초록 ▼

Disclosed is a fire-tested butterfly valve having a resilient flexible seat member held in place in a valve housing by being clamped between cooperating surfaces of the valve housing and a valve seat retaining ring insert. Also positioned between the housing and the insert is a fusible washer means

Disclosed is a fire-tested butterfly valve having a resilient flexible seat member held in place in a valve housing by being clamped between cooperating surfaces of the valve housing and a valve seat retaining ring insert. Also positioned between the housing and the insert is a fusible washer means which has a lower destruction temperature than that of the annular flexible seat. Further, the insert is spring biased toward the fusible washer and valve housing so that when the valve is exposed to fire the fusible washer melts, the insert is biased toward the housing, and as the annular flexible seat is destroyed by heat, an edge of the insert into contact with the butterfly disc to establish a secondary, metal-to-metal, fire resistant seal.

대표청구항 ▼

A butterfly valve comprising a housing defining a fluid flow channel, a shaft, a butterfly valve disc mounted on said shaft for rotation within said channel to control fluid flow therethrough, an annular resilient seat member circumscribing said channel to sealingly cooperate with the edge of said d

A butterfly valve comprising a housing defining a fluid flow channel, a shaft, a butterfly valve disc mounted on said shaft for rotation within said channel to control fluid flow therethrough, an annular resilient seat member circumscribing said channel to sealingly cooperate with the edge of said disc when said disc is perpendicular to said channel, a metal insert ring abutting said resilient seat and configured to provide a fulcrum against one side of said resilient seat, means for biasing said insert ring in sealing contact with said resilient seat, and fusible means positioned relative to said insert ring and spaced from said resilient seat to resist said biasing and hold the insert ring away from the valve disc to normally prevent metal-to-metal wear therebetween until exposure of the valve to fire destroys said fusible means, thereby permitting said insert ring to be biased toward said edge of said disc and contact same with secondary sealing means thereon to establish a metal-to-metal fire resistant seal.