Model 77-8 three-way transfer valve

Features

The Model 77-8 three-way transfer valve is used alone or with differential gap controllers, lockup valves, and other equipment in pneumatic control circuits to add flexibility to devices such as valves, load applicators, and instruments. A pneumatic signal or air supply is piped to a springopposed diaphragm, which actuates a double-faced soft seat plug. As long as a pressure exists at one of the signal ports (S) in excess of the set pressure of the unit, the normally open port (NO) is closed and flow through the valve is from the common port (C) to the normally closed port (NC) or from NC to C. When the signal pressure falls below the set valve, the spring closes port NC and opens NO to allow flow from port C to port NO, or from port NO to port C. Signal pressure is sealed off from the valve body by an O-ring.

Specifications

Connections: Screwed - 1/2" NPT
Materials: Die-cast aluminum
Rating: 250 psi @ 150°F
Valve seats: Brass
Plug assembly: Brass with Buna-N inserts
O-ring seals: Buna-N