pumps and flanged valves.
**************************************************************************
NOTE: Insulate indoor piping subject to
condensation and aboveground exterior piping subject
to freezing.
**************************************************************************
c.
Piping to Receive Insulation: Provide temporary wood spacers
between the pipe hangers and supports, and the pipe to properly
slope the piping and establish final elevations. Provide
temporary wood spacers of same thickness as insulation to be
provided under Section 15080 THERMAL INSULATION FOR MECHANICAL
SYSTEMS.
d.
Cleaning of Piping: Keep interior and ends of new piping and
existing piping, affected by Contractor's operations, cleaned of
water and foreign matter during installation by using plugs or
other approved methods. When work is not in progress, securely
close open ends of pipe and fittings to prevent entry of water and
foreign matter. Inspect piping before placing into position.
3.2.1
Flushing the Aboveground Piping
Before connection of the header to the polyethylene [or polybutylene]
ground heat exchanger loops, flush the entire aboveground piping system
thoroughly in accordance with IGSHPA 21020 recommendations and leave filled
with clean water. If the header is not immediately joined to the ground
heat exchanger loop, the open ends shall be taped or capped.
3.3
GROUND HEAT EXCHANGER PIPING
Examine areas and conditions under which ground heat exchanger systems will
be installed. Prior to excavation, trenching, or drilling, locate and mark
buried utilities. Do not proceed with work until approved by the
Contracting Officer. Avoid sharp bends in piping. Provide fittings for
changes in direction when minimum bend radius, as recommended by the pipe
manufacturer, is exceeded. Use only continuous pipe in sharp bends. Make
changes in piping sizes through tapered concentric fittings. Leaks shall
be "cut-out" and repaired in accordance with the pipe manufacturer's
recommendations. Direct buried threaded connections are not permitted.
3.3.1
Vertical Well Fields
Each U-bend loop shall be assembled, laid out straight, taped to reduce
springback, and water pressure tested at 689 kPa 100 psi for leaks and flow
by IGSHPA 21020 recommended procedures before the hole is bored. Vertical
bores shall be 1.5 m 5 feet deeper than the length of the loop and shall be
clean (no casing) and of sufficient diameter to facilitate the installation
of the U-bend assembly and a third pipe for pressure grouting. Fill the
loop with water and pressurize to 276 kPa 40 psi to prevent the pipe from
being crushed by backfill material. Backfill the bores from the bottom up
with a high solid bentonite grout material and grouting process in
conformance with IGSHPA 21010 to ensure pipe contact and compliance with
local and State requirements for sealing. Bentonite grout shall be
prepared in accordance with manufacturer's recommendations for water-to-mix
ratio. The bores shall not contain large, sharp, or jagged rocks or
debris. Take reasonable and prudent care during installation and
backfilling to not crush, cut, or kink the pipe.
SECTION 15741N
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