Vacuum Inline Valve (SUS304, Manual, Bellows Seal)

Model: PVV-04

PVV-04 is a manual in-line vacuum valve with a bellows seal, supporting a size range from NW16 up to NW160. With the stem drive isolated from the atmosphere by a metal bellows that separates the stem seal from outside air, and 100% helium leak tested prior to shipment, it is used for line on/off applications in high-vacuum (HV) environments.

Features

• Compact design for easy installation in confined spaces
• Internal oil removal (CLEAN AND OIL FREE)
• 100% helium leak tested
• Custom manufacturing available per customer needs
• Available in large sizes NW16-160

Specifications

Frequently Asked Questions

What is the difference between bellows seal and standard O-ring seal?

O-ring seals have the stem in direct contact with the atmosphere, so micro-leakage may gradually increase over time due to O-ring wear and hardening. Bellows seals have the entire stem encased in a metal bellows, minimizing contact with the atmosphere and structurally reducing the impact of seal aging in repetitive use environments. In corrosive gas environments, contact with the stem exterior itself is reduced, making it easier to secure margin in inspection cycle planning.

What is the operating life of the bellows?

Standard specifications are designed targeting approximately 10,000 or more open/close cycles. However, actual life varies with operating frequency, differential pressure, operating temperature, and gas type, so for lines expecting high-frequency automatic cycles, let us know the conditions and we will propose high-cycle specifications or regular replacement plans.

What level of vacuum can it be used to?

PVV-04 is designed for line interruption in the high vacuum (HV) range. The actual achievable vacuum varies greatly with chamber volume, pumping system configuration, operating temperature, and the vapor pressure of the handled gas, and UHV ranges require separate review such as metal seat or bake specifications. Provide your specific operating environment (base pressure, chamber volume, process gas, operating temperature) and we will guide you on suitability and options.

How should I select the NW size?

In the NW16 to NW160 range, sizes are generally determined based on chamber volume and target pumping time. If pipe conductance calculation is needed, provide chamber volume, pump capacity, target base pressure, and pipe length information and we will review the appropriate NW size.