Dynamic Sealing Ball Valve Reduces Actuator Torque
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Solution Overview
Problem
Ball valves experience high torque due to sealing configuration, manufacturing variances, and operational characteristics, leading to the need for oversized actuators that are costly and power-intensive.
Innovation Solution
A dynamic sealing configuration using a resilient, shaped member behind the downstream seal and a spring-biased upstream seal with a ramped surface and o-ring, allowing for variable sealing force based on pressure conditions, reducing deformation and indentation of seals and minimizing torque requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fixed sealing pressure is applied based on maximum pressure, then leakage prevention is ensured, but torque requirement increases
Solution Approach 1:
The patent implements dynamic sealing pressure that automatically adjusts based on actual operating conditions. The sealing mechanism transitions from fixed static pressure to dynamic pressure that responds to valve position and operating conditions, reducing unnecessary sealing force during normal operation while maintaining adequate sealing when needed.
Solution Approach 2:
The patent changes the sealing pressure parameter from a fixed value to a variable value that adapts to operating conditions. By making the sealing pressure a dynamic parameter rather than a constant, the system optimizes the balance between reliable sealing and minimal torque requirement.
2Reliability
If oversized actuators are used to overcome manufacturing variances, then reliability is improved, but cost and device complexity increase
Solution Approach 1:
The dynamic sealing mechanism compensates for manufacturing variances by adapting sealing pressure in real-time, eliminating the need for oversized actuators designed to handle worst-case scenarios. The system becomes responsive to actual conditions rather than being designed for maximum possible deviations.
Solution Approach 2:
The sealing system self-adjusts to compensate for manufacturing tolerances and wear, reducing the need for oversized components. The dynamic sealing mechanism automatically compensates for variations, making the system self-correcting rather than relying on conservative design margins.
3Reliability
If high sealing pressure is maintained, then seal reliability is improved, but energy consumption increases
Solution Approach 1:
The patent implements dynamic sealing pressure that adjusts to actual operating conditions, maintaining high sealing force only when necessary for reliable sealing while reducing sealing force during normal operation. This dynamic adjustment directly reduces the energy required to maintain the seal compared to continuously high sealing pressure.
Solution Approach 2:
The sealing pressure is applied periodically or as needed rather than continuously at maximum levels. The dynamic sealing mechanism activates or intensifies sealing pressure only when operating conditions require it, creating a periodic or conditional sealing action that reduces overall energy consumption.
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 significantly reduces the torque required to reposition the valve member, enabling the use of smaller, less costly actuators and improving operational efficiency by adapting to varying pressure conditions.
Implementation Method 1
a resilient, shaped member behind the downstream seal
Implementation Method 2
a spring-biased upstream seal with a ramped surface and o-ring
Data Source
AI summary
A ball valve having reduced torque requirements for rotation is presented. Torque reduction is realized by providing a shaped sealing back member to provide a back force behind essentially the entire sealing surface of the downstream seal. Torque reduction is also realized by providing a dynamic sealing configuration that varies the sealing force over the valve's operating pressure conditions. An initial bias sealing force is applied by a spring member which also provides a low uniform as-assembled valve torque. As fluid pressure increases, the sealing pressure also increases as an o-ring is forced along a ramped surface of the seal. As inlet pressure decreases, the o-ring is allowed to back down the ramped surface to reduce the sealing force against the valve member. This sealing configuration allows for reverse flow or improper installation of the ball valve, and bottoms out to maintain a sealing force at higher back pressure conditions.