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* (OPTIONAL) WATER CONTROL VALVE AND WATER SHUTOFF VALVE MUST BE ORDERED SEPARATELY.
FIGURE 2–7 – SERIES PIPING FIGURE 2–8 – PARALLEL PIPING
blowdown valve piped to the outside with a pipe size the
same as the blowdown valve outlet connection.
WATER PIPING (Water–Cooled Heat Exchanger
Models Only) – On machines equipped with water–
cooled heat exchangers, the water inlet and outlet con-
nections are located in the unit base flange on the left
side of the unit.
It is mandatory that any water cooled
unit be installed in a shelter heated to
temperatures above freezing (32_ F.,
0_ C).
The water source should be capable of supplying up to
the maximum flow shown in FIGURE 2–5, page 11,
and FIGURE 2–6, page 12, at a minimum pressure of
40 psig (2.8 Bars); maximum allowable water pressure
is 150 psig (10.3 Bars). The water flow rates shown are
approximate and a guide to sizing piping, cooling tower
and other water system equipment.
The heat exchanger system is designed to operate with
water inlet temperatures from 60_ to 90_ F (16_ to 32_
C) and a water outlet temperature not to exceed 110_F
(43_ C). If water cooler than 60_ F is used, high water
outlet temperatures (over 110_ F, 43_ C) will be experi-
enced along with shortened heat exchanger life caused
by tube fouling and corrosion. If water warmer than 90_
F (32_ C) is used, higher compressor oil inlet tempera-
tures and high water usage will result.
Most water systems will require control of impurities:
filtration, softening or other treatment. See “Compres-
sor Oil Cooler – Water–Cooled Heat Exchanger” for
more information on the water system.
SERIES PIPING (FIGURE 2–7) – Water flow must be
through aftercooler first for effective cooling of dis-
charge air and is so piped on the standard water–
cooled unit.
PARALLEL PIPING (FIGURE 2–8) – A separate wa-
ter control valve is required to control the discharge air
temperature. If a remote (externally mounted) water–
cooled aftercooler is piped in parallel with the heat ex-
changer, provide a separate water control valve for the
aftercooler and pipe separate inlet water lines to both
the aftercooler and heat exchanger.
The water control valve is to be adjusted to maintain oil
out of the heat exchanger within the 140_ to 150_ F
(60_ to 66_ C) range regardless of inlet water flow or
temperature as long as a minimum flow for a given tem-
perature is met (FIGURE 2–5, page 11, and
FIGURE 2–6, page 12. See Section 5, page 33, for ad-
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