Fi-sher 377 Pneumatic Pressure Trip Valve Control Valve Safety Device Valve Trip Valve

Fi-sher 377 Series Trip Valve

The Fi-sher 377 pressure-sensing trip valve provides automatic fail-safe action for pneumatic actuators when instrument air supply pressure drops below a predetermined level. Upon recovery of supply pressure, the unit resets automatically to restore normal control.

Product Overview

A single 377 trip valve can perform the functions that previously required multiple switching valves, reducing complexity and spare parts. Fail modes (up, down, or lock-in-last-position) are selectable with minor piping changes. The design emphasizes large diaphragms, minimal moving parts, and durable construction in aluminum or stainless steel. It is suitable for use with Fi-sher 480, 585C, 685, 1061 and similar piston actuators, with mounting options for manifold, yoke, or bracket installation.

Technical Specifications

Application Industry

Applied in process plants requiring reliable actuator protection, including refining, petrochemical, power, and general industrial control systems that depend on instrument air.

Common Problems

Common issues include incorrect volume tank selection for fail-up/down modes or mismatch between trip setting and system pressure. Proper configuration and the unit’s adjustable trip point help resolve these during installation and commissioning.

Replacement Models

Compatible as a replacement for other Fi-sher trip valves or similar pressure-sensing protection devices in existing actuator systems.

Why Buy From Us

We focus on authentic Em-erson Fi-sher instrumentation and provide knowledgeable assistance for trip valve selection and application matching.

Stock & Delivery Time

Standard lead time is 6-8 weeks.

RFQ Form

Submit your required fail action, actuator model, operating pressure, temperature conditions, and material needs for a detailed quote.