Safety Work Instruction for Compressed Gas

By : KOMARUL FAUSIYAH

Procedure

• All compressed gases should be handled in accordance with the safe practices applicable to the particular compressed gas. All compressed gas cylinders subjected to physical damage should be referred to Safety Department for evaluation prior to further usage.

Identification …

1. Compressed commercial gases are defined as follows ; Combustible non-liquefied gases. Combustible liquefied gases. Non-combustible, non-liquefied gases. Non-combustible, liquefied gases

2. Flammable gases are usually contained in a red painted cylinder.

3. Non - flammable gases are usually contained in a green painted cylinder.

Identification

• The following is a list of typical compressed gases :

– Acetylene - Flammable– Hydrogen - Flammable– Oxygen - Non-flammable (It will explode

when brought into contact with oil, grease and other organic materials).

– Argon - Non-flammable– Freon - Non-flammable– Nitrogen - Non-flammable

Transportation and Handling

• Do not abuse or miss-handle gas cylinders. They should never be dropped, permitted to strike each other, or to strike any other object.

• Rope or chain slings should never be used to carry cylinders. If necessary to hoist, use a proper designed basket.

• Empty cylinders should be labeled “empty” and segregated from full cylinders.

• Protecting valve caps should always be used when valves on cylinders are not in use.

Storage

• Cylinders must be stored on a upright (standing) position and tied or otherwise made secure.

• Cylinders should not be stored near highly flammable substances.

• Do not store cylinders near aisles, or in locations where moving objects may strike or fall on them.

• Cylinders containing acetylene should always be stored in a separate group, never with store together with oxygen cylinders.

Usage …

Never mix gases in a cylinder. Never attempt repairs to valves or gauges, return them

to the Maintenance Department. Make sure that the threads on regulators correspond to

those on the cylinder valve outlet. Never force connections that do not fit. Different

threads and thread sizes are used on cylinders to prevent interchange of equipment.

Cylinder valves should be opened slowly to avoid pressure surges

Usage …

When “cracking the valve”, opening the valve for an instant to clear the opening for dust or dirt, the following precautions should be taken ;1) Never open a valve near a flame or other sources of ignition.

2) Always point the valve opening away from the body, but not toward anyone else.

3) Compressed gas cylinders containing highly toxic gas should not be opened to atmosphere.

Never permit the gas to enter a regulator suddenly. Open all valves slowly.

Before removing regulator from cylinder, close the cylinder valve and release all gas from the regulator.

Usage …

Never attempt to stop a leak between a cylinder and a regulator by tightening the adjusting nut, unless the cylinder valve has been closed.

Do not allow sparks, molten metal, electric current, excessive heat or flames to come in contact with the cylinder, the hose or the regulator.

Do not use oil or grease on attachments for oxygen cylinders. (BEWARE DANGER OF EXPLOSIVE).

When valve protection hoods become frozen or filled with ice, let them melt out in a warm room. Never use steam or any other sources to melt them out.

Usage

Cylinders should never be used for any purpose other than containers for the particular gases for which they were designed.

Cylinders must be used in an upright position, they must be secured to a substantial structure to prevent their falling over.

Never use compressed gas to dust off clothing. Cylinder valves should be tightly closed when not in use or

empty. Never use flame to detect gas leaks. Use soapy water. Cylinders with leaking valves should be removed to a safe

location and tagged as having a defective valve. Oxygen should never be used as a substitute for air and

should always be designated by its proper name.

Equipment

• Combustible gas regulators, hose or other appliances should never be interchanged with similar equipment intended for use with other gases.

Compressed Gas Cylinders

Compressed gas cylinder safety is insured by the supplier through his adherence to regulations set forth, and by his supplying cylinders with specific valves, labels, and/or markings in accordance with recognized standards. It is mandatory for the supplier to ship cylinders manufactured, hydrostatic test certificate, inspected and filled in conformance with the regulations and to used approved safety devices. This procedures outlines the basic requirements for the handling, storage and used of compressed gas cylinders.

Handling …

• Cylinder valve shall be closed before cylinders may be moved.

• Cylinder regulators shall be removed and valve protection caps screwed down hand tight before cylinders may be moved, except when cylinders are mounted on a truck designed for movement with regulators assembled to cylinders.

• Cylinders should be manually moved only by means of a suitable hand truck. Where this is impractical, cylinders may be hand rolled in the vertical position. Never drag, drop or slide a cylinder.

Handling …

• For in-plant transport by motor vehicle, cylinders must be carried in the vertical position. Cylinders shall be positively secured against toppling, rolling about and sliding while in transport.

• In lifting and lowering cylinders with hoists, cranes, etc., a cradle boat or similar device must be employed. Slings or electric magnets shall not be used. Never use valve protection caps for lifting cylinders.

Handling

• Carelessness in the handling of an empty cylinder could result in its being mistaken for a full cylinder. The connecting of an empty cylinder to a high pressure system could cause foreign matter to back up into the cylinder, resulting in all the attendant hazards of suck-back and possible violent reaction within the cylinder. Therefore, it is necessary to keep empty cylinders carefully segregated from full cylinders. Always handle empty cylinders with the same care afforded full ones, because an “empty” cylinder may contain a pressure greater than 1,000 psig.

• Carefully protect cylinders from impact and friction.

Usage …

• For purposes other than certain Engineering Test applications, automatic pressure regulators with flow control valves shall be used on cylinders. Do not force a fit between a regulator and a cylinder outlet. A poor fit may indicate that the regulator is not intended for use on the gas chosen. Cylinder threads vary according to the kinds of gases the cylinders are intended for.

Usage …

• Knowledge of Properties :1. It is essential that personnel be aware of the

hazardous properties (flammability, toxicity, corrosiveness, and chemical effects) of the gas they are to use. These properties may vary according to how the gas is used. For example : In a hood with an open flame, the flammability of carbon Monoxide might be a major hazard, while in using Carbon Monoxide as a reactant in another location, leakage, and therefore toxicity, may be the major hazard

2. Only a very small concentrations are necessary to create flammable mixtures of the liquefied petroleum gases such as butane and propane. Acetylene, Carbon Monoxide, Ethylene Oxide, Hydrogen, and Hydrogen Sulphide form explosive mixtures with air under a wide variety of conditions.

3. Construction materials should be chosen to avoid the possibility of equipment failure through the action of a corrosive, and avoid the possible formation of hazardous compounds, such as Acetylides formed by the reaction of copper with Acetylene or gases containing Acetylene as an impurity, or the possible formation of fulminates when Mercury is used in the presence of Ammonia.

4. It is advisable that an indicator be used to warn of hazardous concentrations of toxic gases. For example, strips of lead acetate paper can be hung in an area where hydrogen Sulphide is being used. While this gas has a disagreeable odor, it soon deadens the sense of smell, rendering the user incapable of detecting increasingly dangerous concentrations by odor.

Usage …

• When corrosive gases are being used, the cylinder valve stem should be worked frequently to prevent freezing. Corrosive gas regulators and valves should be flushed with Dry Air or Nitrogen after use. Such control devices should not be left on a corrosive gas cylinder unless it is in frequent use.

a) Do not completely exhaust empty cylinders. The cylinder should be considered empty while positive pressure (25 psig or more) still remains, in order to prevent suck-back and contamination. Failure to close the valve on an empty cylinder will allow air and moisture to be drawn into the cylinder as it “breathes” during temperature changes; an explosive mixture may build up if the gas is flammable; and an extremely corrosive condition will be created in cylinders containing Chlorine, Hydrogen Chloride, or other acid forming or corrosive gases.

b) Before making connection to a cylinder valve outlet, except that of a hydrogen cylinder, “crack” the valve for an instant to clear the opening of particles of dust and dirt which otherwise might impair the function of the regulator. However, do not crack hydrogen cylinder valves. Always stand to one side of the valve opening when cracking the valve.

c) After making connection, open the cylinder valve slightly at first then all the way. (Exception : Open acetylene cylinder valves no more than 1-1/2 turns. Never use acetylene at pressure over 15 psig) Stand to one side of gauge faces when opening valves.

d) Use only the hands, no tools, in opening and closing hand wheel type valves. Use only the special T - wrenches on acetylene cylinder valves.

d) Make pressure regulator connections with a regulator wrench. To prevent leakage, be sure the nut is pulled uptight. Never tighten a leaky regulator connection without first closing the cylinder valve.

e) After making connections to cylinders of flammable and toxic gases, test the connections for leaks with a non-fat soap and water solution or other leak test solution that is compatible with the gas to be used.

f) After each use of a cylinder, close the cylinder valve, relieving pressure on the regulator. Replace the valve protection cap immediately upon removal of the regulator.

g) Cylinders shall be positively secured in the vertical position, by means of iron or fabric strapping, chain, cable or rope.

Storage

• Full cylinders, except for working stocks at job sites, shall be stored in a designated location, with the various gases segregated as building markings direction.

• Empty cylinders shall be stored in a designated location, with the various gases segregated as building markings direction.

Thanks for Your Attention

Safety Is Start From Ourselves