13-21-615 v01 Page 66
WATER FLOW CONTROL VALVE FOR HEAT EXCHANGER (Optional Equipment)
(Figure 5-10, page
65) The water flow control valve is adjustable to compensate for varying water inlet temperatures and
pressures and is to be mounted in the water outlet line after the oil cooler (Figure 5-3, page 54). Use the
compressor discharge air temperature gauge on the instrument panel in setting the flow control valve. The
compressor discharge temperature must be maintained a minimum of 10
F (5
C) above the dew point
temperature at the maximum anticipated ambient; refer to
Figure 5-1
& 5-2, for the dew point temperature
at the operating pressure and ambient temperature of the application.
To decrease water flow
(increase compressor discharge air temperature) turn the adjusting screw from
left to right, increasing spring tension.
To increase water flow
(decrease compressor discharge air
temperature) 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 obtaining 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 a 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 valve malfunctions, check for bent or binding, paint or corrosion on valve stem, foreign material in valve,
erosion, or thermal system (capillary) failure. If foreign material or scale is likely, the use of a strainer in the
inlet water line is recommended.
