Project Safety Procedure for Management and Control of Compressed Gas Cylinders

The purpose of this method statement is to provide guidance and recognition for the management, use and control of compressed gas cylinders on a construction project site.

Overall project manager have responsibilities for the implementation of this standard safety procedure.

Gas cylinders are hazardous because they are sealed pressure vessels in addition to the hazards from  their  contents.

If mistreated or heated cylinders can rupture and become missiles traveling at high speed for up to 100m.

The released contents may also create hazards if flammable, toxic or oxidizing. Damaged or poorly closed valves may leak the contents into the local atmosphere creating environmental hazards.

Heavier than air gases leaking from cylinders may accumulate in basements or drainage systems where, in addition to toxic or flammable hazards, the reduction in oxygen levels may become a cause of suffocation.

An assessment of risk should be made considering as appropriate the storage, use and transport of such substances.

The following risk checklist provides details of the possible risks, which should be considered in the cylinder handling risk assessment.

Employee Training Handling Gas Cylinders

All personnel involved in the storage, transportation and use of gas cylinders should receive training suitable for the type of work in which they are engaged the minimum training should cover:

i. Identification of types of gas cylinders.

ii. Characteristic smells.

iii. Potential hazards of the relevant gases.

iv. Cylinder content identification.

v. Supplier’s information relating to storage/handling

vi. Site safety regulations.

vii. Sitting of statutory notices.

viii. Emergency procedures

ix. Using a Fire Extinguisher

Gas Cylinder Storage Instructions

Compressed gas bottles especially oxygen and acetylene cylinders must be stored in a well ventilated area. Chained alright.

The area is to be clearly sign posted; No Smoking and No Naked Flame.

Bottles are to be stored in an upright position and secured against accidental dislodgement.

Oxygen and acetylene bottles are to be separated by a flame proof wall or by distance of at least 3 meters.

Empty cylinders are to be marked accordingly and separated from full cylinders. Sign Posted.

Control Measures in Handling of Compressed Gas Cylinders

Where cylinders are to be kept for an appreciable length of time, facilities should be provided to ensure that they cause no hazard to workers or public in the area.

Cylinders should be stored in a well-ventilated area – preferably in open air but protected from the weather. Chained upright in a Vertical Position. Ensure protection caps are in place or all cylinders.

The store should be away from fire risks and sources of heat and ignition. Nothing else should be stored in the area.

The cylinders should be stored upright on a firm, level, well-drained surface free from hollows and cavities. All long grass, weeds etc. should be removed.

Cylinders should be secured so as they are prevented from falling over, when in storage or use.

Different type of cylinders should be segregated within the store according to type and whether full or empty. (Sign Required)

Oxygen and oxidizing gases should be separated from flammable gases by 3m or by a fire resistant partition.

No electrical apparatus should be installed within a cylinder store unless it is constructed to a suitable standard for the associated hazard.

No cylinder should be used in a storage area.

Appropriate warning signs “HIGHLY INFLAMMABLE”, “NO SMOKING”, “FULL/EMPTY” etc. should be displayed.

Suitable fire fighting apparatus should be situated adjacent to the store. Typically dry powder fire extinguishers. These should be inspected and maintained at intervals not exceeding 1 year.

Where cylinders are required to be stored in a compound this should be located not less than 3 meter from any building, site or public access road.

The compound fences should be a minimum of 2 meter high, and it should have two means of escape, with the gates opening outwards.

Where it is necessary to take precautions against vandalism or theft, suitable protection cages should be used.

Each cylinder should be adequately marked to include the manufacturer’s mark and serial number, together with an indication of the specification to which the cylinder is constructed and its year of manufacture.

A date of test and pressure test, together with weight of cylinder and the name of the product should be displayed.

Sealant tape to effect a seal between the bottle and regulator valve should be green Teflon tape. White Teflon tape may have residual flammable solvent left on the tape during extrusion, which result in causing a fire or explosion.

All Cylinders must be checked for leakage weekly using a soapy solution (e. Dishwashing liquid and water.)

Transportation on Site

When gas cylinders are to be transported they should be protected from physical damage and the consequences of any leaks that may occur minimized. Must be secured, also use wedges.

Move cylinders using chains by hand in proper cylinder trolleys where the cylinder is secured in the trolley.

Take great care when lifting cylinders, as they can be very heavy and awkward to handle.

Transportation by Road

When transporting cylinders by road they should preferably be moved in an open vehicle.

If this is not possible and cylinders should be carried in vans or cars the vehicle should be ventilated by leaving windows open at all times. Toxic gases should not be carried in an enclosed vehicle.

Before moving any cylinder remove all attached equipment including regulators.

Cylinders should be properly supported and secured within the vehicle so they cannot move during the journey. They should be totally within the vehicle and protected form impact.

Cylinders should be checked to ensure that the valves are closed and there are no leaks.

The vehicle should be equipped with a suitable fire extinguisher. Typically dry powder.

There should be no smoking within the vehicle whilst carrying cylinders.

The driver of the vehicle should be conversant with the load and have written information on the hazards and the action to be taken should any problems occur.

The driver should also have training in the operation of the fire extinguisher and any other safety equipment carried.

Cylinders should be removed from the vehicle at the end of the journey and care should be exercised if the vehicle is being parked for any time during the journey.

Cylinders should not be used when inside a vehicle unless the vehicle has to be specifically designed or adapted for the purpose.

LPG and acetylene cylinders should always be transported in the upright position to prevent leakage of liquid gas.

Thermal Cutting Precautions Using Gas Cutting Technique

Visually inspect the equipment before each use and if it is found to be contaminated with oil or grease it is not safe until properly cleaned. Wiping down with a rag will not satisfactorily remove oil or grease.

Do not use worn hose or equipment that are in need of repair or damaged. Always inspect hoses and equipment for leaks prior to use, particularly when the cutting system is used in confined spaces.

Be sure to keep a clear space between the cylinders and the work, cylinders should always be positioned for quick access in case of a leak or emergency.

Before connecting a regulator to a cylinder valve always “crack” the cylinder valve to blow out the valve opening of dust or dirt that otherwise might enter the regulator.

Attach regulators to cylinder valves. Use a proper wrench and do not over-tight. Ensure Flash back arrestors are in place.

Always ensure the proper torch head is attached to the torch barrel, inspect the O-rings for damage, and ensure that the correct cutting tip is in place and clean.

Always inspect the twin cutting hose sections, if the twin hose has separated, rejoin the hose with a good grade of hose clip with a minimum spacing of six inches. Avoid clipping any section that shows sign of damage. Hoses should not be longer than 15m in length.

Back off the adjusting screw fully on the regulator anti-clockwise before you open the cylinder valve.

Open the cylinder valve slowly.

Open acetylene valve on mixing barrel ¼ -1/2 turn.

Charge the line with 6 psi acetylene, turn off valve at the mixing barrel.

Turn off cylinder valve and watch gauges on the regulator. This procedure will tell you if you have a leak in the system. Repeat this procedure on the oxygen valve using 30-spi.

If no leaks are found, open the oxygen valve all the way and the acetylene valve ¼ – ½ If leaks are found, determine the severity and notify the supervisor for replacement of bad parts.

Acetylene gauge pressure should never be greater that oxygen gauge pressure to the torch and when finished always turn the acetylene off at the torch before turning off the oxygen.

A striker only use to light the torch. Open flame, lighters or matches cannot be used to light the torch because of the possibility of burns and explosions. Disposable cigarette lighters should not be on your body.

Do not let acetylene or oxygen escape near any possible source of ignition. Accumulations of acetylene above its lower explosive limit may explode if ignited.

Always stand to the opposite side of the regulator when cracking or opening the cylinder valve.

Should the flame go out and the flame burn back into the torch, producing a sudden hissing or squealing noise, immediately shut off the torch. The flame is capable of burning through the torch and may cause injury.

If rapid loud popping sounds occur while igniting the torch, adjustment to the oxygen or acetylene may be necessary.

When returning to the same job and location the next day or having left the job for more than two hours, always inspect the cutting system for any leaks or changes prior to using the equipment.

Leather gloves and goggles must be worn. Flip type burning lenses may be worn but do not offer as much side protection as goggles. A #4 or #5 lens is acceptable.

When commencing work always lay the oxygen and acetylene hose in a path that best protects it from damage.

Oxygen and acetylene cylinders should always be removed from designated confined space area whenever the job is complete or whenever the job is vacated for more than one hour without proper observation.

If some one suspects that a leak has occurred in a designated confined space while unattended, proper gas detection equipment should be obtained to test the confined space prior reentering.

When the job is completed turn off cylinder valves (fuel supply firs), bleed off remaining fuel and oxygen from hoses, turn off valves on mixing barrel clockwise and back off pressure regulating screws counter clockwise.

Remove regulators, put plastic caps back on regulator connection and install cover caps on the tank.

Make sure fire fighting equipment (fire extinguisher or water) is present. Wet down the area if necessary prior to burning.

Keep your work area clean of anything that will burn. Erect barricades to protect flammable material that can not be removed from the area.

A fire watch may be necessary if burning takes place in crucial areas.

When burning above a walkway or work area, place a “Men working above” sign at entrances.

Fire Precaution For Use & Handling of Gas Cylinders

Fire extinguishers should be correctly sited, inspected and maintained.

Fire extinguishers recommended are Carbon Dioxide or Dry Powder.

Keep Cylinders away from combustible materials.

If a leak occurs and does not ignite and the cylinder is not getting hot, take the following action immediately:

i. Close the valve

ii. Remove source of ignition, enforce no smoking

iii. Remove cylinder to fresh air

iv. Ventilate the work area

v. Ensure Flash Back Arrestors are in place.

If the cylinder leak has ignited:

i. Evacuate the area

ii. Inform the Fire Brigade

iii. Spray water on the cylinder from a protected position

iv. Remove other cylinders to a safe place if it can be done without risk.

v. Inform local Safety Adviser.

vi. Ensure Flash Back Arrestors are in place.

Checklists for Compressed Gas Cylinders Handling

a) Are cylinders correctly stored in a suitable compound? Upright and sealed

b) Are the appropriate signs displayed?

c) Are suitable vehicles being used for transportation?

d) Are vehicles correctly equipped?

e) Are drivers in possession of relevant information and training?

f) Do all fittings meet the British Standard? Best International Practices

g) Are all fittings in good condition, correctly connected and suitable for the task?

h) Are fire and emergency procedures formulated?

i) Are extinguishers available for use, storage and transport?

j) Have all staff involved with gas cylinders been given appropriate instruction, information and training?

k) Are Flash Back arrestors installed at gauges and secure?

l) As minimum one Flash Back Arrestor at cylinder