API 5L X80


API 5L X80

API 5L X80 line pipe is a type of pipeline steel used in the transportation of petroleum, oil & gas. This type of pipe is mostly used to transfer fluids, including crude oil, natural gas, and petroleum products, from one site to another. This sort of pipe is often constructed from high-strength steel, which enables it to survive the high pressures and temperatures that are common in these sectors. In addition, API 5L X80 line pipe is typically coated with a layer of corrosion-resistant material, such as FBE, 3LPE, or 3LPP, to protect it from the harsh environment in which it is used.

The American Petroleum Institute API 5L specification is for line pipes used in pipelines for transporting oil, natural gas, and water. The line pipe depicted in the API 5L specifications in this document is intended for use in conjunction with other standards that are currently being developed by the American Petroleum Institute’s Pipeline Transportation Committee.

Why choose tuspipe?


Since 1998, Tianjin United Steel Pipe Co., Ltd (TUSPIPE) has been committed to supplying high-quality line pipes.

With over 500,000 tons annual production capacity, the company serves various fields and industries, such as oil & gas exploitation and transmission, ship & auto-building, water & electricity, environmental protection, mechanical engineering, infrastructure construction and etc.

TUSPIPE places a premium on product quality and rigorous product quality control. In order to maintain good product quality,  the company has established a Test & Inspection Center since 2004. With a series of state-of-the-art tests and inspection equipment, the test & inspection center is able to perform the tensile tests, hydro tests, impact tests, DWTT, etc.

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Application of API 5L X80 Line Pipe

API 5L X80 line pipe is a commonly used pipeline in the petroleum and oil and gas industries. Its versatile applications make it an essential part of the transport and supply of these materials. The main advantage of using API 5L X80 line pipe is its high strength. This allows it to transport large volumes of petroleum and oil without fear of rupturing or leaking. Additionally, its resistance to corrosion means that it can be used in a wide range of environments without fear of degradation. As a result, API 5L X80 line pipe is an essential component of the petroleum and oil and gas industries, and its applications are varied and essential.

Equivalent Steel Grade of X80 Material

Steel GradeEquivalent Grade
X80 PSL-1
X80 PSL-2L555Q or X80Q
L555M or X80M

Chemical Composition of API 5L X80 Pipe with t ≤ 0.984”

Steel GradeMass fraction, % based on heat and product analysesCarbon Equiv a
max bmaxmax bmaxmaxmaxmaxmaxmaxmax
Welded Pipe

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%.

API 5L X80 Pipe Mechanical Properties

Pipe GradeTensile Properties – Pipe Body of SMLS and Welded Pipes PSL 2Seam of Welded Pipe
Yield Strength aTensile Strength aRatio a, cElongationTensile Strength d
Rt0,5  PSI MinRm  PSI MinR10,5IRm(in 2in)Rm (psi)
Af %
X80Q, X80M80,500102,30090,600119,7000.93f90,600
a. For intermediate grade, refer to the full API5L specification.
b. for grades > X90 refer to the full API5L specification.
c. This limit applies for pies with D> 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 foot a.
e. for pipe requiring longitudinal testing, the maximum yield strength shall be ≤ 71,800 psi
f. The specified minimum elongation, Af, expressed in percent and rounded to the nearest percent, shall be determined using the following equation:
Where C is 1 940 for calculation using Si units and 625 000 for calculation 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, 130mm2 (0.20 in2) for 12.7 mm (0.500 in) and 8.9 mm (.350 in) diameter test pieces; and 65 mm2 (0.10 in2) for 6.4 mm (0.250in) 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 (0.10in2)
–  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 (0.10in2)
   U is the specified minimum tensile strength, expressed in megapascals (pounds per square inch
g. Lower values fo R10,5IRm may be specified by agreement
h. for grades > x90 refer to the full API5L specification.

Dimensions and Sizes of API 5L X80 Line Pipe

Before purchasing an API 5L X80 line pipe, it is important to check the size and dimensions of the pipe to ensure that it meets the required standards. The dimensions and masses of API 5L line pipes are specified in ISO 4200 and ASME B36.10M. These standards provide a guide for different size 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 pipe is the right diameter and has the correct wall thickness. This is essential in order to meet the requirements for use in different applications. Purchasing a pipe that does not meet the required standards can result in problems during installation or use, so it is important to be aware of the correct dimensions and tolerances before making a purchase.


API 5L X80 Pipe Tolerance

O.D. ToleranceW.T. Tolerance
D < 60.3mm+0.41/-0.40mmD < 73mm+15%/-12.5%
D ≥ 60.3m+0.75/-0.40mmD ≥ 73mm+15%/-12.5%

Test and inspection of API 5L X80 Line pipes

- Hydrostatic Test

The hydrostatic test is performed during the production of the API 5L line pipe. The purpose of the test is to check for leaks in the weld seam or the pipe body. water is used as the testing medium, and the water pressure is increased until it reaches the specified value. If there are no leaks, the test is successful. If a leak is detected, the pipe is repaired and the test is repeated. The hydrostatic test is a critical step in the production of API 5L line pipe, and it helps to ensure that the finished product is safe and reliable.

- Bend Test

The bending test is an important quality control check during the production of the API 5L line pipe. The test involves taking a sample of the steel pipe and applying a force to it until it cracks. This helps to ensure that the pipe will not crack under stress during service. The bend test is typically carried out on welded samples, as this is where most failures occur. However, it is also important to test unwelded samples to ensure that the material is of good quality. The results of the bend test are used to adjust the manufacturing process to ensure that the final product meets the required standards.

- Flattening Test

The flattening test is one of the essential mechanical tests performed on steel pipes during their manufacture. It helps to ensure the quality of the finished product and prevent any cracks or other defects that could cause problems later on. The test is carried out by taking a sample of the pipe and applying a force to it until it deforms. The amount of deformation is then measured, and this provides an indication of the pipe’s strength and resistance to cracking. The flattening test is an important part of the manufacturing process for steel pipes and is essential for ensuring their quality and safety.

- CVN Impact Test

Any company that wants to produce API 5L line pipe must first submit their product to an impact test. Three areas will be tested: the pipe body, weld seam, and heat-affected zone. The purpose of the impact test is to ensure that the line pipe can withstand sudden changes in temperature and pressure without shattering or breaking. If any of the three areas fail the impact test, the line pipe will not be certified and cannot be sold. The impact test is just one of many tests that a line pipe must go through before it can be certified by the API.

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