not use mitering of pipe to form elbows, notching straight runs to form
full sized tees, or any similar construction. Make branch connections over
50 mm 2 inches with welding tees except factory made forged welding branch
outlets or nozzles having integral reinforcements conforming to ASME B31.9
may be used, provided the nominal diameter of the branch is at least one
pipe size less than the nominal diameter of the run. Branch connections 50
mm 2 inches and under can be threaded or welded. Run vertical piping plumb
and straight and parallel to walls. Provide sleeves for lines passing
through building structure. Provide a fire seal where pipes pass through
fire wall, fire partitions, fire rated pipe chase walls, or floors above
grade. Install piping connected to equipment with flexibility for thermal
stresses and for vibration, and support and anchor so that strain from
weight and thermal movement of piping is not imposed on the equipment.
3.2.1
Hangers and Supports
Unless otherwise indicated, horizontal and vertical piping attachments
shall conform to MSS SP-58. Band and secure insulation protection shields
without damaging pipe insulation. Continuous inserts and expansion bolts
may be used.
3.2.2
Grading of Pipe Lines
Unless otherwise indicated, install horizontal lines of hot water piping to
grade down in the direction of flow with a pitch of not less than 25 mm in
9 meters one inch in 30 feet, except in loop mains and main headers where
the flow may be in either direction.
3.2.3
Pipe Sleeves
Provide sleeves where pipes and tubing pass through masonry or concrete
walls, floors, roof, and partitions. Annular space between pipe, tubing,
or insulation and the sleeve shall not be less than 6 mm 1/4 inch. Hold
sleeves securely in proper position and location before and during
construction. Sleeves shall be of sufficient length to pass through entire
thickness of walls, partitions, or slabs. Sleeves in floor slabs shall
extend 50 mm 2 inches above finished floor. Firmly pack space between pipe
or tubing and sleeve with oakum and caulk on both ends of the sleeve with
plastic waterproof cement which will dry to a firm but pliable mass, or
provide a [mechanically adjustable] segmented elastomeric seal. Seal both
ends of penetrations through fire walls and fire floors to maintain fire
resistive integrity with UL listed fill, void, or cavity material.
3.2.4
Flashing for Buildings
Provide flashing where pipes pass through building roofs, and make outside
walls tight and waterproof.
3.2.5
Unions and Flanges
Provide unions and flanges to permit easy disconnection of piping and
apparatus. Each connection having a screwed-end valve shall have a union.
Place unions and flanges no farther apart than 30 meters 100 feet. Install
unions downstream of valves and at equipment or apparatus connections.
Provide unions on piping under 50 mm 2 inches in diameter, and provide
flanges on piping 50 mm 2 inches and over in diameter. Provide dielectric
unions or flanges between ferrous and non-ferrous piping, equipment, and
fittings; except that bronze valves and fittings may be used without
dielectric couplings for ferrous-to-ferrous or non-ferrous-to-non-ferrous
SECTION 15185N
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