Fisher 377 pressure‐sensing trip valves are for control

applications where a specific valve/actuator action is

required when supply pressure falls below a specific

point. When supply pressure falls below the trip point

(see figure 1), the trip valve causes the actuator to fail

up, lock in the last position, or fail down. When the

supply pressure rises above the trip point, the 377 trip

valve automatically resets, allowing the system to

return to normal operation. The trip valve can be

top‐mounted on a manifold, yoke‐mounted, or

bracket‐mounted to match the application

requirements. 377 trip valves can be used with Fisher

480, 585C, 685, 1061, 1066, 1069, and Bettis-G

Series piston actuators.