Thin film pneumatic bellows flow control valve

The thin film pneumatic bellows flow control valve achieves precise regulation of pipeline medium flow through the synergistic effect of flexible bellows structure and thin film actuator. The core design adopts multi-layer metal bellows as the valve stem sealing component, replacing the traditional packing sealing form, which can effectively avoid the problem of medium leakage and is suitable for corrosive, high-temperature or clean fluid conditions with high sealing requirements. The actuator of this valve consists of an elastic diaphragm, a spring component, and an air chamber. The diaphragm is driven to deform by the 4-20mA standard signal or pneumatic pressure signal, which drives the linear displacement of the valve core and changes the flow cross-sectional area. The bellows component and valve stem adopt an integrated design, which maintains flexible contact between the sealing surface and the valve seat during dynamic adjustment, which can adapt to frequent opening and closing requirements and reduce mechanical wear. The valve body is usually made of corrosion-resistant materials such as 316L stainless steel and Hastelloy, combined with a hard alloy seat structure, which significantly improves the service life of the valve in high-pressure and particle containing environments.

In terms of technical features, the bellows sealing structure can reduce the maintenance frequency of 90% and above compared to traditional packing sealing, making it particularly suitable for control scenarios involving toxic and harmful media or high-purity fluids. The response time of the actuator is controlled within the range of 0.5-3 seconds, supporting proportional integral derivative (PID) adjustment mode, and can seamlessly integrate with the DCS system. Some models are equipped with manual operation wheels and opening indicators to ensure that emergency operations can still be carried out in the event of power outages or gas source failures.

The application fields cover industries with strict hygiene requirements such as fine chemicals, biopharmaceuticals, and food processing, especially suitable for precise control of steam thermal systems, vacuum pipelines, and high viscosity fluids. By adjusting the number of corrugated tube layers, membrane material, and spring stiffness, it can be adapted to the temperature range from - 50℃ to 450℃ and the pressure rating of PN16-PN100.

In terms of maintenance, modular design is adopted, and the bellows components and valve body can be quickly separated and replaced, reducing downtime. It is recommended to regularly check the cleanliness of the air source filtration device and monitor the fatigue status of the bellows. Calibration should be carried out when the adjustment accuracy deviation exceeds ± 2%. Through structural optimization, this type of valve reduces the fluid resistance coefficient to below the 60% of traditional valves while ensuring regulation accuracy, resulting in significant energy-saving benefits.