Compressed Gas Cylinders & Valves
Compressed gas means any mixture or any
material in gaseous form whose absolute pressure exceeds 275.8 kPa at 21 Degree
C or an absolute pressure exceeding 717 kPa at 54 deg C or both, or a liquid
who absolute vapor pressure exceeds 275.8 kPa at 37.8 deg C.
Compressed gases are toxic, inert, corrosive,
flammable or oxidizing. If an inert gas leaks, it displaces air and creates an
oxygen deficit environment. Toxic gases make the atmosphere poisonous.
Flammable or reactive gases cause explosive fire. The high pressure of the gas
or build up of further high pressure can break the cylinder or become a missile
if the cylinder valve breaks. Identifying and using good quality cylinders and
valves is necessary for proper storage or transport of the compressed gas and
to prevent accidents
Hazardous properties of industrial
gases
- High pressure – most of cylinder gases are under high pressure between 2000 psi to 3000 psi. Compressed cylinder gases are available up to a pressure rating of 7500 psi
- Extremely cold – gases like helium, hydrogen, carbon dioxide, nitrogen or oxygen are stored in cryogenic liquid form. The temperature of the liquid and vapor ranges from -109 deg F to -452 deg F. A build-up of high pressure may arise from the trapped evaporating liquid. A good quality valve and cylinder that sustains higher pressure can reduce the chances of an accident
- Inert gases like argon, CO2, helium and nitrogen may cause asphyxia. Proper ventilation at the place of storage along with 19.5% of oxygen ensures safe storage
- Oxidizers – oxygen and nitrogen oxide are the two industrial gases that do not burn, but do burn with explosive violence. Keep all organic material away from Oxygen, do not lubricate the valves and prevent spillage of liquid oxygen on surfaces
- Flammable – gases like propane, hydrogen, acetylene are highly flammable gases. Cylinders for storage of these gases should be carefully selected with valves that do not react with these heavy gases.
How to Store Compressed gas cylinder
- Compressed gas cylinders should be stored where the ambient temperature does not exceed 52 deg C. If the ambient temperature does exceed this temperature, there is a great probability of gas release in spite of the over-pressure protection device which is usually a valve
- The indoor areas used for storing compressed gas cylinders must be dry and well ventilated to prevent the buildup of gas vapors which may cause leakage of the gas and corrosion of the cylinder too
- For highly inflammable gases like oxygen, oils or grease should not be used for lubricating the valves as it could easily ignite and cause a major accident due to connection failure resulting in more release of oxygen
- If the compressed gas cylinders are stored outdoors, they should be placed on a raised, non-combustible platform and protected from the weather, dampness which may corrode the cylinder and cylinder valves
- Keep the valve closed when the cylinder is not in use
- Always store the cylinder in an upright position
- Use regulators, valves and other fitting that are designed for that gas, do not interchange
How to choose the right cylinder and
valves for compressed gases
Depending on the type of gas that is to be
stored, the choice of material for cylinder is to be made. Aluminum has
replaced all other material for making cylinders. Aluminum cylinders have a
special advantage of being lighter in weight, more durable, it is lower in cost
and is relatively easy to repair. Aluminum cylinders are widely used for
welding, beverages, oxygen therapy, industrial or specialty gas applications. A
wide range of high or low pressure and various sizes of aluminum compressed gas
cylinders for various purposes.
