| Bellows-sealed globe valve | Process piping that needs shutoff and, depending on the design, flow regulation; used in chemical, petrochemical, and utility services. | A welded metal bellows seals around the moving stem, reducing the potential for process fluid to escape through the stem packing area. | Confirm pressure and temperature ratings, flow direction, end connections, body material, and suitability of the bellows alloy for the fluid. | Documented design ratings, material traceability, production testing, and inspection procedures appropriate to the specified service. |
| Low-emission process service | Handling hazardous, toxic, volatile, or environmentally sensitive fluids where stem leakage must be controlled. | The bellows provides a secondary stem seal; many designs also retain conventional stem packing as a backup barrier. | Evaluate bellows cycle life, corrosion compatibility, packing arrangement, and any project-specific emissions or leakage-test requirements. | Ability to provide relevant test documentation and clearly state the limits and conditions of any leakage-performance claims. |
| Vacuum and high-purity service | Vacuum systems and selected semiconductor, laboratory, and clean-process installations, subject to the valve’s cleanliness and pressure specifications. | A metal bellows can maintain a sealed moving-stem boundary without relying on a sliding stem seal exposed to the process. | Check vacuum rating, internal surface finish, cleaning and packaging requirements, outgassing considerations, and connection type. | Controlled cleaning processes, suitable inspection records, and manufacturing procedures aligned with the cleanliness specification. |
| Steam and hot-fluid service | Steam, condensate, and other hot-fluid systems when the selected valve is rated for the operating conditions. | The bellows isolates the stem movement from the process fluid, while the valve body and trim control the flow path. | Verify the allowable pressure-temperature range, thermal cycling limits, bellows fatigue rating, and suitability for the specific fluid. | Engineering data for the complete valve assembly, including the bellows, rather than material data alone. |
| Corrosive chemical service | Chemical processing applications where the process fluid may attack standard valve materials. | A welded metal bellows forms the stem seal, but it must be selected to withstand the process environment. | Assess compatibility of the bellows, body, trim, and welds with the fluid, concentration, temperature, and contaminants. | Material certificates, weld-quality controls, and technical support for application-specific material selection. |
| General manufacturer comparison | Procurement and specification review across industrial applications; suitability depends on the actual duty and applicable project standards. | Bellows valves are selected to limit stem leakage, but no bellows design is suitable for every pressure, temperature, fluid, or operating cycle. | Compare design documentation, material options, dimensional standards, testing scope, service support, and stated operating limits. | Request technical datasheets, quality-system information, inspection and test records, and references relevant to the intended service. |