ASTM B564 UNS N04400 Weld Neck Flange Monel 400 WNRTJ Flange Ring Type Joint Flanges

When to choose Monel 400 / UNS N04400 material

Choose Monel 400 when you need a nickel-copper alloy with excellent corrosion resistance and good strength in aggressive environments where carbon steel, stainless steel (304/316), or even some duplex grades may fail.

Choose RTJ (Ring Type Joint) instead of FF/RF when:

• High pressure
  Typically Class 900, 1500, 2500, and often critical Class 600 service.

• High temperature
  Where soft or spiral-wound gaskets may creep, degrade, or lose sealing force. RTJ metal ring gaskets are more reliable at elevated temperatures.

• Hazardous, toxic, or flammable fluids
  Hydrogen, sour gas, high-pressure steam, hydrocarbons, ammonia, and other services where leakage is unacceptable.

• High cyclic loading, vibration, or thermal cycling
  The confined metal ring gasket resists blowout and creep better than soft gaskets.

• Fire-safe requirements
  Metal ring gaskets perform better in fire conditions than many soft gaskets.

• Offshore, subsea, wellhead, and API 6A equipment
  RTJ is standard for many high-pressure oil and gas applications.

• Space and weight savings at high pressure
  For high classes, RTJ flanges can be more compact than RF flanges.