American Conval bellows seal valve

The bellows sealing valve of Convo (USA) bellows sealing valve can meet all the strict requirements of - and ensure the service life of the bellows.
■The lowest life cycle cost in the industry
■ Fugitive emission grade seal
■ High cycle bellows
■ Online maintenance
Standard bellows seal dimensions
Its maximum size is
Pressure class
Pressure class up to
Standard forged materials
- - -
Other materials available on request
Accessories
Actuator - electric, pneumatic or hydraulic
Locking device - open, closed or two-way
Limit switch - one-way or two-way
Valve stem sleeve
Valve position indicator
No leakage port
Design features of bellows seal valve
Comparison of bellows seal valve and packing seal valve
Packing seal valve has two sealing boundary valves Rod surface seal and stuffing box wall seal. Bellows-sealed valves eliminate both leak paths. Bellows seal valves should be used when packing seal valves cannot reliably control gas or harmful liquid leaks. In all applications, mid-layer nickel-chromium iron welded bellows stem seals are more reliable than ordinary sliding stem seals.
Zero Fugitive Emissions
Each bellows assembly must pass a zero leakage test with a nitrogen gas spectrometer before conducting the valve body and valve seat leakage test. The bellows seal emitted no detectable leaks and far exceeded the standards of the Fugitive Emissions Testing Protocol method.
Bellows No Twist
The sturdy non-rotating poppet stem system prevents damaging twisting due to its advanced bellows design giving bellows sealed valves a long service life.
Three types of valve bodies
Bellows seal valves have three types of valve bodies: type, angle type and type.
Low operating torque
Manual bellows seal valves are equipped with a robust bearing system and grease nozzles to reduce operating torque to a minimum throughout the valve's service life.
Double auxiliary valve seat
The bellows seal valve is equipped with a high-performance back seal as the second stage stem seal to separate from the process medium when the valve is in the fully open state. The balance shaft packing gland and integral packing gland wrench used apply precise loads to the stem graphite packing seal to provide a superior seal as a reliable backup to the bellows seal.
Extend the service life of the valve seat
Since the valve seat and valve plug are made of strong cobalt chromium material, this ensures that the valve seat and valve plug can still close tightly during a very long service life, even if used The valve can also be closed tightly even in conditions with high number of opening and closing cycles and high flow rates. Seats made of cobalt-free materials are also available in nuclear and chemical applications.
Flexible design
Dual height bellows are provided to provide the maximum valve flow capacity (value) for each given pipe size. Test port (with water seal packing gland) can be requested.
Axial load packing system
The axial design ensures high concentricity and also eliminates the side load of the packing, reducing the wear force of the valve internal components. This design feature is critical to the valve's superior performance.
Pressure sealing valve cover
There are no solder joints and no gaskets or gaskets between the pressure sealing valve cover and the valve body. This structure is simple and effective. The integrity of the connection between the valve body and bonnet is achieved through numerous thermal cycle tests.
Single Gland
The simpler the design and the fewer parts, the better the performance of the valve in harsh environments. Durable one-piece stainless steel gland ensures valve longevity.
Pressure type upper seal
The pressure type upper seal greatly improves the integrity of the valve and ensures that the valve stem and valve core assembly actively stop at the limit position. The pressure-type upper seal protects the packing from pipeline pressure when the valve is fully open, thereby extending the service life of the packing.
Quick Online Repairability
The valve is easier to repair than any valve on the market. Valve online maintenance provides modular solutions which will lead to rising maintenance costs. Low valve acquisition cost is less important than low life cycle cost. Maintaining valves is far easier and less expensive than replacing competitor valves