Manual Reset Relays: Product Details

Manual Reset Relays are basically two (2) position, directional flow control valves that require (1) manual positioning of the Stem assembly and (2) the application of operating Pilot Supply pressure, to achieve an "in-service" or normal operate status. A gain of instrument supply "output" pressure occurs in the receiving control circuit after the Manual Reset Relay becomes operational.

The most frequently utilized Manual Reset Relays are two position, three way Normally Closed, controls with a "spring return" (fail close) design feature. These Flow Control Valves (Relays) are commonly used in "Block & Bleed" (Quick Exhaust function) safety system, control circuit applications that monitor pneumatic or hydraulic, fault detection devices.

Manual Reset Relays are frequently referred to as "Group Master" or Two Phase (separate source Pilot Supply pressure and instrument supply or "output" pressure), directional flow control valves. They generally operate or directly control, the open/close sequence or operation of Surface Safety Valves (SSV) and other critical function Shutdown Valves (SDV).

The manual positioning of the Manual Reset Relay's Stem assembly is purposeful, to achieve an in-service or operating status. This deliberate (Manual Reset) effort insures acknowledgment of a fault monitoring response and that corrective action will be taken.