The Jobe Valves Vortex Part Fill Valve is a high-flow valve intended for use in rain water harvesting tanks. The purpose of the float valve is to automatically maintain a low level of water in the tank during periods of no or low rainfall. This allows services fed by the tank to continue while leaving capacity in the tank for refilling by the next rain. The high-flow valve's body is constructed from non-corroding materials for durability and to ensure no particles get in your water. The part fill valve's body unscrews from tail for easy valve access.