The Mist Auto Drain Valve is an essential component for any outdoor mist cooling system. It is designed for installation in one of two ways: either thread it into a 10/24 female-threaded nozzle opening or insert it into any professional Slip-Lok fitting. The auto drain valve is used to drain water from the mist line when it is not in use. It operates as a siphon by drawing the water out of the system once it is no longer pressurized. When.. See full description for further details