Cylinders and containers must always be moved carefully. Mishandling that results in a damaged valve or ruptured cylinder can expose personnel to the hazards associated with these gases. In addition, most gas cylinders are heavy and bulky. A cylinder striking someone or pinching a finger, toe, or other extremity is a common cause of injury. For these reasons, all cylinder handlers must always wear certain minimum personal protective equipment prescribed by OSHA.
Before moving the cylinder to the storage area or point of use or before returning the cylinder to the supplier, ensure the following:
While moving full or empty cylinders:
After moving a cylinder to its point of use, secure the cylinder in place. Use cylinder stands, clamps, or other securing devices recommended by your supplier.
Storage of compressed gas cylinders and cryogenic liquid cylinders is governed by codes of the National Fire Protection Association (NFPA). Local codes may also apply. Know and obey codes governing storage at your location.
In general, store cylinders so they can’t be easily toppled over. Remember, danger exists not only from accidental release of gas by cylinders damaged in a fall but also from their striking someone and causing injury. Store cylinders upright in compact groups, interlocking them so that each cylinder physically contacts those around it. Do not stand cylinders loosely or in a haphazard manner. A single cylinder that topples over can create a domino effect causing other cylinders to fall. Single cylinders should be secured in place or on a cylinder cart so they can’t be easily knocked over. Keep stored cylinders out of high traffic areas. Do not store them near the edges of platforms. Avoid storage in areas where there are activities that could damage or contaminate the cylinders. Electric arc welding can destroy the integrity of cylinder metal if a welder carelessly strikes an arc on a cylinder. Overhead hoists can drip oil or grease on cylinders, contaminating them. Never store cylinders with flammable materials.
Observing a few simple rules when opening and closing valves can prevent damage to valves and equipment and add years of useful service life to the valves. The proper way to open any cylinder valve is to first crack the valve, then open it slowly by turning the handle or stem counterclockwise (see Figure 1). This allows equipment to gradually adjust to full pressure. Stop turning as soon as there is any resistance. Turning the valve handle or stem too far in the open position can jam the stem causing damage and leaks and preventing later closure. Likewise, overtightening when closing a valve can damage or permanently distort the seat and result in leakage.
Personnel responsible for receiving cylinders should perform an external inspection on all packages before moving them to the point of use or to the storage area. Basic guidelines for performing this inspection are as follows:
After completing the external inspection, proceed as follows:
|Packed Stem Valve
|30 to 40 ft-lb
|Diaphragm Stem Valve
|85 to 96 ft-lb
|Pressure Seal Valve
|60 to 85 ft-lb
|20 to 25 ft-lb
|CGA Cylinder Connection
|CGA Cylinder Connection
|Acetylene (approximately 10 ft3)
|Acetylene (between 35 and 75 ft3)
|Helium (less than 3,000 psig)
|Acetylene (over 50 ft3)
|Helium (greater than 3,0000 psig)
|Air, Breathing Grade
|Air, Industrial Grade
|Nitrogen (less than 3,000 psig)
|Argon (less than 3,000 psig)
|Nitrogen (greater than 3,000 psig)
|Argon (greater than 3,000 psig)
|Nitrogen, Cryogenic Liquid
|Argon, Cryogenic Liquid
|Oxygen (less than 3,000 psig)
|Oxygen (greater than 3,000 psig)
|Carbon Dioxide, Refrigerated Liquid
|Oxygen, Cryogenic Liquid