Valve Stem Leakage Blocking with Hydraulic Sealing Oil Pressure
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Solution Overview
Problem
Conventional valve stem packing devices rely on frictional contact, leading to fluid leakage through worn areas and unstable sealing due to changing pressure, requiring frequent replacements and maintenance.
Innovation Solution
A leakage blocking device utilizing a bonnet, upper cover, and piston with a sealing oil chamber, where leaked fluid increases oil pressure to prevent leakage without frictional contact, using O-rings for additional sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sealing member such as gland packing is used and pressed onto the valve stem, then fluid leakage is prevented, but wear occurs on the valve stem due to repeated movement and frictional contact
Solution Approach 1:
The patent replaces the mechanical friction-based sealing system (gland packing pressed against valve stem) with a hydraulic pressure-based sealing system. A piston receives fluid pressure on its bottom surface and transmits this pressure through oil in a sealing chamber to an upper surface, creating a pressure barrier that prevents leakage without direct mechanical contact between sealing elements and the moving valve stem.
Solution Approach 2:
The patent uses hydraulic principles by introducing fluid pressure to the bottom surface of the piston, which then transmits this pressure through incompressible oil in the sealing chamber to the upper surface. This hydraulic pressure transmission creates a sealing effect that blocks leakage paths without requiring frictional contact, thereby preventing wear on the valve stem while maintaining reliable sealing.
2Reliability
If gland packing is pressed to seal the gap, then fluid leakage is blocked, but contact force changes with pressure variations making stable sealing difficult
Solution Approach 1:
The piston mechanism provides automatic feedback response to pressure variations. When fluid pressure increases, the bottom surface of the piston receives greater force, which automatically increases the pressure transmitted to the upper surface through the sealing oil, maintaining effective sealing. When pressure decreases, the force decreases proportionally, allowing the system to adapt dynamically while maintaining stable sealing performance.
Solution Approach 2:
The patent changes the sealing mechanism from relying on mechanical contact force (which varies with pressure) to relying on hydraulic pressure transmission. The pressure acting on the bottom surface of the piston is transmitted through the incompressible oil to the upper surface, creating a sealing force that automatically adjusts to pressure variations while maintaining stability.
3Reliability
If conventional packing devices are used, then sealing is achieved through frictional contact, but frequent replacement is required due to wear and leakage
Solution Approach 1:
The patent eliminates the mechanical friction-based packing system that requires frequent replacement due to wear. Instead, it uses a hydraulic pressure transmission system where the piston and sealing oil create a leakage barrier without direct frictional contact, dramatically reducing wear and extending the service life of the sealing system, thereby reducing maintenance frequency and improving productivity.
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
Effectively blocks fluid leakage with increased oil pressure, enhancing durability by reducing frictional force and maintaining consistent sealing without the need for frequent replacements.
Implementation Method 1
a bottom pressure acting surface of a smaller cross-sectional area at a lower end to receive pressure of leaking fluid through a gap between the through-hole and the valve stem
Implementation Method 2
a sealing oil chamber filled with pressurized sealing oil
Implementation Method 3
O-rings for blocking fluid leakage may be installed circumferentially on the inner wall of the through-hole of the piston
Data Source
AI summary
A leakage blocking device of a valve is disclosed. When a fluid flowing in a flow path 11 leaks through a gap between the outer circumferential surface of a valve stem bottom (21) and a bottom guide hole (31), a plug 53 of a piston 50 is pushed into a sealing oil chamber 45 by a pressure P1 of the leaked fluid acting on a bottom pressure acting surface S1 of the piston and pressurizes a sealing oil L in the sealing oil chamber 45 to a pressure P2 higher than the pressure P1 of the leaked fluid, thereby blocking leakage of fluid of the valve.