Performance and Behavior of Seals for Pneumatic Spool Valves

This article presents a seal development approach that takes actual operating conditions (mounting, sealed pressure, lubri-cating conditions), seal material, and counterpart machining tolerances into account. The approach was applied to the de-sign of seals for a commercial pneumatic spool valve. A single seal geometry and two seat configurations were specified on the basis of finite element analysis and experimental tests. The goal was to develop a compact low-friction seal capable of operat-ing dry in order to avoid the use of grease. The investigation focused on seals that are somewhat shorter (i.e., with a smaller radial height to permit application on new valve models) than existing commercial units but whose performance is not infe-rior. Prototypes of the new seal were manufactured and tested, and a specific device for measuring seal friction force and seal-ing was developed. The existing commercial seal was also in-vestigated. The commercial seal and the proposed new designs were then compared