Rubber wedge gate valve is a valve that combines the wedge sealing structure of the wedge gate valve with the rubber elastic sealing technology, and is designed to improve sealing performance and corrosion resistance.
Its core features are:
Wedge gate: The gate sealing surface is at a specific angle to the vertical centerline (such as 2°52', 5°, etc.), and the initial sealing is achieved through the wedge-shaped pressing force;
Rubber coating: The gate surface is coated with rubber material (such as EPDM or NBR), and the elastic deformation of the rubber is used to compensate for the wear or processing error of the sealing surface, thereby enhancing the sealing reliability.
Core structure and working principle Wedge seal pair
The gate and the valve seat are matched with a wedge angle. When closed, the valve stem thrust forces the contact surface of the two to form a metal-rubber composite seal;
The rubber layer deforms under pressure to fill the microscopic gap, effectively blocking the leakage of the medium.
Elastic compensation design
The flexibility of rubber can adapt to the deformation caused by temperature fluctuations or pipeline vibration, avoiding the jamming or leakage caused by thermal expansion and contraction of traditional metal seals;
In the medium containing particles, the rubber layer can buffer the impact of particles and reduce the damage of the sealing surface.
Performance advantages
High sealing: The dual role of rubber elasticity and wedge structure is suitable for low pressure or medium pressure fluctuation scenarios;
Corrosion resistance: Rubber materials (such as fluororubber) can resist corrosive media such as acids and alkalis, extending the life of the valve;
Low maintenance: After the rubber sealing surface is worn, it can be automatically compensated by the medium pressure to reduce manual intervention.
Typical application scenarios
Water treatment system: Municipal water supply and sewage treatment pipelines, adapted to the working conditions where the water contains impurities or corrosive components;
Chemical plant: Replace metal sealed gate valves when conveying corrosive liquids such as acids and alkalis;
Low-pressure steam pipelines: The temperature resistance of rubber is adapted to the cut-off requirements of medium and low temperature steam systems.
Selection and Restrictions
Applicable pressure limit: Rubber materials have low pressure resistance and are generally used for medium and low pressure pipelines below Class 150;
Temperature range: Conventional rubber (such as NBR) is usually applicable to temperatures between -20°C and 80°C. Fluororubber or special coatings are required for high temperature scenes;
Medium matching: The rubber type should be selected according to the chemical properties of the medium (such as EPDM acid and alkali resistance, NBR oil resistance).
Comparison with other gate valves
With traditional wedge gate valves: Rubber wedge gate valves sacrifice some high temperature and high pressure performance in exchange for better sealing elasticity and corrosion resistance;
With knife gate valves: Knife gate valves focus on the ability to shear impurities, while rubber wedge gate valves are more suitable for precise cutoff of clean or weakly corrosive media.