The API 5L standard covers seamless steel pipes and welded steel pipes (such as high-frequency welded ERW, submerged arc welded LSAW, etc.). According to the strength level, it can be divided into two product specification levels: PSL1 and PSL2. PSL1 is the basic level and is suitable for general transportation scenarios. PSL2 has stricter requirements for chemical composition, toughness, non-destructive testing, etc., and is suitable for high-pressure, corrosive environments or high-risk areas. Common strength levels include B, X42, X46, X52, X56, X60, X65, X70, X80, etc. The numbers represent the minimum yield strength (unit: thousand pounds per square inch, ksi). For example, the minimum yield strength of X52 is 52 ksi (approximately 358 MPa).
API 5L Grade and chemical composition
| Standard | Product Category | Grade | Chemical Composition(%) |
|---|---|---|---|
| API 5L GB/T9711.2 | PSL 1 | A or L210 | C ≤0.22,Mn ≤0.90,P ≤0.030,S ≤0.030,Ceq ≤0.25 |
| API 5L GB/T9711.2 | PSL 1 | B or L245 | C ≤0.28,Mn ≤1.20,P ≤0.030,S ≤0.030,Ceq ≤0.25 |
| API 5L GB/T9711.2 | PSL 1 | X42 or L290 | C ≤0.28,Mn ≤1.30,P ≤0.030,S ≤0.030,Ceq ≤0.25 |
| API 5L GB/T9711.2 | PSL 1 | X46 or L320 | C ≤0.28,Mn ≤1.40,P ≤0.030,S ≤0.030,Ceq ≤0.25 |
| API 5L GB/T9711.2 | PSL 1 | X52 or L360 | C ≤0.28,Mn ≤1.40,P ≤0.030,S ≤0.030,Ceq ≤0.25 |
| API 5L GB/T9711.2 | PSL 1 | X56 or L390 | C ≤0.28,Mn ≤1.40,P ≤0.030,S ≤0.030,Ceq ≤0.25 |
| API 5L GB/T9711.2 | PSL 1 | X60 or L415 | C ≤0.28,Mn ≤1.40,P ≤0.030,S ≤0.030,Ceq ≤0.25 |
| Product Category | Grade | C(%) | Mn(%) | P(%) | S(%) | Cr(%) | Ni(%) | Cu(%) | V(%) | CEpcm |
|---|---|---|---|---|---|---|---|---|---|---|
| PSL 2 | X42R or L245R | ≤0.24 | ≤1.20 | ≤0.025 | ≤0.015 | ≤0.40 | c | c | ≤0.04 | ≤0.25 |
| PSL 2 | X42R or L290R | ≤0.24 | ≤1.20 | ≤0.025 | ≤0.015 | ≤0.40 | ≤0.06 | ≤0.05 | ≤0.04 | ≤0.25 |
| PSL 2 | X42N or L245N | ≤0.24 | ≤1.20 | ≤0.025 | ≤0.015 | ≤0.40 | c | c | ≤0.04 | ≤0.25 |
| PSL 2 | X42N or L290N | ≤0.24 | ≤1.20 | ≤0.025 | ≤0.015 | ≤0.40 | ≤0.06 | ≤0.05 | ≤0.04 | ≤0.25 |
| PSL 2 | X46N or L320N | ≤0.24 | ≤1.40 | ≤0.025 | ≤0.015 | ≤0.40 | ≤0.07 | ≤0.05 | ≤0.04 | ≤0.25 |
| PSL 2 | X52N or L360N | ≤0.24 | ≤1.40 | ≤0.025 | ≤0.015 | ≤0.45 | ≤0.10 | ≤0.05 | ≤0.04 | ≤0.25 |
| PSL 2 | X56N or L390N | ≤0.24 | ≤1.40 | ≤0.025 | ≤0.015 | ≤0.45 | ≤0.10 | ≤0.05 | ≤0.04 | ≤0.25 |
| PSL 2 | X60N or L415N | ≤0.24 | ≤1.40 | ≤0.025 | ≤0.015 | ≤0.45 | ≤0.10 | ≤0.05 | ≤0.04 | Negotiation |
Cr：Unless otherwise agreed, the sum of V and Nb should be ≤0.06%.
API 5L pipes, with their high strength, pressure resistance, and corrosion resistance, are widely used in the following fields:
Oil and gas transportation: Onshore and subsea oil and gas gathering and transportation pipelines, long-distance transmission trunk lines;
Chemical industry: Transportation of corrosive media (such as acidic gases and chemicals);
City gas: Medium and low-pressure pipelines in city gas networks;
Energy projects: High-temperature and high-pressure pipeline systems such as LNG receiving terminals and oil refineries.
