fisher 377 trip valve and volume tank

Fisher 377, 377D, 377U, 377CW, 377CCW Pressure-Sensing Lockup Valves – Genuine Fisher Products

Fisher pneumatic control products are suitable for applications requiring protection for equipment or final control elements under working conditions. The Fisher 377 pressure-sensing lockup valve is designed for control applications where air supply pressure falls below a specified level, necessitating special valve/actuator operation. When the air supply pressure drops below the trigger point, the lockup valve will prevent the actuator from rising or descending, effectively locking it in its last position. Once the air supply pressure rises above the trigger point, the 377 series lockup valve will automatically reset, allowing the system to return to normal operation.

The lockup valve can be top-mounted on manifolds or mounted to valve stems or brackets to suit various application needs.

Cost-Effective Solution — Compared to a system using three separate switching valves to perform failure functions, a single lockup valve can reduce costs and spare parts requirements. A single lockup valve also simplifies pipeline requirements.