APPENDIX GCompressed Gas Cylinders
Compressed gases are used throughout the College of Environmental Science and Forestry. Regardless of the use or content of the cylinder, compressed gas cylinders represent a serious health and safety hazard. An improperly handled cylinder may result in serious injury or death through the sudden release of its contents. A flammable gas suddenly released into an area may cause a fire and explosion. Toxic or reactive gas suddenly released into an area may cause asphyxiation. Even a “harmless” gas could create such high concentrations that it would be impossible to breathe. Also, a compressed gas cylinder is a potential projectile or bomb if not properly secured.
A. General Guidelines for Handling Compressed Gases
These guidelines must be followed for all compressed gas cylinders used at ESF.
- Cylinders must be firmly secured at all times using straps, chains, or clamps. Cylinders are to be located away from traffic areas and clearly labeled as to their contents.
- The correct cylinder valve is to be used for the particular gas in use. Valve threads may be right-handed for non-fuel gases and left-handed for fuel gases. Cylinders not in use must be capped.
- Transport gases with an approved cart or hand truck. Never roll or scoot a gas cylinder. Do not lift cylinders by the cap.
- Keep an unregulated cylinder valve closed at all times. Open the main valve only to the extent necessary and regulate the gas flow using the regulator. Ensure adequate ventilation and precaution when using hazardous gases. Report leaking gas cylinders to University Police (x6666) and Laboratory Director.
- All cylinders must be clearly marked with the name of the contents.
- Do not use oil, grease or lubricants on valves, regulators or fittings.
- Do not attempt to repair damaged cylinders or to force frozen cylinder valves.
- Before moving the regulator, close cylinder valve first, then release all pressure from the regulator.
- Cylinders that are not necessary for current needs shall be stored in a safe location outside the laboratory work area.
- Purchase only reusable/refillable cylinders.
B. Flammable Gases
Special care must be taken when flammable gases are used in confined spaces.
- No more than two cylinders should be manifolded together. Several instruments or outlets are permitted for a single cylinder.
- No more than one cylinder of a highly flammable gas may be in a room without specific review by the Laboratory Director and Chemical Hygiene Officer.
- Cylinder size is limited to 300 cubic feet.
- Valves on all flammable gas cylinders shall be shut off when the laboratory is unattended.
C. Attaching Regulators
- Cylinder throats and surfaces must be clean and tightly fitted. Do not lubricate.
- Tighten regulators and valves firmly with the proper sized wrench. (Do not use pliers. They many damage the nuts.) Do not force fittings to ensure a tight seal.
- Open valves slowly. Do not stand directly in front of gauges (the gauge face may blow out). Do not force valves that “stick.”
- Check for leaks at connections. Leaks are usually due to damaged faces at the connections or improper fittings. Do not attempt to force an improper fit. (It may only damage a previously undamaged connection and compound the problem.)
- Valve handles must be left attached to the cylinders.
- The maximum rate of flow should be set by the high-pressure valve on the cylinder. Fine-tuning of flow should be regulated by the needle valve.
- Shut off cylinder when not in use.
D. Leak Testing
Cylinders and connections should be tested by SNOOPä or a soapy water solution. Test the cylinders before regulators are attached and again after the regulators or gauges are attached.
E. Empty Cylinders
- Must be marked empty.
- Must be returned promptly.
- Must have valve safety caps replaced.
F. Cryogenic Liquids
- Store in well-ventilated area to prevent displacement of air.
- Use only approved storage vessels having fittings to relieve pressure
- Always wear eye protection, preferably a face shield.
- Always wear hand protection, preferably heavily insulated gloves.