MIL-HDBK-1022
within the tank dike area. Carbon steel valves are permitted,
provided they are internally plated with chromium.
Electroless nickel plating is also acceptable. Internally
epoxy-coated valves are acceptable for general services but do
not use as a substitute for a non-ferrous valve. Do not use
aluminum valves within a diked area. Do not furnish nor
install cast iron or bronze-bodied valves in liquid petroleum
service. Use only API fire-safe valves for fuel service.
4.7.9.2
Types
a) Gate valves are not allowed on systems covered by
this section.
b) Valves for quick or frequent opening may be one
with the following types:
(1) Ball valves designed so that if the synthetic
seating material is burned out in a fire, a metal-to-metal
seat will remain to affect closure and comply with API Std
607. Where line pigging is required or if within ten pipe
diameters upstream and/or five pipe diameters downstream of a
flow control valve, pressure control valve, or a flow-sensing
device such as a venturi, use full port ball valves. Valves
should comply with API Std 608.
(2) High-performance wafer trunion valves
(butterfly). Use Teflon or viton synthetic seals or seating
material. Require valves that are designed so that if the
synthetic seating material is burned out in a fire, a metal-
to-metal seat will remain to affect closure. Use valves of
high-performance type with eccentric disc shaft and clamping
action for bubble-tight shutoff. Do not use these valves on
Air Force projects. On projects for other services, use only
as operating valves and not where isolation or absolute
closure is required, such as on tanks. Their use is
discouraged outside of aircraft direct fueling stations and
fill stands with fusible links.
c) Use check valves to prevent backflow through
branch lines, meters, or other locations where runback or
reverse flow must be avoided. Check valves may be of the
swing disk, spring-loaded poppet, ball, or diaphragm-actuated
types. Use swing checks of soft-seated non-slamming type with
90
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