Diaphragm Insert Bleed Passageways With Self-Cleaning Wiping Action
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Pilot operated water valves are prone to bleed hole clogs due to contaminants, which can lead to valve malfunction, despite the use of multiple bleed holes and design features like tapered slots and scallops, as contaminants can still accumulate and cause clogs.
Innovation Solution
The implementation of self-cleaning water passageways in pilot operated water valves, featuring tapered bleed slots and an unrolling diaphragm with a wiping action, which dislodge and flush out contaminants from the bleed holes and slots during the opening and closing cycles, ensuring continuous operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple bleed holes are used, then the reliability is improved by reducing clog risk, but the manufacturing precision is worsened due to increased complexity of creating multiple precise holes
Solution Approach 1:
The single bleed hole is segmented into multiple bleed holes (first and second bleed holes) positioned at different locations on the diaphragm insert. This segmentation allows water to flow through multiple separate paths, reducing the likelihood that all paths will be blocked simultaneously by contaminants, thereby improving reliability while maintaining manufacturability through standardized multi-hole patterning processes.
Solution Approach 2:
The bleed holes are positioned at different angular positions (e.g., 180 degrees apart) around the central axis of the diaphragm insert, utilizing the radial dimension. This spatial distribution in multiple dimensions ensures that contaminants blocking one hole are unlikely to block others, improving reliability without significantly increasing manufacturing complexity.
2Reliability
If bleed holes are made larger, then the reliability is improved by reducing clog susceptibility, but the manufacturing precision is worsened due to difficulty in maintaining precise dimensions
Solution Approach 1:
Different regions of the diaphragm insert have different hole size characteristics. The bleed holes are positioned at specific radial distances from the center, with each hole optimized for its local flow requirements. This local optimization allows larger hole diameters at positions where flow capacity is needed, while maintaining precise positioning through localized manufacturing processes.
Solution Approach 2:
The hole diameter parameter is increased for the bleed holes compared to traditional designs, changing the physical parameter to reduce clog susceptibility. This parameter change is compensated by precise control of hole positioning and orientation, maintaining manufacturing precision through adjusted process parameters rather than reducing hole size tolerances.
3Manufacturing precision
If the diaphragm is made rigid for stability, then the manufacturing precision is improved, but the ease of operation is worsened due to inability to self-clean passageways
Solution Approach 1:
The diaphragm insert is designed with asymmetric geometry including tapered sides that create differential forces during operation. When water pressure increases, the diaphragm dynamically shifts position, causing the tapered surfaces to scrape against the valve body bore, providing self-cleaning action. This dynamic movement is built into the rigid structure through its geometric design rather than requiring flexibility.
Solution Approach 2:
The self-cleaning action occurs periodically during each valve operation cycle. As the valve opens and closes, the diaphragm repeatedly contacts and scrapes against the valve body bore, creating periodic cleaning action that removes accumulated contaminants. This periodic mechanical cleaning is integrated into the normal operational cycles of the valve.
4Ease of operation
If tapered bleed slots are used, then the ease of operation is improved by creating self-cleaning flow, but the manufacturing precision is worsened due to difficulty in creating precise tapered geometries
Solution Approach 1:
The bleed slots are designed with specific taper angles and ratios that optimize the self-cleaning flow pattern. By carefully selecting and controlling the taper parameter within a defined range, the design achieves effective contaminant flushing while remaining manufacturable using standard precision machining processes. The parameter is optimized to balance cleaning effectiveness with manufacturing capability.
Solution Approach 2:
The tapered geometry is applied locally to specific regions of the bleed slots rather than uniformly throughout. The taper is concentrated at the entrance or exit regions where it most effectively generates cleaning flow, while other portions maintain simpler geometries that are easier to manufacture with high precision. This localized application of complexity reduces overall manufacturing difficulty.
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 self-cleaning mechanism effectively reduces the likelihood of bleed hole clogs, maintaining the valve's functionality even in the presence of contaminants, by utilizing the increased water flow force through tapered slots and the unrolling and wiping actions to clear debris.
Implementation Method 1
The increasing taper of the bleed slot allows in-rushing water to accelerate as it moves towards the narrower top of the bleed slot. This increases the force with which the water exits through a bleed hole, causing the water to flush out any contaminants that may have become stuck in the bleed hole.
Implementation Method 2
The unrolling feature of the diaphragm creates a two-step cleaning process... The second cleaning step is a wiping action during the valve closing process. Once the armature is deactivated, the pilot passageway is closed and water flows through the passageways between the diaphragm and insert again clears away any contaminants in the passageway.
Data Source
AI summary
A valve is disclosed a valving member positioned in an internal valving cavity and operable to control a flow of water therethrough. The valving member includes a diaphragm and an insert. A passageway through the diaphragm communicates with a bleed slot, preferably a tapered bleed slot, and a scallop of the insert. The scallop cooperates with the diaphragm to form a bleed holes when the valving member is in a closed position. The diaphragm and the insert at least partially separate when the valving member is opened to expose the bleed slot and scallop. The diaphragm rolls up to contact the insert when the valving member is closed to create a wiping action to flush any trapped debris from the bleed slot.