Frequently Asked Questions
Common questions about UHP diaphragm valves, specialty gas compatibility, actuation, connections and documentation.
Specialty Gas Valve FAQ
What is a specialty gas valve?
A specialty gas valve is a shut-off, switching or flow-control valve built for high purity, corrosive, toxic or pyrophoric gases. Compared with a general industrial valve it uses low-inclusion stainless steel, a metal diaphragm or bellows seal, electropolished wetted surfaces, helium leak testing and cleanroom packaging.
Which valve type is best for UHP gas lines?
A UHP diaphragm valve is the standard choice: the metal diaphragm isolates the actuator from the gas path, internal volume is low, and there is no stem packing to outgas.
What is the difference between specialty gas and industrial gas?
Specialty gases are supplied at high purity or are reactive, corrosive, toxic or pyrophoric. Their delivery systems need far tighter leak, cleanliness and material controls than bulk industrial gases such as nitrogen or compressed air.
Do you offer manual and pneumatic versions?
Yes. Most valve families are available with a manual handwheel or a normally closed pneumatic actuator. Pneumatic versions generally carry a lower maximum pressure rating than the manual version.
What end connections are available?
VCR face seals, orbital butt weld, compression fittings and threaded or CGA/DISS cylinder connections, depending on the model.
What information do you need for a quote?
The gas list with concentrations, maximum and normal pressure, required flow or Cv, port size, preferred end connection, manual or pneumatic actuation, and any cleanliness or documentation requirements.
Are the valves helium leak tested?
Yes. Inboard and across-seat helium mass spectrometer leak testing is available, with per-valve records for qualified installations.
Can Valonix configure a complete gas panel?
Yes. Valve manifold boxes, valve manifold panels and automatic changeover systems can be configured from a P&ID, gas list and interlock philosophy.