초록 ▼

A dual check valve backflow prevention apparatus of lightweight, compact construction which provides low flow losses and which maintains a small positive pressure differential under static flow conditions via use of a magnetic valve closure mechanism. The apparatus comprises a main valve housing whi

A dual check valve backflow prevention apparatus of lightweight, compact construction which provides low flow losses and which maintains a small positive pressure differential under static flow conditions via use of a magnetic valve closure mechanism. The apparatus comprises a main valve housing which contains two check valve assemblies. Each check valve assembly has a clapper valve which uses a low friction magnetic pull closure force and drip tight seals in the forward flow direction for maintaining a small positive pressure differential under static conditions. The magnetic bias for the closure force is preferably located in the center of the flow stream. An additional closure force may be provided by a spring or gravity assistance.

대표청구항 ▼

[ What is claimed is:] [1.] A backflow prevention apparatus, comprising:(a) a valve housing, said valve housing having a flow stream;(b) at least one check valve assembly, said check valve assembly comprising a clapper and a seat, said check valve assembly positioned within said valve housing in sai

[ What is claimed is:] [1.] A backflow prevention apparatus, comprising:(a) a valve housing, said valve housing having a flow stream;(b) at least one check valve assembly, said check valve assembly comprising a clapper and a seat, said check valve assembly positioned within said valve housing in said flow stream;(c) said check valve assembly including a first magnet centrally mounted on said clapper and a second magnet centrally mounted on said seat, said first and second magnets centrally located in said flow stream; and(d) drip tight means, associated with said check valve assembly, for maintaining a small positive pressure differential under static conditions.