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
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 damage to the circuit. If the pressure of the water inlet returns to the lowest set volume, the pump will work again.