Flanges - API vs. ASME/ANSI

Sponsored Links

Although the dimensions of ASME and API flanges sometimes are compatible for bolting - they do not share the same pressure rating system.

• ASME rates the pressure of a class based on the material of construction and the design temperature
• API specifies allowable materials and gives it a specific pressure rating

The difference between ASME/ANSI and API is the fabrication material and a higher rated API operating pressure.

ASME/ANSI flanges are commonly used in industrial process systems handling water, steam, air and gas. API flanges are manufactured for high strength operating refinery systems with products such as oil and explosive gases.

The flange standards API 6A and ASME/ANSI B16.5 are similar dimensionally - but the API 6A flanges are rated for higher pressures as indicated below:

¹⁾ In the old API standard, flanges ranged from 1 1/2 to 10(20) inches.

Sponsored Links

Related Topics

• Codes and Standards - Piping codes and standards - ASME, ANSI, ASTM, AGA, API, AWWA, BS, ISO, DIN and more..
• Dimensions - Sizes and dimensions of pipes and tubes, and their fittings - inside and outside diameter, weight and more

Related Documents

• API - American Petroleum Institute - The American Petroleum Institute - API
• Carbon and Stainless Steel Flanges - ASME/ANSI Class 1500 - ASME/ANSI B16.5-1996 Pipe Flanges and Flanged Fittings - Class 1500 Flanges - outside and inside diameters, bolt circles, numbers and diameters of bolts
• Gasket Characteristics - Gaskets are used to make a fluid or gas resistant seal between two surfaces