Gardner Denver EAH99C Operating And Service Manual page 34

COMPRESSOR CAPACITY CONTROL - TURN VALVE UNITS ONLY
The capacity of the compressor is controlled by the action of the turn valve and the compressor inlet
valve.
The turn valve controls compressor delivery to match demands of 40% to 100% of the compressor's
maximum capacity. The inlet valve throttles to control compressor delivery to match demands of 0% to
40% of the compressors maximum capacity.
Example with normal setting of 100 PSIG:
Compressor Delivery
Capacity
Full
70%
40%
30%
20%
0%
Inlet Valve
Open
Open
Open
Closing
Closing
Closed
13-9-663
Turn Valve
Closed
50% Open
Full Open
Full Open
Full Open
Full Open
Page 33
Discharge Manifold
Pressure
100
100
100
103
103
103