Piping. For design of power plant piping and selection of piping materials,
see ANSI/ASME B31.1, Power Piping (ASME Code for Pressure Piping). See also MIL-HDBK-
1003/8, Exterior Distribution of Utility Steam, High Temperature Water (HTW), Chilled
Insulation, Lagging, and Jacketing
Insulation. Insulation shall be non-asbestos composition and shall be applied
to piping, equipment, and ductwork to conserve energy and for comfort and safety.
value of heat energy saving versus the cost of additional thickness of insulation.
For additional information, see MIL-HDBK-1003/6.
Lagging. Metal lagging is used to cover insulation applied to breeching,
ductwork, scrubbers, baghouse filters, electrostatic precipitators, large fans, and
other equipment having large flat surfaces. Lagging can be aluminum, aluminized steel,
galvanized steel, or stainless steel in a variety of profiles with the selection
depending on the application and exposure. Lagging can be plain, corrugated, embossed,
unpainted, or painted with a variety of finishes.
Lagging surface temperature shall not exceed 150 degrees F (66 degrees C).
Jacketing. All insulated piping and equipment should be completely covered
with aluminum or stainless steel jacketing. Aluminum jacketing should not be used for
piping in trenches or buried directly in the ground.
with copper, copper alloys, tin, lead, nickel, or nickel alloys including Monel metal.
Freeze Protection. Piping that is subject to freezing shall be protected with
electric heating cable. Follow manufacturer's recommendations and instructions for
Pipe Supports. Use rigid (rod or roller) or spring type pipe hangers for
supporting overhead piping. Piping located near floors, platforms, or other suitable
surfaces is often supported from below by rigid floor stands. See Federal Specification
WW-H-171E, Hangers and Supports, Pipe, for type selection. See also MIL-HDBK-1003/8.
Locate anchors to control heat pipe movement or to limit movements of branch
takeoffs from a main line.