Nozzle check valve

Abstract

A nozzle check valve comprises a valve body (10) and a nozzle (20) centrally arranged within the upstream end of valve body (10), a fluid channel (90) is defined by the outer face of the nozzle (20) and the inner face of the valve body (10). A guide bush (60) is mounted on a nozzle axial extension (26) and an annular disc (30) comprising a disc sealing ring (31) connected to a central barrel (32,33) by a plurality of webs (34) is mounted on the guide bush (60) for axial movement of the annular disc (30) relative to the valve body to open and close the fluid channel (90). A spacer (80) is arranged on the nozzle axial extension (26) downstream of the guide bush (60) and a diffuser (40) is arranged on the downstream side of the spacer (80). A spring (50) between the annular disc (30) and thediffuser (40) urges the disc towards the valve closed position. The stroke of the valve, the maximum movement of the annular disc (30) from the valve closed position to the valve open position where the annular disc (30) is in contact with the upstream face of the diffuser (40), is determined by the axial length of the spacer (80). The centre of mass of the annular disc (30) is located along the central axis of the disc (30) at an axial position where the barrel (32) is in sliding contact with the guide bush (60).

Description

technical field [0001] The present invention relates to nozzle check valves. Check valves for gas and liquid media are used e.g. in gas and liquid pipelines to automatically stop reverse flow as quickly as possible without any actuation, thus preventing damage to equipment including water hammer, pumps, and Problems including mixing of pipeline liquids and gases. Nozzle check valves, sometimes called axial check valves, act faster than other types of check valves such as double plate check valves and swing check valves. The faster the valve can close when reverse flow begins, the less shock there will be when the fluid starting to flow back suddenly stops. Background technique [0002] The general principle of a nozzle check valve is to use a disc that moves axially in response to fluid flow in the normal flow direction against the closing force, usually a spring. When flow is shut off, the disc moves axially to seal and prevent reverse flow. The most common design of no...

AI Technical Summary

Problems solved by technology

For umbrella disc valves and valves with annular discs supported on leaf springs, this adjustment can only be made at the manufacturer's factory

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