Rotating disc valve application
FREE-VALVE Rotating disc valve features high wear resistance, large flow capacity, flexible operation and reliable sealing. It is suitable for high-wear and high-corrosion process systems such as polysilicon containing solid particles, fly ash, and lithium cobalt oxide powder for lithium batteries.
- Overview
There are many high- wear special working conditions in petrochemical plants, such as the transportation of coal powder and coal slag in the coal gasification plant, and the transportation of silicon powder in the organic silicon plant and silane production plant.The common feature of these conditions is that the conveyed material is granular and very hard. Under such conditions, high wear resistance is required for of pneumatic cutting-off valves. The initial used pneumatic cutting-off valve is the full-port O-type ball valve.To cope with high-wear and harsh conditions, we adopted overlay welding of copper-titanium alloys or tungsten carbide coating hardening on the valve ball and valve seat. Although the ball is hardened, the powder causes severe wear to the ball and seat during use, and the service life of the ball valve is usually only a few months, resulting in frequent valve replacements and increased operating costs.
Some end users have attempted to replace metal ball valve with ceramic ball valves, with the valve body being fully lined with ceramic and the ball and seat being made of ceramic material. In actual operating, the service life of ceramic ball valves is much longer than metal ball valves, significantly reducing maintenance costs. However, ceramic ball valves have the same structural form as metal ball valves, and during the process, they will also wear. Moreover, ceramics are brittle and are not suitable for use in high-temperature and high-pressure environments. Large-diameter ceramic ball valves are expensive.
Rotating disc valve emerged as a cutting-off valve. FREE-VALVE Rotating disc valve features high wear resistance, large flow capacity, flexible operation and reliable sealing. It is suitable for high-wear and high-corrosion process systems such as polysilicon containing solid particles, fly ash, and lithium cobalt oxide powder for lithium batteries.
2. Rotating disc valve compared to the ball valve
| Feature Comparison | ball valve | Rotating disc valve |
| Seat structure form
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Although the flow channel of the ball valve is simple, Seat structure is rather complex. | The flow channel of the rotating disc valve with single disc is irregular, but the valve seat structure is simple. |
| Self-cleaning property | The sealing surface between the ball and seat of the ball valve does not have self-cleaning capabilities. It is prone to wear, resulting in the leakage of materials into the cavity between the seat and body. | The seat and disc of the rotary disc valve have the capabilities of self-cleaning and self-polishing, which prevents the sealing surfaces of the disc and seat from wearing out, thus ensuring the service life. |
3. Structural of the rotating disc valve
The rotating disc valve is a type of valve that achieves quick opening and closing by controlling the sliding of the disc. This type of valve is specifically designed for harsh conditions with severe wear. The sealing pair of the valve is a flat seal, which is easy to process and ensures better sealing. The wide sealing surface is less likely to experience severe through-type leakage, and the sealing reliability is higher.
Working process: The pneumatic actuator rotates the disc to a certain angle through the valve stem and rocker arm to achieve the opening and closing of the valve. During this process, the disc sealing surface is always tightly pressed against the seat by Spring preload force, while also allowing the disc to move vertically along the sealing surface to compensate for thermal expansion and contraction of the valve. When the valve is opened or closed, the disc rotates freely on the seat, continuously polishing the sealing surface. This self-polishing design enables the rotating disc valve to continuously clean and polish the sealing surface under harsh conditions,maintaining good valve sealing performance without wearing the valve seat and disc. The disc motion and self-rotation are shown in the figure below:
4. Conclusion
After long-time use, the structural advantages of the rotating disc gate valve, combined with its unique self-polishing and self-cleaning sealing surface design, enable the rotary disc valve to exhibit excellent wear resistance under severe abrasive conditions compared to ball valve. It features reliable sealing and a long service life,avoiding frequent valve replacements and saving significant labour and resources for the enterprise. Therefore, FREE-VALVE rotary disc gate valve has great potential for use in harsh and highly abrasive conditions such as pneumatic conveying.
