Patent ID: 6986498
Filing Date: 2006-01-17
Classification: F16K,F25B,Y02B

Abstract:
1. A pilot-operated differential pressure valve for controlling a flow rate of fluid such that a differential pressure of the fluid between an inlet and an outlet for the fluid becomes equal to a differential pressure set by a value of an electric current caused to flow through a solenoid, the differential pressure valve comprising: a main valve having a main valve element arranged in a manner opposed to a main valve seat formed in a passage between the inlet and the outlet, from an upstream side of said main valve; a piston integrally formed with said main valve element to define a first chamber between said piston and said main valve seat, said first chamber communicating with said inlet, said piston having a restricted passage for communicating between said first chamber and a second chamber formed on an opposite side of said piston of said first chamber; and a pilot valve having a pilot valve element arranged in a manner opposed to a pilot valve seat from a downstream side, said pilot valve arranged between said second chamber and a third chamber in communication with said outlet, for controlling a pressure in said second chamber.