For stepless (infinitely variable) capacity control of air compressors: Suction control valves, bypass valves, bleed valves and engine speed controllers are governed by the signal from the proportional controller.
Controllers P22 are negative acting. Within the control band (see diagram 2) they give a proportionally rising signal at (A) on increasing pressure at (E).
The set point is adjusted by turning the hand wheel.
* To a higher pressure: clockwise.
* To a lower pressure: counterclockwise.
Type, nozzle（0.8, 1.0, 1.2, 1.5, 1.6, 2.0）
Proportional band (control band):
Increase: install an outlet nozzle with larger diameter.
Decrease: install an outlet nozzle with smaller diameter.
Control signal of P22