MIL-PRF-9439F
to the closed position. The torque required at the handwheel to open or close the valve shall be
not greater than 60 inch-pounds.
4.6.5 Flow. A constant gas pressure of 100 psig shall be applied to the valve inlet and a
constant back pressure of 30 inches of mercury shall be applied at the valve outlet (see 6.4). The
flow through the fully open valve outlet shall be not less than 708 SLPM. Flow through the valve
shall also be reversed and verified.
4.6.6 Leakage. With the valve closed, the outlet capped, and a minimum pressure of
2,200 psig being maintained at the valve inlet, the valve shall be fully opened (¼ to one turn) and
immersed in water. There shall be no leakage from the valve stem or outlet. While immersed, the
valve shall be turned to the half-closed position. There shall be no leakage from the valve stem or
outlet. The valve shall then be closed with a torque not greater than 60 inch-pounds, the outlet
uncapped and the valve immersed in water. After immersion for 1 minute, there shall be no
leakage from the outlet. Leakage is indicated by a breakaway of bubbles (see 6.9).
4.6.7 High temperature exposure. The valve shall be exposed to a temperature not less
than 160oF for 3 hours. After this exposure and while maintained at this temperature, the valve
shall be subjected to the torque, flow, and leakage tests (see 4.6.4, 4.6.5, and 4.6.6).
4.6.8 Low temperature exposure. The valve shall be exposed to a temperature not
greater than -65oF for 3 hours. After this exposure and while maintained at this temperature, the
valve shall be subjected to the torque, flow, and leakage tests (see 4.6.4, 4.6.5, and 4.6.6). The
valve shall be immersed in a solution during the leakage test that will not freeze at -70oF and has
a viscosity not greater than 1 centipoise at 20oC.
4.6.9 Proof pressure. The valve shall be closed with a torque not greater than 60 inch-
pounds, the outlet uncapped, and the overpressure safety device replaced by a solid plug or cap.
A water pressure of 3,000 psig shall be applied to the valve inlet. While the pressure is being
maintained for 5 minutes, the valve shall not leak or distort. Then, the valve outlet shall be
capped and 3,000 psig water pressure applied to the valve inlet. While maintaining the pressure
for 5 minutes, the valve shall be turned to the open position and examined for leakage or
distortion. The valve shall not exhibit any evidence of leakage or distortion, or require a torque
greater than 60 inch-pounds to open the valve.
4.6.10 Endurance. With the outlet of the valve capped, and a minimum gas pressure of
2,200 psig at the valve inlet, the valve shall be cycled 250 times at a constant rate of one cycle
per minute. Turning the handwheel from the closed position to the opened position and back to
the closed position shall constitute one cycle. After completing 250 cycles, the valve shall be
subjected to the torque and leakage tests (see 4.6.4 and 4.6.6).
4.6.11 Vibration. The valve shall be vibrated along each of three mutually perpendicular
axes of the valve for 1 hour with the frequencies being varied from 10 to 40 Hz, and back to 10
Hz in approximately 1 minute intervals at a double amplitude of 0.018 to 0.020 inch. After the
third axis is cycled, the valve shall be closed, the outlet capped, and a gas pressure of 2,200 psig
applied to the inlet. With the gas pressure maintained the valve shall be vibrated as specified
7
For Parts Inquires call Parts Hangar, Inc (727) 493-0744
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business