초록 ▼

A butterfly valve has a valve body with an improved seal assembly mounted in the groove about a flow passage in the valve body. The seal assembly has an outer metal body including a pair of spaced inner legs having outer ends thereof in sealing contact with the outer periphery of a valve disc in the

A butterfly valve has a valve body with an improved seal assembly mounted in the groove about a flow passage in the valve body. The seal assembly has an outer metal body including a pair of spaced inner legs having outer ends thereof in sealing contact with the outer periphery of a valve disc in the closed position of the valve disc to provide a pair of spaced metal sealing surfaces with the outer periphery of the disc. An elastomeric face seal is positioned between the two spaced inner legs in sealing contact between the spaced metal sealing surfaces with the outer peripheral sealing surface of the valve disc at low pressures. An upstream inner leg is urged inwardly toward the downstream inner leg to space the upstream leg from the adjacent surface defining the groove and permit the upstream pressure to be exposed between the inner and outer upstream resilient legs thereby to urge the upstream leg tightly into contact with the adjacent peripheral sealing surface of the valve disc in the closed position thereof. The outer resilient legs are seated in the bottom of the groove to provide a substantially fluid-tight contact with the adjacent surfaces of the groove, and the inner legs are urged upon contact with the valve disc away from the valve disc toward the outer seated legs thereby to load the seal assembly with a predetermined preload pressure. Fluid is prevented by the outer legs from flowing behind the seal assembly.

대표청구항 ▼

In a butterfly valve having a valve body with a flow passage therethrough, an annular groove in the body about the flow passage, and a valve disc mounted in the flow passage for movement between open and closed positions relative to the flow passage; an improved seal assembly mounted in said groove

In a butterfly valve having a valve body with a flow passage therethrough, an annular groove in the body about the flow passage, and a valve disc mounted in the flow passage for movement between open and closed positions relative to the flow passage; an improved seal assembly mounted in said groove for sealing against the outer periphery of the valve disc in the closed position thereof, said seal assembly comprising a metallic body and an elastomeric face seal; said metallic body including a pair of outer resilient legs having outer ends contacting the bottom of the groove and a pair of spaced inner legs having outer ends contacting the outer periphery of the valve disc in the closed position of the valve disc to provide metal-to-metal sealing contact with the outer periphery of the disc along two spaced metallic sealing surfaces formed by the ends of the inner legs, said elastomeric face seal being positioned between the spaced inner legs and contacting the disc sealing surface in the closed position of the disc to provide sealing contact with the outer periphery of the disc along a sealing surface between the spaced metallic sealing surfaces; said resilient inner legs and said elastomeric face seal being deflected outwardly relative to said resilient outer legs upon engagement of said disc with the inner legs and face seal in the closed position thereby to bias the seal assembly against the valve disc for establishing the three aforementioned sealing surfaces between the seal assembly and the outer periphery of the valve disc in the closed position of the valve disc.