Pressure Reducing Landing Valve
A pressure regulator is a valve that controls the pressure of a fluid or gas to a desired value. Regulators are used for gases and liquids, and can be an integral device with a pressure setting, a restrictor and a sensor all in the one body, or consist of a separate pressure sensor, controller and flow valve.
Two types are found: The pressure reduction regulator and the back-pressure regulator.
A pressure reducing regulator is a control valve that reduces the input pressure of a fluid or gases to a desired value at its output. It is a normally-open valve and is installed upstream of pressure sensitive equipment.
A back-pressure regulator back-pressure valve, pressure sustaining valve or pressure sustaining regulator is a control valve that maintains the set pressure at its inlet side by opening to allow flow when the inlet pressure exceeds the set value. It differs from an over-pressure relief valve in that the over-pressure valve is only intended to open when the contained pressure is excessive, and it is not required to keep upstream pressure constant. They differ from pressure reducing regulators in that the pressure reducing regulator controls downstream pressure and is insensitive to upstream pressure.