Pipe flanges for oil and gas applications span the most demanding combinations of pressure, temperature, and corrosive media in industrial service. From sour-service wellheads (NACE MR0175, ≤22 HRC) to offshore platform injection manifolds, from refinery hydrocracker reactors to LNG receiving terminal vaporizers, the flange spec varies by sub-segment. This page catalogs what we supply for oil & gas and how we ensure compliance with the standards your inspector will check.
| Application | Specification |
|---|---|
| Wellhead Christmas Tree (sour) | ASME B16.5 Class 1500, A350 LF2, NACE MR0175 ≤22 HRC, RTJ facing |
| Offshore Platform Injection Manifold | ASME B16.5 Class 600, F51 duplex, NACE MR0175, RTJ |
| Refinery Hydrocracker Reactor | ASME B16.5 Class 600, A182 F22 (Cr-Mo), 540°C service |
| LNG Receiving Terminal Vaporizer | ASME B16.5 Class 300, F304/L, -162°C cryogenic |
| Subsea Manifold (water depth 1500m+) | ASME B16.5 Class 600, F55 super duplex, FAT-tested |
| Pipeline Pump Station Discharge | ASME B16.5 Class 300, A105, RF facing, MTC 3.1 |
A350 LF2 (low-temperature carbon steel) is the workhorse — low sulfur, low phosphorus, and hardness ≤ 22 HRC per NACE MR0175. For higher-alloy requirements: F22 (Cr-Mo), F51 duplex, or F55 super duplex depending on chloride / H₂S concentration. We supply full MTC 3.1 with per-heat chemical composition and hardness test reports.
We supply API 6A monogram-licensed wellhead and christmas tree flanges for Class 3000-15000 psi working pressure. Materials include AISI 4130 low-alloy steel and F22 (normalized & tempered). Each flange ships with full traceability documentation. Lead time is typically 8-12 weeks for API 6A orders.
ASME B16.5 covers NPS ½ through NPS 24 (Class 150-2500). ASME B16.47 covers NPS 26 through NPS 60 in two series: Series A (MSS SP-44) and Series B (API 605). For pipeline and refinery piping ≥ NPS 26, B16.47 is the standard. Our mill produces both, and we keep B16.47 Series A/B blanks in stock for Class 150-600.
Yes. For offshore orders we routinely host SGS / BV / DNV / LR inspectors at our Cangzhou mill. Witnessed tests include dimensional check, hydrostatic test (typically 1.5x design pressure for 30 min), hardness survey (Brinell per ASTM E10), PMI (positive material identification), and NDE (magnetic particle or dye penetrant on weld repairs). Inspection costs are quoted separately — typically 1.5-3% of order value.
Quick contact options for sourcing pipe flanges (ASME B16.5 / EN 1092-1 / JIS B2220 / BS 4504 / HG/T 20592) with full material traceability and shipping to 60+ countries.