Fundamental Principles for Static Sealing with Metals in the High Pressure Field

Abstract

This paper provides results obtained from extensive investigation of the seal problems for static seals in high pressure equipment. Joints with flat raised faces and profiled tongues vs. flat faces were investigated using various degrees of surface finish, pressure media and face geometries. A safe and reliable seal against liquids and gases under extreme pressures cannot be achieved with tightening forces that produce elastic deformations of the interface areas only, regardless of degree of surface finish. A gas-tight static seal against high internal pressures (gas or liquid) requires plastic deformation of the seal interface areas. With plastic flow of the material, all surface asperity differences are leveled out and the leakage flow passages are completely blocked.