Dual-Purpose Vacuum Breaker Valve for Gravity Drain Backflow Prevention
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Solution Overview
Problem
Existing valve systems in potable water and drain systems face challenges in preventing cross-contamination and backflow, especially in scenarios where an air gap is impractical, and require a solution that can operate without line pressure.
Innovation Solution
A dual-purpose valve assembly comprising a vacuum breaker valve and a check valve, with a flapper and a ball-and-O-ring mechanism, that allows for backflow prevention and operates under gravity, preventing cross-contamination by sealing the flow between the supply and drain lines.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a backflow preventer with vacuum breaker function is used instead of an air gap, then space requirements are reduced and installation flexibility is improved, but the risk of cross-contamination increases
Solution Approach 1:
The patent combines two separate valve functions (vacuum breaker and backflow preventer) into a single integrated valve assembly. The vacuum breaker portion includes a flapper valve that opens to admit air when vacuum occurs, while the backflow preventer portion includes a check valve with ball and seat that prevents reverse flow. This merging allows the device to provide both protective functions in one compact unit, reducing space requirements while maintaining cross-contamination prevention through the combined action of both valve mechanisms.
Solution Approach 2:
The patent introduces an intermediary air admission mechanism (flapper valve) that mediates between the potable water system and the atmosphere. When vacuum pressure occurs, the flapper opens to allow air entry, breaking the vacuum without allowing backflow. The check valve with ball and seat acts as an intermediary barrier that physically blocks reverse flow while allowing forward flow. These intermediary elements protect the system from cross-contamination while enabling the reduced-space configuration.
2Reliability
If traditional valve systems are used to prevent backflow and vacuum conditions, then protection is provided, but the system requires line pressure to operate
Solution Approach 1:
The valve assembly is designed to operate automatically using the natural pressure differential and gravity without requiring external line pressure or power sources. The flapper valve responds automatically to vacuum conditions by opening to admit air, while the check valve with ball and seat automatically responds to backflow conditions by closing the passage. The weights of the components and the pressure differential provide the operating force, making the system self-service and eliminating the need for additional line pressure requirements.
Solution Approach 2:
The check valve mechanism uses the weight of the ball as a counterbalance to the backflow pressure. The ball rests on the valve seat under normal conditions, and backflow pressure must overcome the ball's weight to open the valve. This anti-weight mechanism provides reliable backflow protection without requiring additional line pressure, as the gravitational force on the ball provides the necessary closing force.
3Object-affected harmful factors
If separate drain lines are maintained to prevent cross-contamination, then water quality is protected, but space and drainage slope requirements are limited
Solution Approach 1:
The patent enables the merging of separate potable water and greywater drain lines by placing the dual-function valve assembly at the intersection point. The valve assembly maintains separate flow paths for the two drain lines while preventing cross-contamination through its backflow prevention mechanism. This allows the drain lines to be combined in space-constrained environments without sacrificing water quality protection, significantly improving installation flexibility and adaptability to various spatial configurations.
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 dual-purpose valve assembly effectively prevents backflow and cross-contamination, ensuring the safe drainage of potable water systems without the need for an air gap or line pressure, while maintaining the integrity of both fresh and grey water systems.
Implementation Method 1
the vacuum breaker valve may be a flapper... The flapper may be disposed in the vacuum breaker cavity between the first port and the third port
Implementation Method 2
The second valve may comprise a ball and an O-ring, the ball being configured to float, contact, and create a seal with the O-ring
Implementation Method 3
the ball being configured to float, contact, and create a seal with the O-ring when the second valve is in the second closed position
Implementation Method 4
The drain system may be configured to operate on gravity from a draining fluid
Data Source
AI summary
A dual purpose valve assembly may comprise a conduit, a first valve, and a second valve. The first valve may comprise a vacuum breaker valve. The second valve may comprise a check valve. A drain system may comprise a supply tube, a drain tube, and a dual purpose valve disposed between the supply tube and the drain tube. The drain system may allow fluid to drain based on gravity alone, and the dual purpose valve assembly may operate based on gravity alone.