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WHAT IS IT?
 This unit is a two position, 3 way, Poppet Type Solenoid Valve with an Integral Relief Valve. The Valve Body is Cast Aluminum but the steel Poppets and Seats are enclosed in a steel sleeve. All materials are compatible with Turbine Engine Fuel, Diesel Oil and Gasoline. The D.C. Solenoid is designed to take advantage of 14 to 30 VDC opening Voltage and to securely hold the Valve in place with only 8 VDC, a feature required to conserve power and to minimize heat. The Relief Valve provides both relieving and checking functions. It is isolated in the line from Lines to Port #3.
The Relief Valve is set to crack at 30 PSID and reset at 20 PSID. Total pressure drop from Port #2 (Supply) to Port #3 (including the Relief Valve) is 50 PSID Max and to Port #1 is 35 PSID at a rated Fuel flow of 800 P.P.H. |
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HOW DOES IT WORK?
 Energizing the Solenoid shifts the twin Poppet arrangement to the opposite Steel Seat, closing the Outlet Port and opening the other. The Poppets are in contact but free to move radially to allow each to independently seek the center of its respective Seat. Dynamic Seals are the "Glyd Ring" Type for low friction. The Poppet and Relief Valve employs an entrapped "O" ring as the seal. Total stroke of the Valve is .021 inches. The opening and closing response times are therefore quite low, on the order of 20 ms or less. The Solenoid has a 30 ohm resistance at 76 degrees F and draws 1.36 amps at -70 degrees F. All "wetted" surfaces are either Stainless Steel, Aluminum or Nickel Plated for corrosion protection. |
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| HOW IS IT USED? |
| This unit is used in a Turbine Engine Fuel Control as the Main Shut-off Valve. The fuel pump output is directed into the Engine past the Relief Valve during start-up and normal running periods. The Relief Valve prevents fuel flow during the start-up until a predetermined minimum manifold pressure is reached thus reducing premature or excessive fuel delivery prior to light-off. The Valve, when de-energized, shuts off all fuel to the Engine and vents residual fuel pressure back to Pump return. |
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