MIL-HDBK-1022A
d) On the product pipeline or header just before the
line leaves a pumping station.
e) On the suction side and discharge side of each
pumping unit, except the suction side of vertical centrifugal
pumps installed in underground tanks.
f) On the upstream and downstream side of each line
blind at connections to cross country pipelines.
g) On the inlet and outlet connection of each line
strainer, filter/separator, meter, automatic valve, and other
equipment that requires periodic servicing. One inlet valve
and one outlet valve may be used to isolate more than one
piece of adjacent equipment which are connected in series.
h) On each main distribution pipeline immediately
downstream of the branch connection to each existing or future
operating storage facility served by the pipeline.
i) On the aboveground piping at each tank car or
tank truck off-loading connection. This requirement does not
apply to gravity off-loading lines unless block valves are
specifically called for on applicable standard drawings.
j) On the aboveground piping at each tank car and
tank truck loading connection.
k) At critical roadway, runway, and taxiway
crossings, consider isolation valves on both sides of
runway/taxiway to facilitate hydrostatic testing and
isolation.
3.6.9.6
Valve Pits. Provide fiberglass or concrete pits
with a rolling or hinged cover designed in accordance with the
Air Force Standard Design AW 78-24-28 for all valves installed
in non-traffic areas on underground fuel systems.
3.6.10
Hydraulically Operated Diaphragm Control Valves.
Diaphragm-operated globe valves are used extensively in
fueling systems as control valves. These valves consist of a
main valve and a pilot control system. The main valve
consists of a body, diaphragm, and cover and is operated by
varying the amount of pressure above the diaphragm. Since the
chamber above the diaphragm exposes a greater area of the
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