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2.2 Water/Glycol Cooled Unit Piping
The required fi eld installed condenser water pipe sizes may or may not be the same as the connection
sizes at the evaporator or fl uid cooler. This will depend on the length of pipe and the calculated
pressure drop of peripheral components.
Water cooled units may also be connected to building water or tower water sources. Pipe size will
depend on length of run and the maximum water fl ow required.
All chilled water pipes have a cap installed on the end of the pipe for pressure testing the system,
these caps need to be removed before installing the water piping to the CRAC unit. This can be
accomplished with a tubing cutter for smaller pipes and reciprocating saw with a metal cutting blade
for larger pipes or if there is a clearance problem.
Shutoff valves, fi eld provided, should be installed within a few feet of the inlet and outlet connections
of the CRAC unit to allow the unit to be isolated for service. There should be a means of draining
the unit for service. Drain valves with hose bib connections should be located at the lowest point
on the piping connected to the units for this purpose. A fi ll valve with a hose bib connection should
also be used on the supply line or return line at the unit to allow the unit to be drained.
All water/glycol cooled units with plate-fi n type condensers have a strainer shipped loose. This
strainer should be fi eld installed in the supply line with shut off valves, fi eld provided, before and
after the strainer, the strainer must be cleaned periodically.
One of the most common problems in a water/glycol system is the presence of air in the
condenser water loop. Air vents must be installed in various locations in the piping system
to purge the air.
