Answer:
There are 6 types of pressure control valves and their function is to regulate the pressure below a threshold level within safe limits and to maintain and control pressure of a particular circuit.
Step-by-step explanation:
The six type of Pressure valve with their functions are given below:
a. Unloading Valve:
These type of pressure valve are used to pour fluid into the container at very low or no pressure.
b. Safety valve:
These are used when the pressure within the vessel is in excess as inside temperature is near about preset [point point then these valves are open to release the extra pressure and are closed once normal conditions are regained.
c. Pressure Reducing Valve:
These are basically used for the control of the pressure in downstream not exceeding the design limits.
d. Pressure Relief Valves:
These are basically used to limit and regulate the pressure of any system.
e. Counter Balance Valve:
These are used to develop pressure in the reverse direction at the actuator's return line in order to keep the load under control.
f. Sequence Valve:
These are used to maintain sequence or order in the operations of two parts or branches.