API 5L X65 line pipe is one of the most cost-effective and safe solutions for transporting oil and natural gas. A significant number of pipeline failures are caused by corrosion, which can lead to structural weakness and potential leaks. Plastic deformation can alter the mechanical properties of the pipe, making it essential to understand how the steel behaves under such conditions to prevent catastrophic failures. The designation API 5L X65 PSL2 refers to a specific grade of line pipe that meets higher performance standards compared to PSL1. This includes stricter chemical composition requirements and mandatory minimum fracture toughness, ensuring better reliability in demanding environments. Vertical Machining Center,Machine Center Cnc,Cnc Vertical Milling Machines,Vertical Milling Machine Cnc Suzhou Loong Won Machinery Technology Co., Ltd. , https://www.loongwon.comAPI 5L X65 Line Pipe Application Range
Delivery Conditions for API 5L X65 Line Pipe
PSL
Delivery Condition
Pipe Grade
PSL1
As-rolled, normalized rolled, thermomechanical rolled, thermo-mechanical formed, normalized formed, normalized, normalized and tempered
X42, X46, X52, X56, X60, X65, X70
PSL2
Quenched and tempered
BQ, X42Q, X46Q, X56Q, X60Q, X65Q, X70Q, X80Q, X90Q, X100Q
Â
Thermomechanical rolled or thermomechanical formed
BM, X42M, X46M, X56M, X60M, X65M, X70M, X80M
Chemical Composition for API 5L X65 PSL1 Pipe (t ≤ 0.984")
Steel Grade
Mass fraction, % based on heat and product analyses a,g
C
Mn
P
S
V
Nb
Ti
max b
max b
max
max
max
max
max
Seamless Pipe
X65
0.28 e
1.40 e
0.3
0.3
f
f
f
Welded Pipe
X65
0.26 e
1.45 e
0.3
0.3
f
f
f
f. Unless otherwise agreed, Nb + V = Ti ≤ 0.15%,
Chemical Composition for API 5L X65 PSL2 Pipe (t ≤ 0.984")
Steel Grade
Mass fraction, % based on heat and product analyses
Carbon Equiv a
C
Si
Mn
P
S
V
Nb
Ti
Other
CE IIW
CE Pcm
max b
max
max b
max
max
max
max
max
max
max
max
Seamless and Welded Pipe
X65Q
0.18f
0.45f
1.70f
0.025
0.015
g
g
g
h,l
0.043
0.25
Welded Pipe
X65M
0.12f
0.45f
1.60f
0.025
0.015
g
g
g
h,l
0.043
0.25
h. Unless otherwise agreed, Cu ≤ 0.50% Ni ≤ 0.50% Cr ≤ 0.50% and Mo ≤ 0.50%,
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 for API 5L X65
Pipe Grade
Tensile Properties – Pipe Body of SMLS and Welded Pipes PSL1
Seam of Welded Pipe
Yield Strength a
Tensile Strength a
Elongation
Tensile Strength b
Rt0,5 PSI Min
Rm PSI Min
(in 2in Af % min)
Rm PSI Min
X65
65,300
77,500
c
77,500
c. The specified minimum elongation, Af, expressed in percent and rounded to the nearest percent, shall be determined using the following equation:
Pipe Grade
Tensile Properties – Pipe Body of SMLS and Welded Pipes PSL2
Seam of Welded Pipe
Yield Strength a
Tensile Strength a
Ratio a,c
Elongation
Tensile Strength d
Rt0,5Â PSI Min
Rm PSI Min
R10,5IRm
(in 2in)
Rm (psi)
Â
Â
Â
Af %
Â
Minimum
Maximum
Minimum
Maximum
Maximum
Minimum
Minimum
X65Q,X65M
65,300
87,000
77,600
110,200
0.93
f
76,600
f. The specified minimum elongation, Af, expressed in percent and rounded to the nearest percent, shall be determined using the following equation:
API 5L X65 line pipe application range
Bend test
No cracks shall occur in any portion of the test piece and no opening of the weld shall occur.
Flattening test
Acceptance criteria for flattening test shall be:
EW pipes D<12.750 in:
X60 with T 500in. There shall be no opening of the weld before the distance between the plates is less than 66% of the original outside diameter. For all grades and wall, 50%.
For pipe with a D/t > 10, there shall be no opening of the weld before the distance between the plates is less than 30% of the original outside diameter.
For other sizes refer to the full API 5L specification.
CVN impact test for PSL2
Many PSL2 pipe sizes and grades require CVN. Seamless pipe is to be tested in the body. Welded pipe is to be tested in the body, pipe weld and heat-affected zone. Refer to the full API 5L specification for the chart of sizes and grades and required absorbed energy values.
Surface
All surfaces have been 100% visually inspected. The surface condition complies with API 5L Annex E.
External surface of pipe shall be coated with a layer of varnish.
NDT
All pipes will be ultrasonic tested on pipe body and pipe end as per API 5L Annex E, Table E.2 and para E.3.3.
Coverage:
longitudinal: 100% of the pipe surface
pipe ends not scanned by automatic ultrasonic system shall be inspected by manual UT or Magnetic Particle Examination.
Hydrostatic test
Test pressure may not exceed 2970 psi in accordance to API 5L requirements
Holding time: minimum 5 seconds
Certification and traceability
All dimensions will be supplied with a 3.2 certificate according to EN 10204, endorsed by recognized and independent inspection agency. Marking shall be in SI units (X65) accordance with API requirements & mill standard.