What is Pressure-sensing trip valves?
Pressure-sensing trip valves are for control applications where a specific valve/actuator action is required when supply pressure fails below a specific point.
The trip valve allows the actuator to fail in an up situation, lock in the last place, or fail in the down position when the supply pressure drops below the trip point. The trip valve resets automatically when the supply pressure increases above the trip point, enabling the system to return to ordinary operation.
Working and Connection of pressure trip valve:
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Trip valve port A must receive the operating pressure that is intended for the top of the actuator cylinder. Depending on the actuator type and accessories being used, this operating pressure will be from a valve positioner or switching solenoid.
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Trip valve port B must provide the top of the actuator cylinder with working pressure. This port should be connected to the manifold assembly at the top of the cylinder or to the cylinder connection on the hydraulic snubber (if one is used) depending on the actuator type and accessories used.
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Trip valve port C shall provide a fail-mode outlet to or from the top of the actuator cylinder for the working pressure. This port should be linked to the volume tank for the fail-down mode. This port should vent to air for the fail-up mode. This port should be plugged into the lock-in-last-position mode.
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Trip valve port D must obtain the working pressure for the actuator cylinder underside. This working pressure will be from a valve positioner or solenoid switch, depending on the type of actuator and the accessories used.
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Trip valve port E must provide operating pressure to the bottom of the actuator cylinder. This port should always be connected to the bottom of the actuator cylinder.
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For the working pressure to or from the bottom of the actuator cylinder, the trip valve port F must provide a fail-mode outlet. This port should send to the environment for the fail-down mode. For the fail-up mode, this port should be connected to the volume tank. For the lock-in-last-position mode, this port should be plugged.