Cooling Water: General Considerations; Cooling Water: Flow And Pressure Requirements - HELIX 8200 Operating And Service Instructions

Installation

Cooling Water: General Considerations

Cooling Water: Flow and Pressure Requirements

3-4
NOTE: Adjust your water flow to maintain an optimum discharge water
temperature of 85°F with a minimum input pressure of 2 psig. For detailed
water requirements, see below.
1. Cooling water must meet flow and pressure requirements as
indicated in the following subsections.
2. Cooling water having a pH value of 6.0 to 8.0 and a calcium-car-
bonate concentration of less than 75 ppm, the quality of typical
municipal drinking water, is acceptable. If the cooling water has a
pH value lower than 6.0 or a calcium- carbonate concentration
higher than 75 ppm, water conditioning may be required.
3. To conserve water, the cooling water should be shut off when the
compressor is not running.
If cooling water below 45°F (7°C) is allowed to run through the
compressor while the compressor is not operating, the compressor oil
will change viscosity and thicken, causing the compressor to overheat
and shut off at startup. In this event, repeatedly restart the compressor
and allow it to run until it has shut off several times. The oil
temperature will rise and thereby allow continuous compressor
operation.
4. Drain and purge water from the compressor before shipping it back
to the factory or subjecting it to freezing conditions. Purge water
from the compressor by blowing compressed air, regulated to 30 to
40 psig (200 to 275 kPa) into the compressor output connection and
allowing water to exit from the water input connection.
If your water supply pressure falls below 2 psig due to back pressure,
the compressor will overheat and shut down.
Use the two graphs in Figure 3-3, to determine the minimum acceptable
cooling water supply pressure at different flow rates and temperatures.
CAUTION
CAUTION
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C TI CRYOGENICS
HELIX TECHNOLOGY CORPORATION
P/N 8040353