What is the difference between PSL1 And PSL2 pipes?

An API 5L line pipes manufactured in two varieties PSL 1 and PSL 2. But what is PSL? PSL stands for Product Specification Levels.

Pipes are used in different types of environments such as corrosive and non-corrosive.Pipes used in the severe corrosive environments required material that can withstand such process conditions. On the other hand for normal services, a standard quality level pipe will also serve the purpose.

API 5L PSL1 Grade B seamless steel pipes

API 5L PSL1 Grade B seamless steel pipes

Difference between PSL1 and PSL2 pipes are as follows:

  • Chemical Properties
  • Mechanical Properties
  • Manufacturing Methods
  • Inspection and Defect Repair
  • Certification & Traceability

Chemical Properties:

Parameter PSL1 PSL2
Chemistry: Max C for seamless pipe 0.28% for grades≥B 0.0024
Chemistry: Max C for welded pipe 0.26% for grades≥B 0.0022
Chemistry: Max P 0.03% for grades≥A 0.0003
Chemistry: Max S 0.0003 0.0002
Carbon equivalent Only when purchaser specifies SR18 Maximum required for each grade

Three elements change when requirements change from PSL1 to PSL2.

The first is Carbon.

Maximum Carbon for Seamless PSL1 pipe is 0.28% for grade B & higher. For all grades of PSL2 pipes maximum carbon is 0.24%.

Similarly, for welded PSL1 pipe Maximum Carbon is 0.26% for grade B & higher. For all grades of PSL2 welded pipes maximum carbon is 0.22%.

The second element is Phosphorus.

For PSL1 pipe, Maximum Phosphorus is 0.03% for the grade A & higher. For all grades of PSL2 pipes, the maximum Phosphorus is 0.03%. So, the only difference is a grade lower than A.

The third element is Sulphur.

For PSL1 pipe, Maximum Sulphur is 0.03%. For PSL2 pipes maximum Sulphur is 0.02%.

Other than these three elements, for PSL2 pipe meeting, the Carbon equivalent is mandatory whereas for PSL1 pipe it is only required if the purchaser has specified SR18. SR18 means Supplementary Requirement No.18.

API 5L PSL2 X70 seamless steel pipes

API 5L PSL2 X70 seamless steel pipes

Mechanical Properties:

Parameter PSL1 PSL2
Yield strength,maximum None Maximum for each grade
UTS(Ultimate Tensile Strength) maximum None Maximum for each grade
Fracture toughness None required Required for all grades

For PSL2 pipe there is a limit on Maximum Yield & Ultimate Tensile Strength whereas for PSL1 pipe meeting the minimum requirements are sufficient. The second requirement that is mandatory for PSL2 pipe is Fracture toughness which is not required for the PSL1 pipe.

The difference between PSL1 & PSL2 pipes manufacturing:

Parameter PSL1 PSL2
Grade Range A25 through X70 B through X80
Size Range 0.405″ through 80″ 4.5″ through 80″
Type of ends Plain end,threaded end,bevelled end special coupling pipes Plain end
Seam welding All methods:continuous welding limited to A25 All methods:except continuous welding and laser welding
Electric welds:welder frequency No minimum kHZ minimum 100
Heat treatment of electric welds Required for grades>X42 Required for all grades(B through X80)

Here in this table, you can see the differences between PSL1 & PSL2 Pipes Manufacturing. PLS1 pipes are available in grade A25 through X70 whereas PSL2 pipes are available in Grade B through X80.

PSL1 pipes are available through size 0.405″ to 80″ whereas the smallest diameter pipe available in PSL2 is 4.5″ and the largest diameter is 80″.

As a professional piping supplier,we can supply API 5L PSL1 & PSL2 pipes, A53 electirc resistance steel pipes, A106 seamless steel pipes and so on.If you want to know more about our products,please email to us: sales@haihaogroup.com