Gas Handling

Updated by Janet 9/17/2014

We use many compressed gas cylinders in our labs: KrF/Ne premix for the excimer laser, high purity He to purge the excimer laser and to refill the CCR compressor, regular grade He for leak detections, nitrogen to vent the vacuum chambers, high purity O as a deposition gas, Ar or Ar/O mix as a sputter or PLD gas, and high pressure nitrogen to run the MMR cryostat. And others! You should understand the safety issues associated with the gases themselves (toxicity, reactivity) and with the fact that they are at high pressure. Understand how to identify and use regulators, gas lines. Know where to order them.

A gas cylinder should ALWAYS carry an accurate label that specifies FULL, IN USE (with pressure and date if possible) or EMPTY. This saves an enormous amount of time. Use masking tape to label if you can't find the official label, and remove old labels.

All gas cylinder MUST be secured with a strap to a bench or a wall at all times. Do not strap more than about 5 cylinders together. This is extremely important. Gas cylinders are basically torpedoes. NEVER let them drop. Strap cylinders to the gas cart to wheel them around.

Gas cylinders obtained from vendors are subject to monthly rental, so send them back promptly to the vendor who supplied them. Usually the vendor name is stamped on the cylinder neck. A few gas cylinders belong to us (no stamp on the neck and supposedly labeled as ours) and we do not pay rental on them, and we can get them refilled by Industrial Welding Supply. As of 2014, we have one standard compressed N2, one standards compressed He and one standard compressed O2 cylinder.

• Most gases come from Industrial Welding Supply,880 NE Circle Blvd, Corvallis, OR 97330; (541) 752-8686 - Christine (Also Albany & Salem offices)

Call the Corvallis office to order or to schedule pickup. IWS delivers to OSU on Tuesdays. The delivery person comes to the lab BUT MUST BE LET IN because he/she MUST secure the new cylinders and the pickup cylinders must also be secured. Someone must sign for the cylinders upon delivery. (IWS cylinders are stamped with the IWS name, but because IWS was at one time the distributor for BOC specialty gases, sometimes BOC sylinders come from IWS.)

• We also buy the KrF premix for the PLD laser from Airgas in Corvallis (since 2014). Previously from Linde (formerly Spectra gas). Airgas also has other specialty gases, e.g. high pressure (10,000 psi) N2 cylinders for the MMR cryostat, 5N He for the closed-cycle fridge compressor and the PLD laser. Call the company to schedule order and pickup.

• We can obtain some gases from the OSU Chemistry Department (helium, oxygen).

• Other vendors: PRAXAIR (Eugene and Salem); BOC specialty gases

Here is a good resource about how to connect gas bottles and the safety issues associated with cylinders. It also has information about different types of connectors: all gas bottles and regulators have standardized fittings that are particular to particular gases. Fittings are labeled by CGA-number. CGA=compressed gas association. CGA-580 is used for inert gases. Oxygen fittings have left handed threads (puts a high barrier to your accidentally venting highly reactive gas). A list of CGA fitting can be found at the CONCOA site.

Victor SG4-580 high pressure gas regulator victor_gas_regulator_sgseries.pdf