The optimal design for a laboratory high purity and instrumentation gases supply installation is to store the gas cylinders outside the building in a safe, well-ventilated location and pipe the gases into the laboratory to the point of use. This maximises the space in the laboratory for the laboratory technicians, the analytical instrumentation and smaller calibration gas cylinders - things that really belong in the lab.
Design of such a gas supply system involves a first stage of pressure regulation using a wall-mounted gas supply panel for each required cylinder gas. This may either be of a single regulator design connected to a single gas cylinder or an automatic changeover unit, which is constructed from two regulators and can switch between an empty and a full cylinder as required. The gas pressure is reduced to approximately 1500 kPa (15 bar) for transmission into the laboratory using medium-pressure pipework.
At the laboratory bench where the analysers are mounted, instrumentation gases such as Helium 5.0 grade, Argon 5.0 grade and Zero Air are required. The medium-pressure pipework feeds into a bank of point-of-use regulators which perform the second, finer, stage of pressure regulation to deliver the gas to the instrument at between 2 and 20 kPa, as required.
Application examples
EM55-1 for FTIR purge gas - one tapping point
- Nitrogen 5.0 grade
EM55-2 for ICP-AES - two tapping points
- Argon 5.0 grade
- Nitrogen 5.0 grade
EM55-2 for GC-MS - two tapping points
- Helium 5.0 grade
- Nitrogen 5.0 grade
EM55-3 for GC-FID use - three tapping points
- Helium 5.0 grade
- Hydrogen 5.0 grade
- Zero Air
EM55-4 for maximum flexibility in general purpose GC and laboratory applications - four tapping points
- Helium 5.0 grade
- Hydrogen 5.0 grade
- Nitrogen 5.0 grade
- Zero Air