flow pilot with an adjustable time delay relay arranged so
that the high flow will not open for a period of 1 to 2
minutes after the start of flow and will stop the flow with a
high flow, low flow sequence. On Air Force projects, use a
diaphragm control valve which has only opening and closing
22.214.171.124 Remote Operations. Hydraulically operated diaphragm
control valves can be operated remotely. This is accomplished
by installing tubing from the point of pressure sensing to the
valve or by using remote-controlled solenoids within the trim.
126.96.36.199 Materials of Construction. Use stainless steel or
aluminum (in non-contained areas) pilot control valves and
stainless steel tubing. Use bodies, bonnets, and covers made
of aluminum, stainless steel, internally plated (chromium)
cast steel, or internally plated (nickel) nodular iron.
Provide viton or Buna-N diaphragm and disc ring. Enclose all
electrical apparatus according to classification of the area
in which they are installed. Provide a means to wire seal all
adjustable pilots. Do not use aluminum valves and tubing
within an area that may collect flammable or combustible
188.8.131.52 Applications. For fueling systems, use
hydraulically operated diaphragm control valves in the
following applications (also refer to specific sections for
a) Water slug shutoff.
b) Rate of flow control.
c) Pressure reduction.
d) Pressure relief.
e) Liquid level control.
f) Non-surge check control.
g) Deadman control.
h) Electrical block control.