Ring Type Gasket

The rig type gasket can be used for both the RF and FF flanges. It sits around the pipe bore and inside of the flange bolts, and in the RF flange, it is positioned on the raised surface. The ring type gasket is a drop-in gasket, which means it can be installed without taking apart the whole joint. It also requires less material and cutting than a full-face gasket, though it can be harder to clamp into position.

The measurements you need to know for ring type gaskets are the ID (the inside diameter or pipe bore size), the OD (the outside diameter), and the thickness of the gasket.

The Difference Between a Raised Face and Flat Face Flange

The difference between a raised face and a flat face flange is that the raised face has a raised area that surrounds the pipe bore and the flat face flange doesn’t. These are two of the most commonly used types of flange faces. They can both be sealed with one of two different types of gaskets, the ring type and the full-face gasket. This post will provide some details on the raised face flange, the flat face flange, and the two types of gaskets used with them.

Raised Face Flange

The raised face is the most common flange face type used. It’s called a raised face because it has a raised surface above the bolting circle where the gasket is placed. Sealing this type of flange face is accomplished by compressing a soft, flat, or semi-metallic gasket between mating flanges in the raised area of the flanges.

Raised face (RF) flanges are common in process plant applications but can be used in almost all applications. They are suitable for use in high and low temperatures and pressures. The purpose of the RF flange is to focus more pressure on the smaller gasket area, which increases the pressure containment capabilities of the joint.

Flanges are sized according to pressure ratings. The higher the pressure rating of the RF flange, the bigger the flange diameter, the number of bolts it requires, and the thicker both the flange itself and the raised face are.