water lines shall not bear directly against building structural elements so
as to transmit sound to the structure or prevent flexible movement of the
lines. Water pipe shall not be buried in or buried under floors unless
specifically indicated or approved. Buried pipe shall be inspected,
tested, and approved before backfilling. Changes in pipe sizes shall be
made with reducing fittings. Use of bushings will not be permitted except
for use in situations in which standard factory fabricated components are
furnished to accommodate specific accepted installation practice. Change
in direction shall be made with fittings, except that bending of pipe 100
mm 4 inches and smaller will be permitted provided a pipe bender is used
and wide sweep bends are formed. The center-line radius of bends shall be
not less than six diameters of the pipe. Bent pipe showing kinks,
wrinkles, flattening, or other malformations will not be acceptable.
3.2.5
Pipe Drains
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NOTE: Designer will indicate location of pipe
drains on the drawings.
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Pipe drains indicated shall consist of 20
mm 3/4 inch hose bibb with
renewable seat and [gate] [or] [full port
ball] valve ahead of hose bibb.
At other low points, 20 mm 3/4 inch brass
plugs or caps shall be provided.
Disconnection of the supply piping at the
fixture is an acceptable drain.
3.2.6
Expansion and Contraction of Piping
Allowance shall be made throughout for expansion and contraction of water
pipe. Each hot water and hot water circulation riser shall have expansion
loops where indicated and required. Risers shall be securely anchored as
required or where indicated to force expansion to loops. Branch
connections from risers shall be made with ample swing or offset to avoid
undue strain on fittings or short pipe lengths. Horizontal runs of pipe
over 15 meters 50 feet in length shall be anchored to the wall or the
supporting construction about midway on the run to force expansion, evenly
divided, toward the ends. Sufficient flexibility shall be provided on
branch runouts from mains and risers to provide for expansion and
contraction of piping. Flexibility shall be provided by installing one or
more turns in the line so that piping will spring enough to allow for
expansion without straining. If mechanical grooved pipe coupling systems
are provided, the deviation from design requirements for expansion and
contraction may be allowed pending approval of Contracting Officer.
3.2.7
Thrust Restraint
Plugs, caps, tees, valves and bends deflecting 11.25 degrees or more,
either vertically or horizontally, in waterlines 100 mm 4 inches in
diameter or larger shall be provided with thrust blocks to prevent
movement. Thrust blocking shall be concrete of a mix not leaner than: 1
cement, 2-1/2 sand, 5 gravel; and having a compressive strength of not less
than 14 MPa 2000 psi after 28 days. Blocking shall be placed between solid
ground and the fitting to be anchored. Unless otherwise indicated or
directed, the base and thrust bearing sides of the thrust block shall be
poured against undisturbed earth. The side of the thrust block not subject
to thrust shall be poured against forms. The area of bearing shall be as
shown or directed. Blocking shall be placed so that the joints of the
fittings are accessible for repair. Steel rods and clamps, protected by
galvanizing or by coating with bituminous paint, shall be used to anchor
SECTION 15405A
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