Patent ID: 8539973
Filing Date: 2013-09-24
Classification: F16K,Y10T

Abstract:
1. A method of converting a normally closed electric solenoid valve to a non-electrically operated normally open valve, comprising providing said solenoid valve including a flow path through a valve seat, a housing extending from said valve seat, and a plunger normally spring-biased into valve-closing contact with said valve seat but retractable into a cavity in said housing by energizing a solenoid coil to open said valve, and comprising the steps of: a) removing said spring-biased plunger; b) modifying said housing to allow the selective introduction of a pressure medium into said cavity; c) sealing closing off said cavity from said flow path with a diaphragm sufficiently flexible to normally be pushed off said valve seat by the pressure of a fluid flowing in said flow path; and d) selectively introducing a pressure medium into said cavity so as to bias said diaphragm into contact with said valve seat when it is desired to close the valve.