Patent ID: 6435022
Filing Date: 2002-08-20
Classification: F16K

Abstract:
A partial stroke testing system for online testing of an emergency shut-off valve, said system implemented on an emergency shut-off valve normally movable between fully opened and fully closed position, said system comprising an emergency shut-off valve, control means for initiating an electrical signal for initiating a test on said emergency shut-off valve, a source of pressurized gas and means including a main solenoid responsive to a signal from said control means, a main solenoid valve and a quick exhaust valve connected to said source of pressurized gas and a pneumatic actuator for opening and closing the said shut-off valve, test means for testing said emergency shut-off valve without fully closing said emergency shut-off valve in response to a signal from said control means, said test means including a second solenoid, a second solenoid valve for bleeding off pressurized gas to thereby move said emergency shut-off valve from full opened position to a partially closed position, means for limiting the movement of said emergency shut-off valve to a partially closed position as a result of the bleeding off of pressurized gas and means for detecting actual movement of said emergency shut-off valve.