The KVP is mounted in the suction line after the evaporator and is used to:
- Maintain a constant evaporating pressure and thereby a constant surface temperature on the evaporator. The regulation is modulating. By throttling in the suction line, the amount of refrigerant gas is matched to the evaporator load.
- Protect against an evaporating pressure that is too low (e.g. as protection against freezing in a water chiller). The regulator closes when the pressure in the evaporator falls below the set value.
- Differentiate between the evaporating pressures in two or more evaporators in systems with one compressor