What Is a Bellow Valve
A bellow valve, also known as a bellows seal valve, is a type of industrial valve designed to completely prevent leakage of fluid to the external environment. It uses a metal bellows as a dynamic seal element between the valve stem and body, replacing the traditional packing method. This design is particularly effective in toxic, hazardous, flammable, or high-purity fluid systems where leakage must be minimized or eliminated.
How Does a Bellow Valve Work
The metal bellows in the valve expands and contracts as the valve stem moves, creating a hermetic seal that isolates the fluid inside the valve from the atmosphere. The bellows are welded to both the valve stem and the bonnet, ensuring zero stem leakage during operation. A secondary packing seal is often added for double safety.
Where Are Bellow Valves Used
Bellow valves are widely used in industries where leak-free operation is essential:
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①Marine and shipbuilding (e.g., fuel oil and chemical systems)
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②Petrochemical and chemical processing
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③Pharmaceuticals
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④Nuclear and power plants
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⑤Semiconductor manufacturing
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⑥Cryogenic and high-vacuum systems
Advantages of Bellow Valves
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①Zero stem leakage, ideal for hazardous or flammable media
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②Long service life due to flexible yet durable bellows
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③Double sealing system (bellows + packing)
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④High operational safety and environmental protection
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⑤Meets stringent industry standards for emission control (e.g., ISO 15848, TA-Luft)
Key Features
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①Material: Stainless steel, carbon steel, or alloy body
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②End connections: Flanged, threaded, or welded
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③Bellows: Multi-ply stainless steel for flexibility and durability
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④Operation: Manual handwheel or actuator
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⑤Design types: Globe valve style (most common), angle or Y-pattern
Post time: Jul-18-2025