Performance evaluation of high pressure sleeve seal

Abstract

Sealing problems for reciprocating pumps or intensifiers operating at high pressures (above 100 MPa) may be solved by adopting a closely fitting externally pressurized sleeve. This paper presents an elastohydrodynamic (EHD) analysis for such high pressure sleeve type seals and examines the effects of structural and operational parameters on their high pressure performance characteristics. The effects of pressure on the viscosity and density of the working fluid are also considered in the analysis. The numerical results clearly indicate that the sealing efficiency of high pressure sleeve seals can be enhanced with elastic deformation of both the sleeve and the plunger. The effect of working pressure on the stiffness of the sleeve seal and the induced frictional force are also presented. The study of the effect of eccentricity on the radial stiffness shows that it leads to a large radial force and the plunger is pressed on the sleeve surface, hereby termed ‘hydraulic locking’. This phenomenon results in an increase in frictional forces which is one of the key factors for the limited working life of the seal.