Rotating Plug Fire Valve Reduces Friction and Weight
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Solution Overview
Problem
Current fire protection control valves, particularly dry pipe and deluge valves, are large and heavy due to the requirement for a 5.5:1 differential area ratio between air and water seats, leading to high friction losses and operational challenges, and they often rely on external power sources or complex mechanisms, making them inefficient and difficult to install.
Innovation Solution
A fire protection control valve design featuring an eccentric rotating plug with a dynamic seat, utilizing a torsion spring and axial piston linkage to maintain a seal with reduced tolerance and lower seating torque, allowing for a smaller valve body and operation independent of external power, with an integral actuator achieving a 5.5:1 differential pressure ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a 5.5:1 differential area ratio between air and water seats is used, then the valve can maintain proper differential pressure operation, but the valve body becomes excessively large and heavy
Solution Approach 1:
The patent applies asymmetry by positioning the pivot point offset from the center of the annular seat, creating an asymmetric swing path for the clapper. This allows the clapper to swing out of the waterway to reduce friction losses while maintaining the required 5.5:1 differential area ratio between air and water seats, thereby achieving proper differential pressure operation without requiring an excessively large valve body
Solution Approach 2:
The patent moves the clapper motion from a purely radial swing to a three-dimensional arc path by offsetting the pivot point. This dimensional change allows the clapper to clear the waterway more efficiently and reduces the required valve body size while maintaining the differential area ratio requirement
2Reliability
If a large air seat area is used to achieve 5.5:1 differential ratio, then proper pressure differential is maintained, but friction losses increase
Solution Approach 1:
The offset pivot point creates an asymmetric clapper swing path that allows the clapper to clear the waterway during operation. This reduces the friction loss between the clapper and water flow while maintaining the large air seat area required for the 5.5:1 differential ratio, thereby maintaining pressure differential without excessive friction losses
3Reliability
If a swing-type clapper design is used, then the valve can operate with differential pressure, but the valve body must be very large to accommodate the air seat
Solution Approach 1:
By offsetting the pivot point from the center of the annular seat, the clapper follows an asymmetric swing path that allows it to clear the waterway more effectively. This enables the valve to maintain the required 5.5:1 differential area ratio with a smaller overall valve body area, as the asymmetric motion optimizes the space utilization
4Reliability
If tight tolerances are used for plug and seat alignment, then sealing performance is improved, but manufacturing complexity increases
Solution Approach 1:
The patent employs a dynamic seat that can move axially to accommodate variations in plug position and wear. This dynamic adjustment capability maintains consistent sealing performance over time and across manufacturing tolerances, eliminating the need for extremely tight manufacturing tolerances while preserving reliable sealing
Solution Approach 2:
The wave spring mechanism changes the contact pressure parameter dynamically as the plug moves or wears. This self-adjusting pressure compensation maintains effective sealing across a range of plug positions and manufacturing variations, reducing the stringency of tolerance requirements
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 design reduces friction losses, allows for smaller valve sizes, and ensures reliable operation over variable pressure ranges, maintaining a leak-tight seal and efficient flow control without external power, addressing the size and operational inefficiencies of existing valves.
Implementation Method 1
a wave spring for sealing, which reduces tolerance requirements and operating torque
Implementation Method 2
an integral actuator with a 5.5:1 differential pressure ratio to maintain a leak-tight seal and facilitate efficient operation
Implementation Method 3
The design results in a smaller, lighter valve body with reduced friction losses and improved sealing performance
Data Source
AI summary
A differential dry pipe control valve for fire protection sprinkler systems includes an eccentric plug that rotates and separates supply water and system air pressure and uses an integral actuator that maintains the seal of the eccentric plug with a smaller ratio of air pressure to a higher supply water pressure. When the sprinkler system is actuated, the actuator allows the rotary eccentric plug to open the waterway and includes an eccentric plug opening that swings out of the waterway to reduce friction loss of the water supply. The eccentric plug includes a conical rubber coated seat surface and dynamic metal seal seat that seals due to water pressure eliminating close tolerance mating of sealing components. The actuator includes an integral alarm connection to provide a required alarm function and acts as a pilot differential actuator to provide the required operation of an approximately 5.5:1 ratio differential dry pipe control valve. This valve can also function as an open system Deluge valve or closed system Preaction valve for sprinkler systems that operate from separate detection systems where the supply liquid holds the valve closed until a detection system detects a fire and signals the deluge valve to open for discharge of suppressant liquid on the protected fire area.