Flange facings Contact surfaces to seat the sealing gasket material. Wide face: Non-standard Simple Gasket extended beyond bolt holes Soft gasket P<20kg/cm2, T<220 C Narrow face

Raised face Most common type Average service conditions Gasket surfaces are raised above the bolting circle face. The raised faces have a prescribed texture to increase their gripping and retaining force on this flat gasket. 

Male and Female Face Flanges must be matched. One flange face has an area that extends beyond the normal flange face (Male). The other flange flange has a matching depression (Female) machined into it's face. The female face is 3/16-inch deep, the male face is 1/4-inch high Heat Exchanger shell to channel and cover flanges.

M & F flange face

Tongue and Groove face Gasket is placed inside the groove They differ from male-and-female in that the inside diameters of the tongue-and-groove do not extend into the flange base, thus retaining the gasket on its inner and outer diameter. These are commonly found on pump covers and Valve Bonnets. Self-aligning

Tongue and Groove face

Ring facing Two identical grooves made in both facings Ring shaped gasket fits into the grooves Severe conditions &/or hazardous fluids

Gaskets Plastic/semiplastic material placed between two flanges & held tight by series of bolts Tries to expand and occupy space between two flange facings, thereby sealing minute irregularities Min force reqd by the gasket to flow and seal the surface is known as Yield or Seating Force Ratio of gasket stress to internal pressure is called Gasket Factor

Requirements for a gasket Good compressibility and face adaptability Good recovery Strength Chemical resistance Temperature resistance

Major Classification