API 5L pipes can be divided into two grades:PSL1 and PSL2.PSL is short for Product Specification Levels.Both levels of API 5L line pipes contain seamless steel pipe and welded steel pipe and used of a pipeline in the transportation of petroleum and natural gas.In API 5L specification,what are the differences between API 5L PSL1 pipes and API 5L PSL2 pipes?
API 5L PSL1 Grade B seamless steel pipes
The difference between API 5L PSL1 pipes and API 5L PSL2 pipes-chemical composition
API 5L PSL1 steel line pipes and API 5L PSL2 steel line pipes have different steel grade,and three elements change when requirements change from PSL1 to PSL2.
- First element is Carbon.
The maximum carbon content of API 5L PSL1 seamless steel pipe is 0.28% for the grade B & higher. For all grades of API 5L PSL2 steel pipes maximum carbon is 0.24%.
Similarly,for API 5L PSL1 welded pipe the maximum carbon is 0.26% for the grade B & higher.For all grades of API 5L PSL2 welded pipes the maximum carbon content is 0.22%. - The second element is Phosphorus.
For API 5L PSL1 pipe,the maximum phosphorus content in grade A & higher is 0.03%.For all grades of API 5L PSL2 steel pipes,the maximum phosphorus is 0.025%.So,the only difference is PSL2 grade lower than PSL1 grade. - The third element is Sulphur.
For API 5L PSL1 steel pipes,the maximum sulphur content is 0.03%.For API 5L PSL2 steel pipes,the maximum sulphur content is 0.015%.
If you want to know the detail specification of API 5L PSL1 and PSL2 steel pipes chemical composition,please read the article:
Chemical composition of API 5L PSL1 and PSL2 steel pipe
The difference between API 5L PSL1 pipes and API 5L PSL2 pipes-mechanical properties
| PARAMETER | API 5L PSL1 | API 5L 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 API 5L PSL2 steel pipe,the maximum yield and ultimate tensile strength are limited;while for API 5L PSL1 steel pipe,it is sufficient to meet the minimum requirements.The second requirement that is mandatory for API 5L PSL2 steel line pipe is Fracture toughness which is not required for the API 5L PSL1 steel line pipe.
If you want to know the detail specification of API 5L PSL1 and PSL2 steel pipes mechanical properties,please read the article:
Mechanical properties of API 5L PSL1 and PSL2 steel pipe
The difference between API 5L PSL1 pipes and API 5L PSL2 pipes-manufacture
| PARAMETER | API 5L PSL1 | aPI 5L 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,bevel 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) |
In this table,you can see the differences between API 5L PSL1 and PSL2 steel line pipes manufacturing process.API 5L PLS1 steel line pipes are available in grade A25 through X70 whereas API 5L PSL2 steel line pipes are available in Grade B through X80.
API 5L PLS1 steel line pipe sizes range from 0.405 ” to 80″,while API 5L PSL2 steel line pipe has a minimum diameter of 4.5 “and maximum diameter of 80”.
API 5L PSL1 steel line pipe has different types of ends,such as plain end,threaded end,bevel end and special coupling pipe,while API 5L PSL2 steel line pipe has only plain end.
API 5L PSL1 steel pipes can be produced by various welding methods.However, continuous welding is limited to Grade A25.For API 5L PSL2 welded pipe,all welding methods except continuous welding and laser welding are acceptable.
For electric weld welder frequency for PSL2 pipe is minimum 100kHz whereas the API 5L PSL1 steel line pipe has no such limitation.Heat treatment of electric welds is required for all Grades of PSL2 pipes,while for API 5L PSL1 steel pipe is required for grades higher than X42.
API 5L PSL2 X70 seamless steel pipes
The difference between API 5L PSL1 pipes and API 5L PSL2 pipes-inspection and defect repair
| PARAMETER | API 5L PSL1 | API 5L PSL2 |
|---|---|---|
| Non-destructive inspection of Seamless | Only when purchaser specifies SR4 | SR4 mandatory |
| Repair by welding of pipe body plate, and skelp | Permitted | Prohibited |
| Repair by welding of weld seams without filler metal | Permitted by agreement | Prohibited |
Non-destructive inspection of a seamless pipe is mandatory for PSL2 pipe whereas for PLS1 pipe it is supplementary requirements.
API 5L Steel Pipes Finished in Haihao Group
The difference between API 5L PSL1 pipes and API 5L PSL2 pipes-certification & traceability
| PARAMETER | PSL1 | PSL2 |
|---|---|---|
| Certification | Traceable only until all tests are passed | Certificates (SR15.1) mandatory |
| Traceability | Traceable only until all tests are passed unless SR15 is specified | Traceable after completion of tests (SR15.2) mandatory |
For PSL1 pipelines,traceability and certification are not required after all required tests have been passed;whereas for PSL2 pipelines, traceability and certification are mandatory.
This is all the difference between API 5L PSL1 and PSL2 steel pipes.
In short,API 5L PSL1 pipes are standard quality pipe for normal services and API 5L PSL2 pipes are higher quality pipe than PSL1.PSL 1 is a loose standard quality for line pipe,whereas PSL 2 contains additional testing requirement, stricter chemical physicals,along with different ceiling limits of mechanical properties, and require Charpy impact testing conditions.
Haihao Group is a professional sales of semeless steel pipe,ERW,SSAW,LSAW hot dipped galvanized steel pipe,we have API 5L certificate.And if you want to learn more about us,please email us:sales@haihaogroup.com
