Ball float valves or check valve is a device that interrupts the flow of liquid product being dispensed at a fuel depot to tanker trucks.
These valves have a two-state function. It is either open or closed. When the floating ball exceeds the diameter of a dispensing hose the fluid is blocked and stops.
Stage II vapor recovery systems in fuel depots incorporate the of use float valves.
Vapor recovery systems are in place to reduce product loss in tanks and dispensing points.
The environmental and fiscal concerns about product loss due to evaporation are very real. It is estimated that 147 million gallons of gasoline are lost each year due to evaporation. Source: EPA