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 system, which reduces the axial force needed for sealing by utilizing a low-friction material and geometry to generate contact pressure, and includes features like split grooves and axial grooves to manage pressure differentials and prevent seal blowout.
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 the valve can control high pressure water flow, but the valve actuator requires high force leading to rapid wear and frequent maintenance
Solution Approach 1:
The patent replaces the conventional mechanical piston-to-seat sealing system with a hydraulic rod seal system. The hydraulic seal uses fluid pressure to create sealing force between the rod seal and the seat, eliminating the need for high axial mechanical force from the actuator. This substitution of mechanical sealing with hydraulic sealing resolves the contradiction by maintaining sealing effectiveness while dramatically reducing the force requirement from the actuator, thereby extending mean time between repairs.
Solution Approach 2:
The patent employs hydraulic principles by using high pressure water to energize the rod seal. The hydraulic pressure creates the necessary sealing force between the rod seal and seat, replacing the mechanical force that previously caused wear. This application of hydraulic sealing allows the valve to maintain watertight seals without requiring high axial forces from the actuator, thus improving reliability while reducing force requirements.
2Reliability
If the valve actuator provides sufficient force to develop a watertight seal between piston and valve seat, then sealing is achieved, but the repeated opening and closing causes seat failure
Solution Approach 1:
The patent replaces the mechanical piston-to-seat contact sealing system with a hydraulic rod seal system. Instead of relying on repeated mechanical contact between the piston and conical annular seat, the hydraulic seal uses fluid pressure to maintain sealing. This eliminates the wear mechanism caused by repeated mechanical contact, allowing the valve to withstand numerous opening and closing cycles without seat failure, thereby improving both reliability and operational durability.
Solution Approach 2:
The patent changes the sealing mechanism from mechanical contact to hydraulic pressure-based sealing. By altering the fundamental parameter of how sealing force is generated (from mechanical axial force to hydraulic pressure), the system eliminates wear associated with repeated mechanical contact. This parameter change allows the valve to maintain sealing effectiveness over thousands of operations without seat degradation.
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 design significantly extends the mean time between repairs by reducing wear on moving components and preventing seal failure, enhancing the durability and reliability of the decoking control valve.
Implementation Method 1
The seal rings are activated by an activating agent. When the piston moves within the cylinder, the seal ring activates at one outlet port, and allows fluid to flow out of another outlet port.
Implementation Method 2
The hydraulic rod seal features a seal ring that interacts with the piston, and the seal rings are activated by an activating agent. The low-friction material and geometry to generate contact pressure
Data Source
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.