Pressure Regulating Valve or commonly abbreviated to PRV is a component of hydraulic or pneumatic system that serves to adjust the fluid pressure of the high pressure system resources (such as pumps, compressors, or reservoir) to the low-pressure system. PRV is always in charge of maintaining fluid pressure value is lower than its supply pressure, therefore the pressure of the fluid before passing the PRV will always be greater than the pressure after passing through PRV. It can be said PRV serves to lower fluid pressure so that it meets system requirements specification, or also for the security and safety of use.
Broadly speaking there are two types of PRV when seen from operational systems, namely single stage and two-stage pressure regulator. The above picture illustrates a PRV system with only a single stage pressure regulator. The image appears on several major components such PRV inlet and outlet pressure gauge, diaphragm membrane, spring, poppet valve, as well as a lever to adjust the set point PRV working pressure. Pressure gauge serves as a good appointment fluid pressure value on the source side and the output side pressure of the PRV. Diaphragm function is to create a flexible working space in the PRV capable of changing volume. Two springs on the PRV system serves to generate pressure equilibrium, while Poppet valve serves to open and close the fluid flow.
The most fundamental difference of PRV with a two-stage pressure regulator as compared to the previous system is the two-stage system was used spring and diaphragm membrane that is more to create an equilibrium in the PRV chamber (chamber). At the time of the fluid pressure in the outlet room to fall, then spring 1 will suppress the diaphragm and poppet valve 1 so that a higher pressure fluid in the chamber will go into the outlet chamber. When the fluid pressure chamber drops because they have got into the room outlet, then the same process occurs in the spring 4 which will encourage the poppet valve 2 so that a higher pressure fluid went into the chamber. When the fluid pressure outlet is in conformity with the pressure set point was, the spring system will form an equilibrium so that both poppet valve will be fully closed.