Dynamic Rod Seal Decoking Valve for Low-Force Sealing
Find Innovative SolutionsGenerate Solutions
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 premature failure of valve seats, reducing the mean time between repairs.
Innovation Solution
The decoking control valve employs a hydraulic rod seal with a seal ring and guide ring mechanism, which reduces the axial force needed for sealing by utilizing a low-friction seal ring and a guide ring to center the piston, minimizing wear and extending the valve's operational lifespan.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional piston-type valve with conical annular seat is used to create a watertight seal, then sealing effectiveness is improved, but axial force requirement increases and seat wear accelerates
Solution Approach 1:
The patent replaces the conventional mechanical conical annular seat sealing system with a hydraulic rod seal system. The hydraulic seal uses fluid pressure distributed along the rod length to create sealing force, substituting the concentrated mechanical contact of the conical seat with a distributed hydraulic sealing mechanism. This reduces peak axial forces while maintaining sealing effectiveness.
Solution Approach 2:
The patent introduces hydraulic pressure as the sealing mechanism. The hydraulic rod seal utilizes pressurized fluid acting on the rod surface to generate sealing force, replacing the solid-to-solid contact of the conical seat. The hydraulic pressure distributes the sealing force along the rod length, reducing wear and axial force requirements compared to the mechanical seat system.
2Reliability
If high axial force is applied to the valve actuator to maintain watertight seal, then sealing reliability is improved, but component wear increases and mean time between repair decreases
Solution Approach 1:
The patent replaces the high-force mechanical conical seat system with a hydraulic sealing system that distributes sealing forces. This substitution eliminates the concentrated stress on the conical seat and actuator components, significantly reducing wear rates and extending the operational life of moving parts while maintaining sealing reliability.
Solution Approach 2:
The patent changes the sealing mechanism from a high-force concentrated mechanical contact to a lower-force distributed hydraulic pressure system. By changing the sealing parameter from concentrated axial force to distributed fluid pressure, the system achieves the same sealing reliability with reduced stress on components, thereby extending mean time between repairs.
3Reliability
If conventional conical annular seat is used for sealing, then sealing effectiveness is achieved, but valve requires frequent maintenance and repair
Solution Approach 1:
The patent replaces the conventional mechanical conical annular seat with a hydraulic rod seal system. This substitution eliminates the wear-prone conical seat contact surfaces, reducing maintenance requirements. The hydraulic seal system has fewer wear points and can be maintained less frequently while maintaining equivalent or superior sealing effectiveness.
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 axial force requirement, reducing wear on moving components and increasing the mean time between repairs, while maintaining effective sealing and fluid flow control.
Implementation Method 1
low-friction seal ring
Implementation Method 2
guide ring to center the piston
Implementation Method 3
seal ring activates at one outlet port
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The decoking control valve includes a piston (110), a cylinder (120), and a hydraulic rod seal (135) 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 (147) of the cylinder that places the hydraulic rod seal next to the piston. The hydraulic rod seal has a seal ring (145) 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.