structure, pipe joints shall not be concealed, but shall be located where
they may be readily inspected and building structure shall not be weakened.
Avoid interference with other piping, conduit, or equipment. Except where
specifically shown otherwise, vertical piping shall run plumb and straight
and parallel to walls. Install piping connected to equipment to provide
flexibility for vibration. Support and anchor piping so that strain from
weight of piping is not imposed on equipment.
3.1.2.1
Fittings
Provide long radius elbows on welded piping to reduce pressure drops. Do
not miter pipe to form elbows, notch straight runs to form full sized tees,
or use similar construction. Make branch connections with welding tees,
except factory made forged welding branch outlets or nozzles having
integral reinforcements conforming to ASME B31.1 may be used.
3.1.2.2
Grading of Pipe Lines
Unless indicated otherwise, install horizontal lines of steam and return
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 flow may be either direction. Pitch air lines to the source
of supply, and make provisions for draining off condensate. Install water
lines to drain to a shutoff valve.
3.1.2.3
Anchoring, Guiding, and Supporting Piping
Anchor and support piping in a manner such that expansion and contraction
will take place in the direction desired, prevent vibration by use of
vibration dampeners, and prevent undue strains on boilers and equipment
served. Fabricate hangers used for support of piping of 50 mm 2 inch
nominal pipe size and larger to permit adequate adjustment after erection
while still supporting the load. Provide wall brackets where pipes are
adjacent to walls or other vertical surfaces which may be used for
supports. Provide supports to carry weight of lines and maintain proper
alignment. Provide inserts and sleeves for supports in concrete where
necessary and place in new construction before pouring concrete. Provide
insulated piping with a pipe covering protection saddle at each support.
Provide pipe guides and anchors of approved type at points where necessary
to keep pipes in accurate alignment, to direct expansion movement, and to
prevent buckling and swaying and undue strain. Provide pipe guides for
alignment of pipe connected to free unanchored end of each expansion joint.
Support pipe rollers in concrete conduits and trenches by extra strong
steel pipe with ends inserted in slots provided in concrete walls. Set
pipe supports for rollers at correct elevations either by metal shims or by
cutting away of concrete and after placing pipe lines in alignment, grout
ends of pipe supports and fix in place. Space pipe supports to provide
adequate support for pipes. Pipe shall not have pockets formed in the span
due to sagging of pipe between supports, caused by weight of pipe, medium
in pipe, insulation, valves, and fittings. Maximum spacing for pipe
supports for steel pipe shall be in accordance with ASME B31.1; maximum
spacing for supports for copper tubing shall be in accordance with MSS SP-69.
3.1.2.4
Copper Tubing
Copper tubing shall have solder joints with solder suitable for the
pressure-temperature ratings of the piping system. Tubing 20 mm 3/4 inch
and smaller for instrument air may be compression joint in lieu of soldered
joint. Tin-antimony (95/5) solder is suitable for saturated steam up to
SECTION 15511N
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