摘要 |
Upper and/or lower seal plates of a sub plate mounted, pilot actuated spool valve are reinforced with one or more metal rings. In a number of preferred embodiments, the metal ring is comprised of steel. Portions of the seal plates may comprise an engineering thermoplastic such as polyoxymethylene (POM) sold by E. I. DuPont de Nemours under the DELRIN® trademark. The plastic material may be molded to the metal ring. In other embodiments, the plastic material and metal ring(s) are mechanically connected together. |