Patent ID: 6457697
Filing Date: 2002-10-01
Classification: F16K

Abstract:
A foreign particle resistant electric actuated pilot operated valve assembly comprising:a) a housing having a main fluid cavity with inlet and outlet passages in communication therewith; b) a main valve seat within said housing between said inlet and outlet passages; c) a pressure responsive flexible diaphragm having an enlarged peripheral section and a main valve member disposed in said main fluid cavity, said main valve member movable with respect to said housing from a closed position contacting said valve seat to an open position spaced apart from said seat to permit flow from said inlet to said outlet passage; d) means defining a pilot chamber where pressure responsive flexible diaphragm forms a portion thereof; e) a pilot flow path communicating said inlet passage, said pilot chamber, and said outlet passage, said pilot flow path having a pilot passage and bleed passage therein, said pilot passage and said bleed passage having a pressure drop relationship therebetween, said pressure responsive flexible diaphragm responsive to said pressure drop relationship; f) a cover means having a cavity therein and forming a part of said pilot chamber, said cover means disposed within said main fluid cavity of said housing, said cover means and said main fluid cavity forming a clearance space therebetween, said cover means having a pilot flow bleed passage therein and with said clearance space form a part of said pilot flow path; g) a pilot valve member within said pilot chamber and movable between a closed position preventing pilot flow through said pilot flow passage and an open position permitting pilot valve flow therethrough said pilot member operable upon electromagnetic energization and de-energization to move said pilot valve member to said open and closed positions to effect opening and closing of said main valve member; h) a plurality of channel configurations formed in said main cavity of said housing to form a plurality of screening passages with said enlarged peripheral section of said diaphragm when said enlarged peripheral section is sandwiched between said cover means and said channel configurations, said screening passages forming a part of said pilot flow path and sized to prevent entry of foreign particles that could block said bleed passage and cause malfunction of said valve assembly.