Condensing pressure regulator: Used to maintain a constant and sufficiently high condenser – and receiver pressure in refrigeration and air conditioning plants with air-cooled condensers. Evaporating pressure regulator: To be mounted in the suction line after the evaporator. Used to maintain a constant evaporating pressure and thereby a constant surface temperature on the evaporator. Also, regulators protect against too low an evaporating pressure. The regulator closes when the pressure in the evaporator falls below the set value. Crankshaft pressure regulator: To be fitted in the suction line ahead of the compressor. Protects the compressor motor against overload during start-up after long standstill periods or after defrost periods.