Finite Element Redesign Of Reciprocating ‘PTFE’ Rod Seals

The paper deals with a non-linear Finite Element analysis of the mechanical behaviour of a reciprocating rod seal assembly, composed of a PTFE Edgeseal and of an elastomeric 0-ring. As a first step, a widely spread commercial version of this composite seal is numerically analyzed and the predictions are compared with published experimental data. Next, following the indications of an oversimplified model of the seal, several geometric parameters of the Edge-seal section are tentatively adjusted for improved performance and checked by means of refined Finite Element analyses. In the optimizing process, the linearity of the pressure profile at the rod-seal contact and the delay of seal extrusion at the low-pressure side of the assembly are selected as design objects.