Diaphragm valve with improved sealing performance and leak detection

Abstract

Diaphragm valve with internal leak detection and improved external leak sealing performance. In diaphragm valves comprising diaphragms that have shields and backings, a rigid seal plate interposed between the shield and backing prevents peripheral regions of the shield from cold-flowing into the backing, despite the compression forces produced by tightening the fasteners that secure the diaphragm to the valve's bonnet assembly and body. An access port passing through the seal plate provides an interface between a void located between the shield and the backing and a breach detector. The breach detector is configured to detect pressure, volume, moisture or mass deviations in fluid disposed in the void, and the deviations indicate whether there's a rupture in the shield or the backing. The breach detector can be connected to an alarming device or signaling system to provide warnings and alerts to valve operators, process control panels or data communications networks.

Description

technical field [0001] Embodiments of the present invention generally relate to two-plate diaphragm valves commonly used as flow control or shutoff valves in various process applications and industries, including but not limited to food and beverage, pharmaceutical, and bioengineering. More particularly, the present invention relates to methods and apparatus for preventing and detecting leaks, ruptures or other diaphragm failures in such two-petal diaphragm valves. Background technique [0002] Diaphragm valves (or membrane valves) are commonly used to start, stop, and / or control the flow of process fluids (eg, gases, liquids, or slurries) through process systems, or to create or control vacuum spaces in process systems. In general, a diaphragm valve consists of a valve body with an internal flow path between two or more ports, a flexible diaphragm, a compressor that pushes and stretches the flexible diaphragm across the internal flow path, and a "saddle" or The "seat", the...

AI Technical Summary

Problems solved by technology

[0012] However, none of these proposals addresses the aforementioned problem of external leakage due to certain areas of the shroud deforming inwardly into the liner, or without disassembly, re-sterilization and / or replacement of valve components. Detect shroud breaches or potential breaches

As a result, the use of traditional two-piece diaphragm valves in sensitive and aseptic processing operations remains an expensive and time-consuming proposition, both because of the high incidence of external leakage due to inward deformation of the shield into the liner, and because of the Relatively frequent loss of time and productivity as traditional two-petal diaphragm valves are taken out of service for inspections needed to detect and prevent shield failure