Cross-system equivalents
Cross-system grades are nearest counterparts, not drop-in substitutes. Chemistry and mechanical envelopes overlap but are not identical — where a design code names a grade, order that grade. Final selection should be confirmed by your project engineer against the governing code.
| Standard system | Grade designation |
|---|---|
| ASME / ASTM | API 5L Gr.B / X42 – X70 · A106 Gr.B |
| EN / DIN | L245 – L485 (EN 10208) |
| JIS | STPG370 / STPG410 |
| GOST | Ст20 / 09Г2С |
| GB | L245 – L485 (GB/T 9711) |
Where this grade belongs
- Oil and gas gathering, transmission and distribution lines
- Refinery and petrochemical process piping (A106 Gr.B)
- Wellhead and flowline service
- Structural and general pressure applications
Where it does not
The failures we see most often are not bad material — they are the right material in the wrong service.
- Ordering PSL1 where PSL2 is specified — The grades look similar on paper but PSL2 carries mandatory impact testing and tighter chemistry limits. Substitution will fail document review.
- Sour service without qualification — Sour gathering lines require NACE MR0175 / ISO 15156 compliance with HIC and SSC testing — this must be specified at order, not assumed.
- Low-temperature service without impact data — Standard grades carry no low-temperature qualification. Specify the test temperature required.
What we supply in API 5L
Forms: Seamless and welded pipe; matched butt-weld fittings in A234 WPB and flanges in A105
Size range: DN6 – DN3000 (1/8" – 120"), Sch 10 through Sch 160 / XXS
Documentation available
- EN 10204 3.1 material test certificate traceable to the heat number
- API 5L PSL2 where specified
- NACE MR0175 / ISO 15156 with HIC and SSC testing for sour service
- Hydrostatic test and non-destructive examination records
- Third-party inspection by SGS, BV or TÜV welcome at any stage
Frequently asked
What is the difference between API 5L PSL1 and PSL2?
PSL2 adds mandatory Charpy impact testing, tighter chemistry and carbon equivalent limits, and stricter documentation requirements. Most project specifications call for PSL2; the two are not interchangeable at document review.
What is the difference between API 5L Gr.B and A106 Gr.B?
API 5L Gr.B is line pipe for hydrocarbon transmission; A106 Gr.B is seamless pipe for high-temperature process service. Chemistry overlaps considerably and dual certification is common, but the governing standard differs.
What does X52 or X65 mean?
The number is the specified minimum yield strength in thousands of psi — X65 means 65,000 psi SMYS. Higher grades allow thinner wall for the same pressure, which is why transmission lines use them.
Related grades
- ASTM A234 WPB — Carbon steel butt-weld fittings
- ASTM A105 — Carbon steel forgings — flanges and forged fittings
- Duplex S31803 / S32205 & Super Duplex S32750 — Duplex and super duplex stainless steel
Full cross-reference across all families: Technical Guide § 2 — Material Grade Equivalents. Pressure class and schedule conversion: § 3 — Pressure Ratings & Pipe Schedules.