MIL-HDBK-1022
at normal water level. This affords greater stiffness and
resistance to buckling during handling of the assembled
crossing pipe and requires less weighting material to obtain
the necessary negative buoyancy to keep the line in place
while empty or containing a light product. Reinforced
sprayed-on concrete is an acceptable weighting material.
Hydrostatically test assembled crossing pipe before placing,
unless crossing pipe is too long for prior assembly in one
segment. In this case, separately test each segment as
described.
9.5
PIPING MATERIALS
9.5.1
Non-Aviation Systems. Use carbon steel piping
material for interterminal pipelines (regardless of product)
and for all portions of non-aviation turbine fuel systems,
except FRP may be used for underground pipe (not in concrete
trenches) in ground vehicle fueling facilities. The
appropriate service guide specification includes the necessary
requirements.
9.5.2
Aviation Systems. For new systems, use stainless
steel or aluminum piping downstream of the last issue
filter/separator. Limit aluminum to aboveground pipes of 12
inches (300 mm) or less nominal pipe size. Give special
consideration to the pressure rating of both the pipe and
fittings to ensure adequacy to accommodate surge pressure. Do
not allow copper, copper alloys, light metal alloys containing
more than 4 percent copper, zinc or zinc alloys, cadmium, or
lead or lead alloys in components exposed to the fuel. Brass
hose couplers are permitted. Metals are restricted to protect
the thermal stability property of aviation turbine fuels. See
Facility Plate No. 025 for piping material options.
9.6
WELDING CRITERIA. Ensure that the contract requires
welding and welding inspections in accordance with appropriate
guide specifications and/or standard design. Use 100 percent
radiographed weld joints meeting the standards for severe
cyclic service contained in ANSI/ASME B31.3 for piping
downstream of the pump in hydrant systems. For all other
underground steel pipes, use 100 percent radiographed weld
joints meeting the requirements of ANSI/ASME B31.4.
9.7
PIPING CONNECTIONS
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