Discharge Recycle Valve; Figure 2-6. Operational Diagram - Discharge Recycle Valve - Emerson Vilter PLC Operation Manual

Section 2 • Operational Descriptions

DISCHARGE RECYCLE VALVE

If installed, the discharge recycle valve is a motorized
or air actuated valve that recycles discharge gas back to
the suction of the blower package. The valve acts as a
regulator, opening to maintain the set pressure in the
discharge line.
A PID controller adjusts the opening degree of the valve
to maintain a desired pressure on the high pressure side
of the valve. When the recycle control pressure exceeds
the desired pressure plus a deadband, the valve will start
to open to recycle high pressure gas back to suction.
DISCHARGE
RECYCLE
SETTING
BLOWER
CONTROL
TARGET
100
0
2 – 10

Figure 2-6. Operational Diagram - Discharge Recycle Valve

Blower Package PLC Operation Manual •Vilter/Emerson • 35391BLP
DISCHARGE
PRESSURE
DISCHARGE
RECYCLE VALVE
POSITION (% OPEN)