Developed specifically for mass spectrometry inlet service, perhaps the most critical application for such a valve, and also suitable for other applications where long-term stability is required
The Mechanism range of stainless steel needle valves, developed by Chell Instruments, provide the finest gas flow control over typical ranges of 0-20 and 0-500 std.cm3min-1 air at 1bar differential pressure.
Designed for use in pressure or vacuum applications, they are ideal for gas analysers, chromatographs and mass spectrometers - in addition to any application where fine control is required.
The valve's opening characteristics are extremely smooth, says Chell, preventing bursts of gas which disturb delicate or ultra high vacuum instrumentation.
Repeatability is also said to be good, and the valves are available with a useable turns counting dial so that flow settings may be repeated time and time again.
Construction is in stainless steel with either Viton or Perlast seals for the best corrosion resistance.
Vacuum rated valves are leak tested on a helium mass spectrometer to <1x10-8mblsec-1 and their shut-off achieves the same specification.
Valves are available with 1/16in single ferrule or 1/8in twin ferrule compression fittings and additionally, vacuum models may have NW10KF fittings.
The Mechanism valve was developed specifically for mass spectrometry inlet service, probably the most critical application for such a valve but is eminently suitable for many other critical applications where long-term stability is required.
