Fi-sher 377 Pressure-Sensing Trip Valve Pneumatic Emergency Shutdown Fail Safe Control Valve Trip Valve

The Fi-sher 377 is a pressure-sensing trip valve designed for control applications that require a specific actuator or valve action when supply pressure falls below a set trip point. It helps maintain process safety by causing the actuator to fail up, lock in the last position, or fail down, and automatically resets when supply pressure recovers.

This single-unit trip valve simplifies piping compared with systems using multiple switching valves. The trip point is adjustable, and the design uses large diaphragm areas with few moving parts for reliable performance and long service life. Available configurations include fail-down (377D), lock-in-last-position (377L), fail-up (377U), and rotary fail-close options (377CW / 377CCW). It can be mounted on a manifold, yoke, or bracket and is compatible with various Fi-sher piston actuators.

Used in process control systems across oil and gas, chemical, power generation, and other industries where reliable fail-safe actuator action is required upon loss of instrument air supply.

Users may face challenges with improper trip point setting, incorrect fail-mode piping, or volume tank sizing for certain configurations. The adjustable trip point and convertible fail modes help address these when correctly applied.

Serves as a direct replacement or functional upgrade for earlier Fi-sher trip valves or equivalent pressure-sensing trip devices in actuator protection circuits.

We supply genuine Fi-sher (E-merson) products and offer practical support for correct configuration selection based on actuator and process needs.

Typical production and delivery time is 6-8 weeks.

Please provide actuator type, desired fail mode, supply pressure range, material preference, and quantity for a tailored quotation.