Patent ID: 9732878
Date: 2017-08-15
CPC Classifications: F15B,F16K

Claim:
1. A partial stroke testing system for testing an emergency shut-off valve that is normally movable between fully opened and fully closed positions, said system consisting of: an emergency shut-off valve, means for initiating a test on said emergency shut-off valve, a source of pressurized gas, a main solenoid and means including said main solenoid responsive to a signal from said means for initiating a test on said emergency shut-off valve, and means including a main solenoid responsive to a signal from said means for initiating a test, said main solenoid valve and a quick exhaust valve connected to said source of pressurized gas, and a pneumatic actuator for opening and closing 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 means for initiating a test, 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 a fully opened position to a partially closed position and wherein said test is based on the theory of pneumatic equilibrium.