Two separate audiences ask about these grades for good reason — they serve different purposes in Aramco projects. API 5L is for pipeline service; ASTM A106 is for process piping. Both are carbon steel, but specifying the wrong one can cause quality rejections and project delays.
| Property | API 5L Grade B | ASTM A106 Grade B |
|---|---|---|
| Governing Standard | API 5L (Line Pipe) | ASTM A106 (High-Temp Service) |
| Primary Service | Pipelines (cross-country/gathering) | Process piping in plants |
| Manufacturing | Seamless or welded | Seamless only |
| Min. Yield Strength | 241 MPa (35,000 psi) | 241 MPa (35,000 psi) |
| Min. Tensile Strength | 414 MPa (60,000 psi) | 414 MPa (60,000 psi) |
| Carbon Content (Max.) | 0.28% (PSL1) / 0.24% (PSL2) | 0.30% |
| Temperature Range | -29°C to +65°C (pipeline burial) | -29°C to 538°C (process service) |
| Applicable Design Code | ASME B31.4 / B31.8 / B31.12 | ASME B31.3 |
| Aramco Standard | SAES-L-100, SAES-L-108 | SAES-L-105, SAES-L-350 |
| Available in PSL2? | Yes (Aramco often mandates PSL2) | No (single quality level) |
| Hydrostatic Test | Yes (mill) | Yes (mill) |
| Charpy Impact Testing | PSL2 mandatory; PSL1 optional | Not mandatory (unless specified) |
SAEP-347 Annex 4 piping for Saudi Aramco projects is built from four primary carbon steel grades, each covering a distinct product form. ASTM A106 Grade B seamless pipe (SAEP-347 P-001) is the standard plant piping material for process service from -29°C to 427°C, specified under SAES-L-108. ASTM A234 WPB covers butt-weld fittings — elbows, tees, and reducers to ASME B16.9 — assigned SAEP-347 fitting number F-025. ASTM A105N (normalized) governs forged carbon steel flanges to ASME B16.5 and socket-weld or threaded fittings in Class 150 through Class 2500; its SAEP-347 flange number is FL-001. ASTM A516 Grade 70 is the carbon steel plate material for pressure vessels and heat exchanger shells operating to 260°C, commonly appearing in Aramco plant BOMs alongside piping materials. All four grades require EN 10204 Type 3.1 mill test certificates with full chemical and mechanical test data, heat number identification, and the applicable SAEP-347 material number declared on the certificate.
The "X" grades in API 5L refer to higher-strength line pipe grades where the number indicates the minimum specified yield strength in thousands of pounds per square inch (ksi). X42 means 42,000 psi (290 MPa) minimum yield; X65 means 65,000 psi (448 MPa) minimum yield.
API 5L Grade B (non-X) is the baseline grade — minimum yield 35,000 psi (241 MPa). It is the most commonly stocked grade in Saudi Arabia and is interchangeable with ASTM A53 Grade B for many non-Aramco applications, though Aramco projects explicitly require API 5L compliance, not A53.
For Saudi Aramco pipeline projects, SAES-L-108 specifies which API 5L grade and product specification level (PSL1 or PSL2) applies based on design pressure, fluid type, and pipeline category. Aramco frequently mandates PSL2 for its enhanced chemistry controls and mandatory Charpy impact testing.
| Grade | Min. Yield | Min. UTS | Typical Use |
|---|---|---|---|
| Grade B | 241 | 414 | General line pipe |
| X42 | 290 | 414 | Medium-pressure gathering |
| X52 | 358 | 455 | High-pressure lines |
| X60 | 414 | 517 | Large diameter trunk |
| X65 | 448 | 531 | Gas transmission |
| X70 | 482 | 565 | High-capacity gas |
API 5L defines two Product Specification Levels: PSL 1 is the base standard covering dimensional, chemical, and mechanical requirements. PSL 2 adds stricter chemistry limits (lower carbon and carbon equivalent), mandatory Charpy V-notch impact testing, a fracture toughness requirement, and tighter weld seam testing for ERW and LSAW pipe. Saudi Aramco SAES-L-108 mandates PSL 2 for all offshore and sour-service applications, and Aramco engineering typically requires PSL 2 for any pipeline project involving H₂S or CO₂. When in doubt on Aramco projects, specify PSL 2 — PSL 1 pipe will be rejected at inspection if the engineering datasheet calls for PSL 2.
SAEP-347 Annex 4 includes both API 5L and ASTM A106 pipe material numbers among its 12 metallic pipe entries. When sourcing replacement pipe from a stockist for an Aramco project, confirm whether the original specification calls for API 5L (pipeline service) or A106 (process piping) — the two standards are not interchangeable without engineering review and Aramco approval, despite having similar mechanical properties at Grade B level.
Carbon steel grade selection for Saudi Aramco piping systems follows SAES-L-100 (process piping material) and SAES-L-101 (pressure piping for utility systems). For standard process hydrocarbon service, ASTM A106 Grade B seamless pipe is the default SAEP-347 Annex 4 specification. For low-temperature service below minus 29°C, A333 Grade 6 (impact-tested to minus 50°C) is required. For high-temperature service above 425°C, alloy steel A335 Grade P11 (1.25% Cr, 0.5% Mo) or P22 (2.25% Cr, 1% Mo) is specified in SAEP-347 Annex 4 for reformer and fired-heater piping at Saudi Aramco refineries. Pressure vessel shell plate for ASME Section VIII Saudi Aramco vessels is specified as SA-516 Grade 70 (normalised) for service up to 455°C; SA-537 Class 1 for low-temperature service. Gulf Union Ozone cross-references all carbon steel grades to SAEP-347 Annex 4 material numbers on quotations.
Seamless carbon steel pipe for process service. NPS ½" to NPS 24". Schedule 40, 80, 160, XXS.
Seamless and ERW line pipe for gathering and pipeline service. NPS 2" to NPS 16" common stock sizes.
Higher-strength line pipe grades for medium and high-pressure gathering systems. Seamless and welded.
Seamless and welded (ERW) black steel pipe for general utility service. Not for process piping on Aramco projects without engineering approval.
Tell us: API 5L or ASTM A106, grade, NPS size, schedule/wall thickness, length, and quantity. We will confirm stock and pricing within 4 business hours and can ship same day for in-stock items.
Gulf Union Ozone carbon steel grades reference service guides all Saudi Aramco engineering and procurement teams. From standard ASTM A106 Gr B process piping through P11 and P22 alloy chrome-moly for high-temperature reformer service, Gulf Union Ozone supplies the full range with EN 10204 3.1 mill test certificates and heat traceability. Common stocked grades for Saudi Aramco MRO: A106 Gr B seamless pipe (Sch 40, 80, 160, XXS), A105 carbon steel flanges and fittings forgings, A216 WCB valves and pump casings, A234 WPB butt-weld fittings, SA-516-70 pressure vessel plate. Emergency supply of carbon steel plate, pipe, and forging stock is available from the Jeddah warehouse: 48–72 hours to Jubail and Dammam; 72–96 hours to Riyadh; Jeddah same-day collection. EN 10204 3.1 certification from approved mills is provided on all pressure-retaining components.