Liquid Control Valve Diaphragm Distortion Prevention
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Solution Overview
Problem
Liquid pressure control valves with flexible members, such as diaphragms, face issues with excessive closing pressure causing distortion or fracture, and the use of rigid backing elements can impede fluid flow.
Innovation Solution
A valve design incorporating a flexible member with a controlled bleed passage and a slide mechanism that limits closing displacement, featuring a stop to prevent further closure and maintain flow efficiency, along with an actuating arm and pivotally mounted pin with complementary seals to manage pressure and flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a rigid backing element (metal plate) is provided to prevent excessive displacement or distortion of the flexible member, then the reliability of the flexible member is improved, but the liquid flow through the valve is impeded
Solution Approach 1:
The patent uses a thin slide made of flexible material (such as a thin wall tube or flexible membrane) instead of a rigid metal plate. This flexible slide is coupled to the flexible member and moves with it, providing distortion limitation while allowing liquid to flow through the thin wall structure without significant impediment.
Solution Approach 2:
The slide acts as an intermediary element between the flexible member and the valve seat. It is coupled to the flexible member surrounding the seal area and provides the limiting function, while its thin, flexible nature allows it to present minimal resistance to liquid flow compared to a solid rigid plate.
2Reliability
If the flexible member is allowed to displace fully to close the valve, then the sealing capability is improved, but the flexible member may collapse or distort under excessive closing pressure
Solution Approach 1:
The slide provides preliminary protection against excessive displacement by acting as a mechanical stop. When the flexible member displaces to close the valve, the slide moves with it and is limited by a stop, preventing the flexible member from collapsing or fracturing under excessive closing pressure while still allowing sufficient displacement for sealing.
Solution Approach 2:
The combination of the slide and stop provides a cushioning effect before excessive displacement occurs. The slide moves with the flexible member during normal operation and sealing, then the stop engages to prevent further displacement, cushioning against the harmful effects of excessive closing pressure before damage can occur.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively limits distortion and maintains flow efficiency by preventing excessive closure while ensuring the valve can operate without impeding liquid flow, thus providing a reliable and efficient pressure control mechanism.
Implementation Method 1
a controlled bleed passage joining the inlet to the chamber, other than in an open mode of the valve, whereby inlet pressure in the chamber will displace the flexible member toward a closed mode
Implementation Method 2
a slide is mounted within the cavity and is coupled to a section of the flexible member surrounding the seal thereof as to be displaced with displacement of the flexible member, and a stop to prevent closing displacement of the slide after the has seated over the inlet port
Implementation Method 3
a pin including a pair of longitudinally spaced apart grooves mounted in the bleed passage with the bleed passage including a pair of complementary longitudinally spaced apart seals to seal against the pin
Data Source
AI summary
A float or a near neutral buoyancy weight operated liquid pressure control valve includes a body which together with an end cap form a cavity and retain a diaphragm therein. A back-pressure chamber is formed between the end cap and the diaphragm and the diaphragm includes a seal section which seats on an inlet port. The diaphragm seal also separates the inlet from an outlet formed in the body. A float support arm reciprocally operates a valve opening and closing control pin mounted in an associated bleed passage formed longitudinally through a control pin mounting. In an open mode the bleed passage vents the chamber. In a closed mode the pressure in the chamber displaces the diaphragm to close the valve. A slide is coupled to the diaphragm so as to be displaced therewith and prevent excessive pressure to distort the diaphragm once the seal closes on port.