Titanium plug valve double seal structure through the design of dual seal element and multi-stage seal mechanism, greatly improved the reliability of seal. Specific functions and improvements are as follows:
I. The Core Function of the Dual-Sealing Structure
Bidirectional Leak Prevention Capability
Titanium ball are designed to be double sealed with two sets of sealing elements (e.g. soft seal + hard seal composite structure) at either end of the ball or on a sealed surface. For example, titanium ball has a two-channel groove seal ring structure that allows soft seal bushing to be firmly embedded in the valve body, while hard seal (e.g. metal to metal) acts as a backing, creating a dual barrier. This design ensures zero leakage when the medium flows in both directions, and is particularly suitable for tight sealing requirements, such as aviation kerosene and natural gas.
Adapting to complex working conditions
Temperature compensation: Double groove sealing ring can absorb the slight deformation of the bushing caused by temperature change and avoid the gap between hot and cold shrinkage the sealing surface.
Media erosion resistance: Soft seals (e.g. PTFE, FR) are highly corrosion resistance, while hard seals (e.g. hard chrome coating, metal backing) are abrasion and fire resistant. The combination of the two can resist the erosion of oxidizing corrosive media, viscous medium or crystallization working conditions.
Online Maintenance and Safety
Double sealing structure is adopted to achieve on-line maintenance without removing pipe replacement seals. For example, a double sealed lifting stop valve with a bottom end cover design that allows for direct removal of the sealed slider for replacement, reducing downtime. In addition, the built-in pressure relief device can detect seal failure and release pressure, prevent abnormal pressure rise in the valve cavity, and improve system safety.
II. Technical Paths to Enhancing Sealing Reliability
Multi-level sealing design
Soft-hard composite sealing: Soft seal (e.g. rubber, PTFE) provides the initial sealing force, while hard seal (e.g. metal, ceramic) provides secondary assurance. For example, the sealing slide of a double-sealed ball valve compacts the elastic seal ring when closed and the metal backing forms a fire-resistant seal, reducing the leakage rate to zero.
Double discharge function: press two separate sealing sliding plates at the upper and bottom of the valve hole to achieve double plug. When the discharge valve is opened, the sealing effect can be tested to ensure that media is discharged through the discharge valve to avoid contamination if there is a one-way leakage.
Dynamic Seal Optimization
Contactless cover design: In the process of valve opening and closing, the valve body cover and the sliding plate cover do not touch directly, reducing friction loss and prolonging service life. For example, a double-sealed plug valve is closing method and the stopper rotates 90 degrees and then moves vertically. The synchronous indicator device shows the status of the switching to ensure that the sealing surfaces is not worn.
Fluid dynamic pressure compensation: Optimize valve port geometry (e.g. cone angle, channel curvature radius, etc.) to 30-45°, reduce pressure drop loss to less than 0.5 bar, and compensate for static the insufficient static preload using fluid pressure gradient to form dynamic pressure bearing effect.
Materials and process innovation
High-performance sealing materials: sleeve material are selected according to medium characteristics, such as PTFE (PTFE) -filled lubricant to extend service life and fluoride fluororubber compression molding molding to ensure that they do not fall off.
Intelligent Monitoring and early warning
Embed electrically active polymer (EAP) seals that adjusts deformation stiffness to pressure fluctuations (±50 bar) in real time via external electrical signals.
By using machine learning algorithm to analyze parameters such as seal surface temperature and pressure, the failure probability predicted to 95% confidence, and the response time of alarm is shortened to less than 10 ms.
III. Application Scenarios and Advantages
Titanium ball valve double sealing structure is widely used in petrochemical industry, natural gas transportation, water treatment and so on, especially in the following situations:
Two-way flow pipe: For example, steel factory circulating water two-way regulation pipe needs to adapt to the reverse flow of media, there are strict requirements for sealing.
High pressure differential conditions: The fluid lubrication film (between 0.1 and 2 μm in thickness) reduce surface wear, and the Reynolds equation describes the membrane pressure distribution that ensures seal stability at a high pressure differential of 100 bar.
Corrosive medium environment: Inert coatings (e.g. zirconia ceramic) form a chemical barrier with the highest level of corrosion resistance ISO15156-2 standard and are suitable for highly corrosive media such as hydrofluoric acid.
