Water dispensers high and low pressure switch 27 LF42 series pressure switch is used in water supply pressure protection of water inlet. This series include two models LF42H(high pressure protection) and LF42L(low pressure protection). LF42H is the high pressure protection switch model. If the pressure of the pressure vessel transferred reaches the setting value while the vessel is full filled with water, the switch will cut off the circuit to make the pump stop. So the pump will not be damaged. LF42L is the low pressure protection switch. If the pressure of water inlet lower than set value, RO will not work and keep dewatering, then the switch will cut off the circuit to make the pump stop. It can prevent the booster pump still working without water which may lead to the damage of the circuit. If the pressure of the water inlet returns to the lowest set volume, the pump will work again. Dimension in:mm Specification Model Proof pressure Working temperature Switch type Microswitch , normal close Microswitch , normal open Electrical rating 4.8*0.8 blade A quarter fast interface A quarter fast interface