MIL-HDBK-1022
not use expansion devices which employ packings, slip joints,
friction fits, or other non-fire resistant arrangements. Use
ball-type offset joints to accommodate possible settlement of
heavy structures such as storage tanks, if piping design
cannot provide enough flexibility. Design expansion bends,
loops, and offsets within stress limitations in accordance
with ANSI/ASME B31.3 and ANSI/ASME B31.4.
9.2.4
Anchors. Anchor aboveground piping at key points so
expansion will occur in the desired direction. Anchors and
guides may also be required to control movement in long runs
of straight pipe or near a connection to fixed equipment such
as a pump or filter. See Facility Plate Nos. 023 and 024.
Space anchors to provide maximum amount of straight runs of
piping from expansion points to the anchors. In general,
place anchors at all points of the system where only minimum
piping movement can be tolerated, such as at branch
connections and equipment connections. Key locations are pump
houses or other buildings, manifolds, at changes of direction
if not used as an expansion joint, at points where the pipe
size is drastically reduced related to adjacent piping, and at
all terminal points. Limit the use of anchors to the
situations described above. Where an anchor is welded
directly to a pipe, ensure that the anchor material is
compatible with the pipe material. Do not allow welding of
Schedule 10 stainless steel pipe to an anchor.
9.2.5
Relief Valves. Provide relief valves to relieve
excessive pressures caused by thermal expansion of the liquid
in the pipe between shutoff points. The coefficient of
expansion of liquid petroleum in the range of 35 degrees to 60
degrees API (0.8498 to 0.7389) at 60 degrees F (16 degrees C)
is 0.0005 inch per inch per degree F (0.0009 mm per mm per
degree C). Provide line valves with relief valve bypasses to
relieve increased pressures caused by solar or other heating
of static fluids in closed-off pipe segments and equipment.
For remotely controlled valves, located where excessive bonnet
pressure can develop when in the closed position, provide
relief valves on the bonnets. Ensure relief valves do not
discharge to grade or to a stormwater drainage system. A
relief valve should ideally discharge directly into a storage
or holding tank at atmospheric pressure. Alternatively, any
relief valve may be connected to discharge to tankage through
one or more successive adjacent pipe segments. Use extreme
care when following this method to verify that the total
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