Page 80 - PNEUMATIC SYSTEM INSTRUMENT

Table 10.2: Standard symbol and function of pressure control valve

Type Standard symbol and function

Pressure Fixed pressure Adjustable Reversed
valve pressure valve pressure valve.
regulating

valves
Function:

The pressure regulating valve controls the operating

pressure in a control circuit and keeps the pressure constant

irrespective of any pressure fluctuations in the system.

Pressure
Fixed limiting
limiting Adjustable
valve limiting valve
valves with
Function:
relief port
The pressure limiting valves are utilized on the up-stream

side of the compressor to ensure the receiver pressure is

limited, for safety, and that the supply pressure to the system

is set to the correct pressure.

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