Introduction
This chapter contains guidelines and requirements for the safe use of compressed gases. It covers the use high-pressure gas cylinders.
Hazards
All gases must be used in a manner that will not endanger personnel.
Hazards associated with handling and use high-pressure gases include the following:
- Injuries caused by flying objects accelerated by an explosion or pressure release;
- Secondary accidents such as falls or electrical shocks;
Relief Valves Required
All systems, system components, and piping subject to over-pressures must be equipped with relief devices.
Cylinders
Only cylinders meeting Department of Transportation (DOT) regulations may be used for transporting compressed gases.
Each cylinder must bear the required DOT label for the compressed gas contained, except under certain specified conditions set forth in DOT regulations.
It is illegal to remove or to change the prescribed numbers or other markings on cylinders – do not deface, cover, or remove any markings, labels, decals, or tags applied or attached to the cylinder by the supplier.
Each cylinder must carry a legible label or stencil identifying the contents.
Do not repaint cylinders unless authorized by the owner.
Compressed-gas containers must not contain gases capable of combining chemically, nor should the gas service be changed without approval.
Cylinder Handling
Compressed gases should be handled only by experienced and properly instructed personnel. When in doubt about the proper handling of a compressed gas cylinder or its contents, consult your supervisor.
Compressed gas cylinders are dangerous when handled incorrectly.
Always assume that a cylinder is pressurized. Handle it carefully.
Never throw, bang, tilt, drag, slide, roll, or drop a cylinder from a truck bed or other raised surface.
If a cylinder must be lifted manually, at least two people must do the lifting.
Because of their shape, smooth surface, and weight, gas cylinders are difficult to move by hand. A truck or an approved cylinder handcart must always be used to move a cylinder.
If damaged, a cylinder can cause severe injuries, including lung damage from inhalation of toxic contents and physical trauma from explosion.
A pressurized gas cylinder can become a dangerous projectile if its valve is broken off.
When a cylinder is not connected to a pressure regulator or a manifold, or is otherwise not in use, it is extremely important that the cylinder valve be kept closed and the safety cap be kept in place-the cap protects the cylinder valve (do not lift cylinders by their caps).
Cylinders containing compressed gases should not be subjected to a temperature above 125 degrees F. Flames must never come in contact with any part of a compressed gas cylinder, pressure apparatus, hoses, etc.
Do not place cylinders where they might become part of an electric circuit.
Never attempt to repair, alter, or tamper with cylinders, valves, or safety relief devices.
Working With Gases
Always identify the contents of a gas cylinder before using it. If a cylinder is not clearly labeled, alert your supervisor.
Before using a cylinder, be sure it is properly supported with two metal chains or the equivalent to prevent it from falling.
Keep removable keys or handles on valve spindles or stems while cylinders are in service.
Connections to piping, regulators, and other appliances should always be kept tight to prevent leakage. Where hose is used, it should be kept in good condition.
Before a regulator is removed from a cylinder, close the cylinder valve and release all pressure from the regulator.
Before returning an empty cylinder, close the valve and replace the cylinder-valve protective cap and outlet cap or plug, if used.
