Pressure regulators reduce a supply pressure to a lower outlet pressure and they maintain this outlet pressure regardless of inlet pressure fluctuations. This reduction in pressure is the key characteristic of pressure regulators; outlet pressure is always at a pressure below the inlet pressure.
Operating Pressures: The inlet and outlet pressures are important factors to consider before choosing the best regulator. Important questions to answer are: What is the range of fluctuation in the inlet pressure? What is the required outlet pressure? What is the allowable variation in outlet pressure?
Flow Requirements: What is the maximum flow rate that the application requires? How much does the flow rate vary? Porting requirements are also an important consideration.