Two-Stage Spring-Loaded Control Valve for Low Pressure
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Solution Overview
Problem
Existing fluid treatment control valves face challenges in opening under low source inlet pressures, leading to potential stalling and increased leakage due to insufficient friction between the piston head seal and its bore, which compromises the system's efficiency and reliability.
Innovation Solution
A two-stage spring-loaded control valve design with a piston head and stem assembly, where initial movement does not open the valve due to coil spring compression, allowing increased seal friction without compromising the ability to open under lower pressures, ensuring reliable operation and reduced leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If the control valve uses a spring-loaded mechanism to open under low source inlet pressures, then the valve can operate at lower pressures, but the seal friction between the piston head seal and bore increases, potentially causing stalling
Solution Approach 1:
The valve opening process is segmented into two distinct stages: an initial stage where the piston head moves but the valve remains closed due to spring compression, and a second stage where the valve fully opens. This segmentation allows the system to overcome seal friction without stalling by separating the compression phase from the opening phase.
Solution Approach 2:
The coil spring performs preliminary action by compressing during the initial piston head movement, storing energy that later assists in overcoming the seal friction. This preliminary compression action prepares the system for the subsequent full valve opening, preventing stalling under low pressure conditions.
2Stress or pressure
If the control valve is designed to open easily under low pressure, then pressure requirements are reduced, but leakage increases due to insufficient friction between seal and bore
Solution Approach 1:
The valve design dynamically adjusts the sealing force during operation. The coil spring provides variable friction characteristics that adapt to the operating pressure, allowing the valve to seal effectively under low pressure conditions while maintaining reliable opening. The spring compression during initial movement creates a dynamic sealing force that prevents leakage without requiring high operating pressure.
3Object-generated harmful factors
If the control valve uses increased seal friction to prevent leakage, then leakage is reduced, but the valve becomes more difficult to open under low source inlet pressures
Solution Approach 1:
The valve opening process is segmented into two distinct stages: an initial stage where the piston head moves but the valve remains closed due to spring compression, and a second stage where the valve fully opens. This segmentation allows the system to overcome seal friction without stalling by separating the compression phase from the opening phase.
Solution Approach 2:
The coil spring performs preliminary action by compressing during the initial piston head movement, storing energy that later assists in overcoming the seal friction. This preliminary compression action prepares the system for the subsequent full valve opening, preventing stalling under low pressure conditions.
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 control valve effectively operates at lower source inlet pressures, reducing the risk of stalling and leakage while maintaining efficient fluid treatment, allowing for increased seal friction without compromising the opening mechanism.
Implementation Method 1
Initial movement of the piston head does not produce movement in the stem due to the coil spring acting between the stem and the piston head
Implementation Method 2
A second turbine, operatively connected to a regeneration sequence control element (in the form of a disk) is rotated by a stream of water that is activated at the beginning of the regeneration cycle
Implementation Method 3
the seat remains engaged with the associated sealing surface due to fluid pressure acting on the seat
Data Source
AI summary
A water treatment system including a pair of water treatment tanks, each tank defining a flow path extending from a tank inlet to a tank outlet and containing a water treatment material disposed along the flow path for treating water as it travels from the inlet to the outlet. A system controller controls which of the tanks is on-line and which of the tanks is off-line and controls the regeneration of an exhausted tank. A multi-stage, spring-loaded control valve assembly controls the communication of fluid to a regeneration control turbine and includes a piston head and a relatively movable seat-carrying stem. A spring urges the stem away from the piston head such that initial movement of the head compresses the spring but does not produce movement in the seat. Sufficient movement of the piston head produces movement in the seat, thereby causing the seat to open pressure.