Pipe Disconnector Shiftable Seat for Stronger High-Pressure Sealing
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Solution Overview
Problem
Existing system disconnectors for liquid systems face issues with leakage due to insufficient sealing power, particularly at high pressures, when using spring-biased backflow preventers, which are not permitted for disconnecting drinking water and heating systems without physical disconnection to the atmosphere.
Innovation Solution
A shiftable seat is introduced in the hollow space of the release valve body, which moves to a casing-fixed stop, allowing a smaller valve seat diameter with increased tightening power, maintaining force balance across pressure conditions and enhancing sealing effectiveness without reducing the effective area for middle pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a spring-biased backflow preventer is used to prevent liquid backflow, then backflow prevention function is provided, but leakage occurs due to insufficient sealing power especially at high pressures
Solution Approach 1:
The invention divides the backflow prevention function into two independent components: a mechanical backflow preventer with spring bias for normal operation, and a separate pressure-actuated release valve with piston mechanism for failure mode. This segmentation allows each component to be optimized independently - the mechanical preventer provides reliable normal operation while the release valve provides enhanced sealing and failure protection without compromising the other function.
Solution Approach 2:
The invention introduces a pressure-actuated release valve with piston as an intermediary mechanism between the upstream and downstream systems. This intermediary provides an additional sealing barrier that is activated by pressure differential, enhancing the overall sealing power and preventing leakage that could occur through the mechanical backflow preventer alone, especially at high pressures.
2Reliability
If the valve seat diameter is reduced to increase tightening power, then sealing effectiveness improves, but the force balance across pressure conditions is disrupted
Solution Approach 1:
The invention employs a pressure-actuated piston mechanism that dynamically adjusts the sealing force based on the pressure differential between upstream and downstream systems. When pressure differential increases, the piston is forced against the valve seat with greater force, automatically increasing tightening power to match operating conditions. This dynamic adjustment maintains force balance across varying pressure conditions while allowing for a smaller valve seat diameter.
Solution Approach 2:
The invention changes the sealing mechanism from a static spring-biased system to a dynamic pressure-actuated system where the sealing parameter (tightening force) varies with operating pressure. The piston area and pressure differential serve as controllable parameters that automatically adjust the sealing force, allowing reduced valve seat diameter while maintaining adequate sealing effectiveness across the full range of operating pressures.
3Device complexity
If a mechanical backflow preventer is used alone for disconnecting liquid systems, then simplicity is maintained, but it is not permitted for drinking water and heating system disconnection due to leakage risk
Solution Approach 1:
The invention segments the backflow prevention system into a primary mechanical preventer and a secondary pressure-actuated release valve, creating a layered protection approach. This segmentation allows the system to meet the stringent reliability requirements for drinking water and heating system disconnection by providing multiple independent sealing barriers, while maintaining relatively simple operation through automatic pressure-actuated activation of the release valve.
Solution Approach 2:
The invention implements beforehand cushioning by providing a redundant sealing system (the pressure-actuated release valve) that activates automatically upon detection of pressure differential indicating potential failure. This prior cushioning ensures that even if the primary mechanical backflow preventer fails, the secondary system provides immediate protection, making the overall system suitable for critical drinking water and heating system applications.
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 provides a compact arrangement with improved sealing power and effectiveness at both high and low inlet pressures, preventing backflow while ensuring the release valve functions correctly across varying pressures.
Implementation Method 1
the pressure difference between the inlet pressure and the middle pressure counteracts a spring biasing the release valve body in the opening direction
Implementation Method 2
a spring biasing the release valve body in the opening direction
Data Source
AI summary
A system disconnector for disconnecting an upstream liquid system providing an inlet pressure from a downstream liquid system by a release valve (34) in response to a pressure drop between the systems, includes an upstream backflow preventer (40), a downstream backflow preventer (64) and a release valve body piston (18) arranged between the backflow preventers (40, 64). A pressure difference between the inlet pressure and a middle pressure between the backflow preventers (40,64) counteracts a spring (60) biasing the release valve body in the opening direction, the release valve body (18) having an effective pressurized surface (d) smaller than the surface effective for the inlet pressure. A hollow space (74) defined by the release valve body is connected to the middle pressure (66). A shiftable seat (76) provided in hollow space (74), is movable with respect to the release valve body to a fixed stop (84) upstream of the valve seat (32).