grade L175 or A25 LFW,HFW,LW,SAW,or CoW Once per test unit of pipe with the same cold-expansion ratio a
9 Tensile testing of the longitudinal or helical seam weld of welded pipe with D ≥ 219.1 mm (8.625 in.). LFW,HFWLW,SAW,or Cow Once per test unit of pipe with the same cold-expansion ratio a,b,c
10 Tensile testing of the coil/plate end weld of welded pipe with D ≥ 219.1 mm (8.625 in.). SAWH or COWH At least once per 50 coil/plate end welds from pipe with the same cold-expansion ratio a,c,d
11 Bend testing of the longitudinal seam weld of welded pipe with D ≤ 48.3 mm(1.900 in.),in Grade L175, L175P, A25,or A25P CW,LFW,or HFW Once per test unit of not more than 25 tonnes(28 tons) of pipe
12 Bend testing of the longitudinal seam weld of welded pipe with 48.3 mm(1.900 in.)<D ≤ 60.3 mm (2.375 in.).in Grade L175,L175P,A25,or A25P CW,LFW,or HFW Once per test unit of not more than 50 tonnes(55 tons) of pipe
13 Guided-bend testing of the longitudinal or helical seam weld of welded pipe SAW or COW Once per test unit of not more than 50 lengths of pipe of the same grade
14 Guided-bend testing of the coil/plate end weld of welded pipe SAWH or COWH At least once per 50 col/plate end welds from pipe with the same cold expansion ratio a,c,d
15 Guided-bend testing of the longitudinal seam weld of welded pipe with D ≥ 323.9 mm (12.750 in.) LW Once per test unit of not more than 50 lengths of pipe of the same grade
16 Flattening test of welded pipe CW,LFW,HFW,or LW As shown in Figure 6
17 Hardness testing of hard spots in cold-formed welded pipe LFW,HFW,LW,SAW,or COW Any hard spot exceeding 50 mm (2.0 in.) in any direction
18 Hydrostatic testing SMLS,CW,LFW,HFW,LWSAW,or COW Each pipe
19 Macrographic testing of the longitudinal or helical seam weld of welded pipe SAW or COW At least once per operating shift plus whenever any change of pipe size occurs during the operating shift; or if 10.2.5.2 applies, at the beginning of the production of each combination of specified outside diameter and specified wall thickness
20 Metallographic testing of the longitudinal seam weld of welded pipe LFW or HFW excluding full-body normalized pipe At least once per operating shift plus whenever changes of grade, specified outside diameter or specified wall thickness are made:plus whenever excursions from operating heat treatment conditions are encountered
21 Visual inspection SMLS,CW,LFW,HFW,LW,SAW,or COW Each pipe, except as allowed by 10.2.7.2
22 Pipe diameter and out-of-roundness SMLS,CW,LFW,HFW,LW,SAW,or COW At least once per 4 h per operating shift plus whenever any change of pipe size occurs during the operating shift
23 Wall thickness measurement All pipe Each pipe (see 10.2.8.5)
24 Other dimenslonal testing SMLS,CW,LFW,HFW,LW,SAW,or COW Random testing,with the details left tothe discretion of the manufacturer
25 Weighing of pipe with D <141.3 mm (5.563 in.) SMLS,CW,LFW,HFW,LW,SAW,or COW Each pipe or each convenient group of pipe, with the choice being at the discretion of the manufacturer
26 Weighing of pipe with D ≥141.3 mm (5.563 in.) SMLS,CW,LFW,HFW,LW,SAW,or COW Each pipe
27 Length SMLS,CW,LFW,HFW,LW,SAW,or COW Each length of pipe shall be measured, except that pipe made in lengths that are uniform within 30 mm (0.1 ft) need not be individually measured, provided the accuracy of the length is verified at least once per 4 h per operating shift
28 Nondestructive inspection SMLS,CW,LFW,HFW,LW,SAW,or COW In accordance with Annex E

a  The cold-expansion ratio (if applicable) is designated by the manufacturer and is derived using the designated before-expansion outside diameter or circumference and the after-expansion outside diameter or circumference; an increase or decrease in the cold-expansion ratio of more than 0.002 requires the creation of a new test unit.

b   For double-seam pipe, both longitudinal weld seams in the pipe selected to represent the test unit shall be tested.

c   Pipe produced by each welding machine shall be tested at least once per week.

d    Applies only to finished helical seam pipe containing coil/plate end welds.

e  “Test unit””is as defined in 3.1.60.

- Inspection Frequency for API 5L PSL 2

No Type of Inspection Type of Pipe Frequency of Inspection e
1 Hea analysis All pipe One analysis per heat of steel
2 Product analysis SMLS , HFW , SAW , orCOW Two analyses per heat of steel ( taken from separate product items )
3 Tensile testing of the pipe body D ≤141.3 mm (5.563 in .) SMLS , HFW , SAW , or COW Once per test unit of not more than 400 pipes with the same cold – expansion ratio a
4 Tensile testing of the pipe body D >141.3mm(5.563in.) and ≤323.9 body mm (12.750 in .) SMLS , HFW , SAW , or COW Once per test unit of not more than 200 pipes with the same cold – expansion ratio a
5 Tensile testing of the pipe D >323.9 mm (12.750 in .) SMLS,HFW , SAW , or COW Once per test unit of not more than 100 pipes with the same cold – expansion ratio a
6 Tensile testing of the longitudinal or helical seam weld of welded pipe with D ≥219.1 mm (8.625 in .) and ≤323.9 mm (12.750 in .) HFW , SAW , or COW Once per test unit of not more than 200 pipes with the same cold – expansion ratio a . b , c
7 Tensile testing of the longitudinal or helical seam weld of welded pipe with D >323.9 mm (12.750 in .) HFW , SAW , or COW Once per test unit of not more than 100 pipes with the same cold – expansion ratio a , b . c
8 Tensile testing of the coil / plate end weld of welded pipe with D ≥219.1 mm (8.625 in .) SAWH or COWH At least once per 50 coil / plate end welds from pipe with the same cold – expansion ratio a , b , d
9 CVN impact testing of the pipe body of pipe with specified outside diameter and specified wall thickness as given in Table 22 SMLS , HFW , SAW , or COW Once per test unit of pipe with the same cold – expansion ratio a
10 If agreed , CVN impact testing of the longitudinal seam weld of welded pipe specified wall thickness as given in with specified outside diameter and Table 22 HFW Once per test unit of pipe with the same cold – expansion ratio a , b
11 CVN impact testing of the longitudinal or helical seam weld of welded pipe specified wall thickness as given in with specified outside diameter and Table 22 SAW or COW Once per test unit of pipe with the same cold – expansion ratio a . b . c
12 CVN impact testing of the coil / plate end weld of welded pipe with specified outside diameter and specified wall thickness as given in Table 22 SAWH or COWH At least once per 50 coil / plate end welds from pipe with the same cold – expansion ratio a , b , d
13 If agreed , DWT testing of the pipe body of welded pipe with D ≥508 mm (20.000 in .) HFW , SAW , or COW Once per test unit of pipe with the same cold – expansion ratio a
14 Guided – bend testing of the longitudinal or helical seam weld of welded pipe SAW or COW Once per test unit of not more than 50 lengths of pipe with the same cold – expansion ratio
15 Guided – bend testing of the coil / plate end weld of welded pipe SAWH or COWH At least once per 50 coil / plate end welds from pipe with the same cold – expansion ratio a , b . d
16 Flattening test of welded pipe HFW As shown in Figure 6
17 Hardness testing of hard spots in cold -formed welded pipe HFW , SAW , or COw Any hard spot exceeding 50 mm (2.0 in .) in any direction
18 Hydrostatic testing SMLS , HFW , SAW , or COW Each pipe
19 Macrographic testing of the longitudinal or helical seam weld of welded pipe SAW or COW At least once per operating shift plus whenever any change of pipe size occurs during the operating shift ; or , if 10.2.5.3 or 10.2.5.4 applies , at the beginning of the production of each combination of specified outside diameter and specified wall thickness
20 Metallographic testing ( or optional hardness test in lieu of metallography )of the longitudinal seam weld of welded pipe HFW excluding full – body normal At least once per operating shift plus whenever changes of grade , specified outside diameter or specified wall thickness are made ; plus whenever excursions from operating heat treatment conditions are encountered
21 Visual inspection SMLS,HFW,SAW,OR COW Each pipe , except as allowed by 10.2.7.2
22 Pipe diameter and out – of – roundness SMLS,HFW,SAW,OR COW At least once per 4 h per operating shift plus whenever any change of pipe size occurs during the operating shift
23 Wall thickness measurement All pipe Each pipe ( see 10.2.8.5)
24 Other dimensional testing SMLS,HFW,SAW,OR COW Random testing , with the details left to the discretion of the manufacturer
25 Weighing of pipe withD <141.3 mm (5.563 in .) SMLS,HFW,SAW,OR COW Each pipe or each convenient group of pipe , with the choice being at the discretion of the manufacturer
26 Weighing of pipe with D 2141.3 mm (5.563 in .) SMLS,HFW,SAW,OR COW Each pipe
27 Length SMLS,HFW,SAW,OR COW Each length of pipe shall be measured , except that pipe made in lengths that are uniform within 30 mm (0.1 ft ) need not b individually measured , provided the accuracy of the length is verified at least once per 4 h per operating shift
28 Nondestructive inspection SMLS,HFW,SAW,OR COW In accordance with Annex E
a The cold – expansion ratio ( if applicable ) is designated by the manufacturer and is derived using the designated before – expansion outside diameter or circumference and the after – expansion outside diameter or circumference ; an increase or decrease in the cold – expansion ratio of more than 0.002 requires the creation of a new test unit . b Pipe produced by each welding machine shall be tested at least once per week . c For double – seampipe , both longitudinal weld seams in the pipe selected to represent the test unit shall be tested . d Applies only to finished helical seam pipe containing coil / plate end welds . e ” Test unit ” is as defined in 3.1.60.

How to Select an API 5L Certified Line Pipe Supplier in China?

When selecting an API 5L certified supplier in China, it is important to be aware of the fake certificates that some companies use. These fake certificates are often created using photoshop and can be very difficult to identify. However, they can often trick buyers into thinking they are getting a high-quality product when in reality the product is of low quality and may even be dangerous. This damages the projects that use these pipes because they are not up to code and they can cause safety issues. If something goes wrong, the company that chose the line pipe supplier with a fake certificate can be sued and lose a lot of money in compensation payments. Don’t let this happen to your company! As such, it is always best to select a reputable and trustworthy supplier who can provide you quality pipes with a genuine API 5L certificate. This will help to ensure the safety of your business and avoid any potential legal problems. Next, I’ll show you how to spot fake certificates.

1. Check the API Composite List

api 5l piep

The Composite List is a directory of all the companies that are certified by the American Petroleum Institute (API). This list can be used to check if a line pipe manufacturer is authorized to use the API logo on its products. To search the Composite List, 

1) Go to the API official website and find the “API Composite List” tab;

2) You will see the screenshot above, type in the company name or certification number, and click “Search”;

3) Finally, you will see the company detail about the certification types and the certification status. 

If the certification type is what you are looking for, and the certificate status also shows “Active”, then you are safe at this stage. While you may also interested in checking the company details to see if you are dealing with the right person, you can click on the company name shown in red.

2. Check the Non-Licensee / Registrant List

api 5l pipe

The American Petroleum Institute (API) also released a list showing all the cheater companies that API has found in the past, and these companies are still in the market. The API Non-Licensee/Registrant List is a great resource for finding unqualified suppliers who are holding fake certificates. Here is how to check the list:

1) Go to the API official website and find the “Non-Licensee/Registrant List” tab;

2) Scroll down to find all the cheater companies who may want to fool you with a fake license.

You can use this information to help you narrow down your search for a qualified line pipe supplier. If you are looking for a specific company, you can type the company name in the “Search” box.

3. Check the MTC from the Supplier

api 5l pipe

Even if you don’t find anything unusual in the above steps, it doesn’t mean your supplier is qualified. I suggest you check its MTC in the next step. I know an MTC is easy to be “cloned”, but you may still find some weak points in it.

1) The company name – as you can see in the above picture, the name is very similar to our company name, but they are absolutely different. On a real certificate, the “Co.” would never be written as “Company”, and the “Ltd” would never be written as “Limited”.

2) The CNAS certification – CNAS is an organization that evaluates whether a lab can be accredited to National Accredited Testing Laboratory in China. It has bilateral or multi-lateral accreditation cooperation agreements with relevant accreditation organizations around the world. So we can check this certificate also to eliminate our doubts. First, go to the CNAS official website; Second, click on “Find an Accredited Body“; Then, choose “Testing & Calibration Laboratories“, and type in the registration number or the company name; Finally, you can check if the registration number and company name are matched to the MTC you have;

3) The API certification number – Usually, a line pipe mill that is holding the API certification would show the certification numbers on the MTC. While there is none of it on the sample MTC above.

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