Forged Carbon Steel Raised Face Blind Flange - China Suppliers & Factory | ASME B16.5 Standards

ASTM A105 is the standard specification for carbon steel forgings for piping applications, while A105N indicates the material has been normalized — a heat treatment process that refines grain structure and improves mechanical properties, making it suitable for more demanding service conditions.

Stainless steel flanges such as ASTM A182 F304/316 are preferred in corrosive environments, high-temperature applications, or where hygiene is critical (e.g., food, pharmaceutical, or chemical industries). Carbon steel is typically used in general-purpose, lower-cost applications where corrosion is not a major concern.

ASTM A182 F51 (Duplex 2205) and F53 (Super Duplex 2507) offer significantly higher strength and superior resistance to stress corrosion cracking and pitting compared to standard austenitic stainless steels. They are widely used in offshore, marine, and chemical processing applications.

Alloy steel flanges under ASTM A182 — including F11 (1.25Cr-0.5Mo), F22 (2.25Cr-1Mo), and F91 (9Cr-1Mo-V) — are designed for high-temperature and high-pressure service, commonly found in power generation, petrochemical, and refinery piping systems.

RF (Raised Face) is the most common type, concentrating bolt load on a smaller gasket area for a reliable seal. FF (Flat Face) uses the full flange face and is typically paired with flat-face equipment like cast iron flanges. FTJ (Full-Face Tongue and Groove Joint) provides a self-aligning, high-integrity seal ideal for critical or high-pressure applications.

Material selection depends on several key factors: operating temperature and pressure, the type of media being transported (corrosive, abrasive, or neutral), industry standards and codes (such as ASME, API), and cost considerations. Consulting with a qualified engineer and referencing relevant ASTM standards is strongly recommended for critical applications.