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13-17-609 Page 53
5-8
OIL FLOW CONTROL VALVES
- These devices feed a regulated amount of oil into various areas of the
1st stage compressor and inter-stage manifold. Each of three (3) normally open solenoid valves is paired
with one or more in-line orifices to deliver distinct oil flows. When used in combination with a permanently
open injection line, the system provides five (5) distinct oil flow regimes - a summary of the logical steps
controlling the opening and closing of these valves is shown on the footnotes of Figure 4-3, page 35.
The aim of the stepped oil flow modulation is to maintain optimal 1st and 2nd stage compressor discharge
temperatures (between 195
°
F and 220
°
F). The AirSmart controller governs the oil flow control valve
operations
– refer to AirSmart Manual 13-17-600 for detailed information on programmed operations of
these valves.
The
“energized” state of each valve is visually confirmed by a light emitting diode (LED), housed within
the (transparent) electrical plug termination of the cable connected to the valve coil. This information,
when used in conjunction with the matching sequence of outputs listed in the AirSmart Manual 13-17-600,
will help verify the proper operation of each valve. In case a solenoid valve malfunction is detected (e.g.,
correct controller output plus LED confirmation, but the valve will not react), the best course of action is to
replace the complete valve.
Figure 5-4 – PRESSURE DEW POINT OF COMPRESSED AIR
LOW AIR DEMAND AND PACKAGE OPERATION
– During periods of very low air demand, such as
when the package is operated in short cycles, the oil system may not reach a high enough temperature to
keep water vapor from condensing, in spite of the oil mixing valve bypassing oil flow around the heat
exchanger.
Under these conditions, it is recommended that the package operation be prolonged after each unload
condition is achieved
– this can be easily accomplished by adjusting the “Auto Timer” option in the
AirSmart controller. Refer to the AirSmart control user
’s manual 13-17-600 for detailed programming
instructions of this parameter and adjust the
“Auto Timer” parameter to a value of at least 5 minutes.
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Discharge PDP
-°
F
Ambient Temp - °F
Pressure Dew Point Trend
100psig
125psig
150psig
175psig