Decoking Control Valve With Dynamic Rod Seal for Lower Axial Force
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Solution Overview
Problem
Conventional decoking control valves in petroleum refining operations face frequent maintenance due to high axial forces required for sealing, leading to rapid wear and leakage, reducing the mean time between repairs.
Innovation Solution
The decoking control valve employs a hydraulic rod seal with a seal ring and guide ring system, reducing the axial force needed for sealing and using wear-resistant materials to extend the valve's operational life, along with a design that prevents seal blow-out and pressure differential issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional piston-type valve with conical annular seat is used to create watertight seal, then sealing performance is improved, but axial force requirement increases and seat wear accelerates
Solution Approach 1:
The patent replaces the conventional mechanical piston-to-seat contact sealing system with a hydraulic rod seal system. The hydraulic seal uses fluid pressure and a rod seal mechanism to create the watertight seal, eliminating the need for high axial forces to press a piston against a conical annular seat. This substitution resolves the contradiction by maintaining sealing performance while dramatically reducing the axial force requirement and preventing seat wear.
2Reliability
If high axial force is applied to create watertight seal between piston and valve seat, then sealing performance is improved, but seat failure occurs due to repeated opening and closing
Solution Approach 1:
The patent replaces the mechanical piston-to-seat contact system with a hydraulic rod seal system that uses fluid pressure and a rod seal mechanism. This eliminates the repeated mechanical contact and wear between the piston and conical annular seat, thereby preventing seat failure and significantly extending the valve's operational life and mean time between repairs while maintaining effective sealing.
Solution Approach 2:
The patent changes the sealing mechanism from mechanical contact (piston bearing on conical seat) to hydraulic sealing (rod seal with fluid pressure). This parameter change in the sealing approach eliminates the wear caused by repeated opening and closing cycles, extending the stationary components' duration and reliability.
3Reliability
If conventional piston and valve seat sealing mechanism is used, then sealing is achieved, but rapid wear occurs and valve becomes unserviceable
Solution Approach 1:
The patent replaces the conventional piston-to-seat mechanical sealing system with a hydraulic rod seal system. The rod seal mechanism, actuated by hydraulic pressure, creates the watertight seal without the rapid wear associated with repeated mechanical contact between the piston and conical annular seat. This improves serviceability by eliminating the wear-induced failures that render the valve unserviceable, thereby extending maintenance intervals and improving ease of repair.
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
This solution significantly lowers the wear rate of moving components and increases the mean time between repairs by reducing the axial force required for sealing and using wear-resistant materials, while maintaining effective sealing performance.
Implementation Method 1
a hydraulic rod seal with a seal ring and guide ring system, reducing the axial force needed for sealing
Data Source
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AI summary
The decoking control valve includes a piston, a cylinder, and a hydraulic rod seal at the outlet ports. The piston can move translational inside the cylinder along a fixed direction. The cylinder houses the hydraulic rod seal in a groove of the cylinder that places the hydraulic rod seal next to the piston. The hydraulic rod seal has a seal ring in contact with the piston, and the seal rings are activated. As the piston translates within the cylinder, the seal ring will activate at one outlet port and allow fluid to flow out of another outlet port.