The 2″ Float Vent Valve is installed in the Model 510 Extractor Vent Valve Assembly to help prevent product mixing in manifolded underground tank lines. The valve also serves as an overfill protection device, that complies with the EPA’s 90% capacity fill restriction. When product reaches a predetermined level during UST filling, the ball float rises and seats tightly against a specially designed valve seat. This will restrict the vapor flow back to the transport tanker, creating pressure in the UST which substantially reduces the product drop flow and signals the attendant to stop filling the UST. The Valve features a rust resistant epoxy coated steel body, brass cage, stainless steel ball float and is available with 1/8″ or 1/16″ bleed holes.