MIL-HDBK-1003/3
Exterior Distribution of Utility Steam, High Temperature Water
(HTW), Chilled Water, Natural Gas and Compressed Air. For
information on piping flexibility design, refer to Crocker,
Piping Handbook, Kellogg, Design of Piping Systems, or similar
references.
7.1.6
Expansion Loop. On straight pipes, always use
expansion loops if space conditions permit.
7.1.7
Packing-Type Expansion and Ball Joints. Provide
packing-type expansion and ball joints only if they can be
located in accessible areas. These expansion joints shall not be
used for refrigerant piping. Packing-type expansion joints can
be used, however, for chilled water, hot water, or steam lines
under limited conditions. Packing-type joints fail slowly,
giving a warning by leakage.
7.1.8
Bellows Expansion Joints. Use bellows-type expansion
joints where piping is not easily accessible. Bellows-type
joints can fail suddenly without warning and should not be used
where personnel would be endangered by a rupture.
7.1.9
Supports and Anchors. Expansion joints should be
provided with guides to prevent undue bending movement. Piping
between expansion joints should have supports designed to carry
the weight of the pipe and fluid together with axial friction
loads and the thrust of the expansion joint. Risers and mains
should be anchored to prevent excessive strain on branches.
Consider whether the building structure will withstand the thrust
of piping on the anchor. In light steel or wood frame
structures, consider allowing the piping system to float with
expansion loops but without anchors.
a) Supports. Provide shields between the insulation
and the supports of insulated piping. Provide roller-type guided
supports where horizontal pipe is subject to thermal expansion.
Provide vertical pipes and main risers with base elbows designed
to take the weight of the pipe from the elbow up to the first
anchor.
b) Hangers. Provide hangers with vibration isolators,
as required. Hangers shall be massive enough to limit the
vibration amplitude. Pipe supports shall be wide enough to avoid
any swivel action. Use spring hangers when required to
accommodate expansion in vertical piping. Provide seismic
support in the lateral direction where this is appropriate.
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