13–11–602 Page 15
FIGURE 2–9 – WATER CONTROL VALVE
with cooling water in the tubes and compressor injec-
tion water in the shell. The optional cooling water con-
trol valve may be used to conserve water.
Compressor injection water cooler malfunction may be
traced by checking the pressure at the compressor in-
jection water inlet and outlet. At normal operating air
service pressure (65 to 125 psig – 4.5 to 8.6 bars) with
the unit warm, a pressure drop of 3 to 5 psi (.2 to .3 bar)
can be expected.
Cooling water pressure drop from inlet to outlet will vary
with the inlet pressure and amount of cooling water
flowing through the cooler. A normal pressure drop
may range from 5 to 10 psi (.3 to .7 bar). Any change
in the pressure drop may indicate tube leakage or foul-
ing and should be investigated.
In many instances, the cooling water supply for the heat
exchanger will contain impurities in solution and/or sus-
pension. These substances can cause scale forma-
tion, corrosion and plugging of any water–cooled heat
exchanger equipment. Disregarding the possibility that
one or more of these conditions exist may result in in-
creased maintenance and operation expense, reduced
equipment life and emergency shutdown. It is strongly
recommended that a reputable, local water treatment
concern be engaged to establish the corrosion, scale
forming and fouling tendency of the cooling water and
take steps necessary to remedy the situation if a prob-
lem does exist. The need for water treatment may in-
volve only filtration (screening) to remove debris, sand
and/or salt in the cooling water supply. However,
chemical treatment methods may be necessary in cer-
tain instances to inhibit corrosion and/or remove dis-
solved solids, to alter the water’s tendency to form
scale deposits, or prevent the growth of microorgan-
isms. The normal maintenance program for the unit
should also include periodic cleaning of the tubes (wa-
ter side) of the heat exchanger to remove deposits
which enhance fouling and corrosion.
Hex head zinc anodes are used in the return bonnet
(opposite end to the water pipe connections) of heat ex-
changers to provide internal water system corrosion
protection. These anodes should be inspected periodi-
cally and replaced when the zinc has been reduced to
about 1/2 inch (12 mm) in length.
WATER FLOW CONTROL VALVE FOR HEAT EX-
CHANGER (Optional Equipment) (FIGURE 2–9) –
The cooling water flow control valve is adjustable to
compensate for varying cooling water inlet tempera-
tures and pressures and is to be mounted in the cooling
water outlet line after the compressor injection water
cooler (FIGURE 2–6 and FIGURE 2–7, pages 13 and
14). Use the compressor discharge air temperature
gauge on the instrument panel in setting the flow con-
trol valve.
To decrease water flow (increase compressor dis-
charge air temperature) turn the adjusting screw from
left to right, increasing spring tension. To increase wa-
ter flow (decrease compressor discharge air tempera-
ture) turn the adjusting screw in the opposite direction.
The groove at the lower edge of the adjusting screw is
an index line for use with the index scale 0 to 8 in obtain-
ing a desired setting.
These valves must be handled with care and proper
tools and techniques must be used when working on
the valve.
Care must be used when handling the capillary tube; a
kink or break in the tubing or connections will make the
valve inoperative. Never attempt to change capillary
length. Excess capillary tube should be carefully coiled
and placed so that damage will not occur in normal
maintenance or traffic past the unit.
If the leak develops through the packing, tighten the
packing gland nut firmly with a wrench to reseat the
packing around the valve stem, then back off the nut
until loose, and finally retighten the nut finger tight.
Tightening the packing nut too tight may cause erratic
operation. An occasional drop of oil on the valve stem
at the packing nut will prolong packing life.
If the valve malfunctions, check for bends, binding,
paint or corrosion on the valve stem, foreign material
in the valve, erosion, or thermal system (capillary) fail-
ure. If foreign material or scale is likely, the use of a
strainer in the inlet water line is recommended.
COOLING WATER SHUTOFF VALVE – WATER–
COOLED HEAT EXCHANGER (Optional Equipment)
(FIGURE 5–2, page 43) – A magnetic solenoid–oper-
ated cooling water shutoff valve rated at 150 psig (10.3
Содержание TWISTAIR EWDQ D
Страница 14: ...13 11 602 Page 4 FIGURE 1 6 AIR WATER SCHEMATIC FIGURE 1 7 OIL SCHEMATIC...
Страница 17: ...13 11 602 Page 7 DECALS 206EAQ077 212EAQ077 218EAQ077 211EAQ077 207EAQ077...
Страница 18: ...13 11 602 Page 8 DECALS 216EAQ077 206EWD077 222EAQ077 221EAQ077 208EAQ077...
Страница 35: ...13 11 602 Page 25 FIGURE 4 2 FLOW CHART FOR SET UP PROGRAMMING...
Страница 44: ...13 11 602 Page 34 FIGURE 4 6 CONTROL TUBING SCHEMATIC 206EWD797 A Ref Drawing...
Страница 46: ...13 11 602 Page 36 FIGURE 4 8 CONTROL SCHEMATIC COMPRESSOR UNLOADED CONSTANT SPEED MODE 208EWD797 A Ref Drawing...
Страница 47: ...13 11 602 Page 37 FIGURE 4 9 CONTROL SCHEMATIC COMPRESSOR UNLOADED LOW DEMAND MODE 209EWD797 A Ref Drawing...
Страница 48: ...13 11 602 Page 38 FIGURE 4 10 WIRING DIAGRAM FULL VOLTAGE 202EWD546 REF DRAWING...
Страница 49: ...13 11 602 Page 39 FIGURE 4 11 WIRING DIAGRAM WYE DELTA 203EWD546 REF DRAWING...
Страница 50: ...13 11 602 Page 40 FIGURE 4 12 AUTO SENTRY ES CONTROLLER DISPLAY...
Страница 53: ...13 11 602 Page 43 FIGURE 5 2 FLOW DIAGRAM AIR COOLED 202EWD797 B Ref Drawing...
Страница 54: ...13 11 602 Page 44 FIGURE 5 3 FLOW DIAGRAM WATER COOLED 203EWD797 A Ref Drawing...
Страница 68: ......
