VB-HP · Bellows Sealed Valves

VB-HP Bellows Sealed Valve

Hermetic welded metal bellows stem seal for toxic and corrosive gas service with 1/4, 3/8 and metric port options.

Built for ultra high purity specialty gas service, the VB-HP belongs to the Bellows Sealed Valves family covering isolation, switching and flow control.

high pressure bellows sealed valve316L wetted bodyHelium leak tested

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VB-HP Bellows Sealed Valve overview

The VB-HP is a high purity specialty gas valve specified with 1/4, 3/8, 6mm, 8mm ports, a flow coefficient of 0.3 and a maximum working pressure of 350 PSI. Hermetic welded metal bellows stem seal for toxic and corrosive gas service with 1/4, 3/8 and metric port options. It is intended for the point in a high purity gas system where a clean, repeatable shut-off or switching function is needed without introducing a packed stem seal into the process stream.

The wetted flow path is kept short and smooth, with a metal or hard-polymer sealing element selected for the gas. Seats and closures are machined to a controlled finish so the valve can be purged quickly and will not hold up moisture between process cycles. A short, smooth flow path and low internal volume make purge cycles fast, which matters when a line changes between reactive gases. Available end connections are vcr face seal (male/female), butt weld, compression, so the same body can be used on face-sealed tool hook-ups, welded distribution headers or field-installed instrument lines.

Key features and design benefits

• 1/4, 3/8, 6mm, 8mm ports, Cv 0.3 — sized for high pressure bellows sealed valve flow duty without excess dead volume
• 350 PSI maximum working pressure with a reinforced seat and helium-tested pressure envelope
• The wetted flow path is kept short and smooth, with a metal or hard-polymer sealing element selected for the gas.
• Electropolished wetted surfaces for fast dry-down and low moisture retention
• Manual or normally closed pneumatic actuation; pneumatic versions fail closed on loss of instrument air
• VCR, butt weld, compression or cylinder-standard end connections to match the installation
• Cleanroom assembly, double-bag packaging and per-valve leak records available

Technical specifications

Values above describe the standard configuration of model VB-HP. Final materials, seat, actuation, test limits and certification are confirmed on the order-specific datasheet issued with your quote.

Model comparison within the Bellows Sealed Valves family

Select the body by flow demand rather than by port size alone. The table below compares the VB-HP with its sibling models on the three parameters that drive a gas system design: port size, flow coefficient and maximum working pressure.

Construction and wetted materials

The wetted flow path is kept short and smooth, with a metal or hard-polymer sealing element selected for the gas. Seats and closures are machined to a controlled finish so the valve can be purged quickly and will not hold up moisture between process cycles. For the VB-HP, the wetted path is machined from 316L VIM/VAR stainless steel with low inclusion and controlled sulfur content, then electropolished. A nickel-based diaphragm or seat alloy can be substituted where halide or hydride gases demand it.

End connections and port options

The VB-HP is normally ordered with 1/4, 3/8, 6mm, 8mm ports. Connection choice affects both cleanliness and maintainability: VCR face seals give a repeatable metal-to-metal seal for tool hook-up, orbital butt welds suit permanent high purity headers, and compression fittings are used where a line must be assembled in the field.

Gas compatibility and typical applications

Model VB-HP is selected for high purity N2, Ar, He, H2, O2, and corrosive hydride or halide mixtures when the wetted alloy is matched to the gas. Always state concentration, temperature and any moisture or oxygen limit so the wetted alloy and seat can be confirmed before release.

• Semiconductor tool hook-up and gas cabinet isolation branches
• Valve manifold boxes, changeover panels and purge / vent legs
• High purity laboratory, analytical instrument and calibration gas lines
• Photovoltaic, MOCVD and hydrogen distribution systems
• Related application guides:
• MOCVD & LED Process Gas
• Corrosive & Toxic Specialty Gases

Installation, purging and handling

Install the VB-HP with the flow direction and port orientation shown on the approved drawing. Keep the protective caps in place until the joint is made, tighten face-seal fittings to the specified torque, and purge with dry inert gas before introducing process gas. Because the internal volume is low, a short cyclic purge is normally enough to reach the required moisture level.

• Handle with clean gloves in a controlled area; do not open the double bag until installation
• Use orbital welding or certified face-seal glands on high purity headers
• Purge with dry N2 or Ar and verify moisture / oxygen upstream before process gas
• Helium leak check the assembled joint, then the inboard and across-seat envelope
• Record the serial number, leak result and gas service in the system dossier

Ordering and configuration

Quote the model code and the options below. Where a gas is corrosive or pyrophoric, include the concentration so the diaphragm or seat alloy can be matched to the service.

Related models and alternatives

Other valves in the Bellows Sealed Valves family and adjacent groups that may suit a different Cv, pressure or port requirement.

VB8

Bellows Sealed Valves

VB8 Low Pressure Bellows Sealed Valve

• Port size1/2, 3/8, 10mm, 12mm
• Max. pressure500 PSI
• Cv0.80

View specifications →

VB4

Bellows Sealed Valves

VB4 Low Pressure Bellows Sealed Valve

• Port size1/4, 3/8, 6mm, 8mm
• Max. pressure500 PSI
• Cv0.3

View specifications →

VMU

Metering & Needle Valves

VMU High Purity Metering Valve

• Port size1/4, 1/2, 6mm
• Max. pressure700 PSI
• Cvmetering stem 0.019

View specifications →

Frequently Asked Questions