Gardner Denver VST110 Operating And Service Manual page 57

Adjustments – The regulator valve shall be adjusted so that it closes when the cooling water entering
and exiting the package are at the same temperature – a condition that is present after the compressors
have stopped and the heat exchangers have cooled down. This adjustment mode will prevent the
circulation of cooling water when it is not needed. Adjustment to the regulator valve can be made as
follows:
·
To decrease water flow (e.g., increase exiting cooling water temperature) turn the adjusting screw
from left to right, increasing spring tension.
·
To increase water flow (e.g., decrease exiting cooling water temperature) turn the adjusting screw
from right to left, decreasing spring tension. 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.
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 with 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, 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 a bend or binding in the capillary tube, paint or corrosion on valve
stem, foreign material in valve, erosion or thermal system (capillary) failure.
Water Flow Shutoff Valve (Optional Hardware) - This device completely shuts off the flow of cooling
water when the compressors are not operating. Its normally closed state prevents the waste of cooling
water even in the case of power failure. It is a common companion to the water flow regulating valve.
The water flow regulating valve and the water shutoff valve are factory-installed options. If the presence
of foreign material or scale formation in the cooling water is likely, the use of a strainer in the inlet water
line is recommended.
Figure 6-4 – WATER CONTROL VALVE
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