초록 ▼

A horizontal check valve has a swinging clapper (16) eccentric with a tapered valve seat (14) and carrying a floating ring seal. There is clearance between the clapper (16) and the passage wall at the bottom so that reverse flow urges the ring seal into the taper. The clapper (16) abuts an abutment

A horizontal check valve has a swinging clapper (16) eccentric with a tapered valve seat (14) and carrying a floating ring seal. There is clearance between the clapper (16) and the passage wall at the bottom so that reverse flow urges the ring seal into the taper. The clapper (16) abuts an abutment surface (15) formed by the valve body (10) around the valve seat so that the hydrostatic forces exerted on the clapper (16) by the reverse fluid flow are reacted by the abutment surface and not by the tapered seat (14).

대표청구항 ▼

A check valve comprising a housing which forms a through passage which is to be connected into a fluid pipeline when the valve is in use, the housing including an annular valve seat which extends around the passage and tapers towards the upstream end of the passage in the context of the normal direc

A check valve comprising a housing which forms a through passage which is to be connected into a fluid pipeline when the valve is in use, the housing including an annular valve seat which extends around the passage and tapers towards the upstream end of the passage in the context of the normal direction of flow through the passage, and an obturating member cooperable with the valve seat to close the through passage and displacable from the valve seat to allow fluid flow through the through passage, the obturating member carrying an annular seal which effects a seal between the obturating member and the valve seat when the through passage is closed by the obturating member, wherein the annular seal comprises a floating ring seal, and an abutment surface extends around at least part of the passage downstream of the valve seat, the obturating member being adapted to make direct face-to-face contact with the abutment surface when it closes the through passage and being formed to provide for access to the annular seal for reverse fluid flow when the passage is closed by the obturating member, the obturating member, abutment surface, valve seat and annular seal being arranged such that the housing reacts a load exerted on it through and by the obturating member without that load being applied to the annular seal such that, once initial contact of the seal with the valve seat is established, fluid tight contact between the seal and the valve seat and the obturating member is established solely by the action of fluid pressure on the seal.