Signs of a backfire:
- A bang is heard.
- The flame is extinguished.
- The body of the torch heats up.
Causes of a backfire:
- A dirty nozzle.
- The nozzle is held too close to the material.
Oxygen cannot burn alone.
- When cutting with a torch, the inner white cones of the flame should not touch the metal being cut. The distance between the nozzle and the metal will depend on the thickness of the metal and the size of the nozzle being used.
- The wearing of the correct safety clothing must be enforced at all times i.e. leather gloves, safety goggles, leather aprons and leather shoe spats if required, spats to be used if adequate protection is not provided by the safety shoe or boot being used.
- Never use old oil drums or hollow containers as a support when cutting with a torch. It may fill with a mixture of the cutting gases and explode like a bomb when ignited.
- Under no circumstances must a gas lighter be used or carried when using oxy-acetylene equipment.
In Shafts:
- Where practically possible, gas cylinders must be secured in an upright position in the bottom deck and an attendant must always be available at all times when cutting is done.
- A fire extinguisher must be available on the conveyance at all times when cutting is done.
Reduction Works:
When working over conveyor belts, rubber-lined chutes or any inflammable materials, great care must be exercised to catch the molten metal and off-cut metal. No hot metal or fragments must be allowed to fall on the conveyor belts or any inflammable parts.
- While working over conveyor belts, rubber-lined chutes or any inflammable materials, great care must be exercised to catch the molten metal and off-cut metal. No hot metal or fragments must be allowed to fall on the conveyor belts or any inflammable parts.
- When cutting material that contains pyrite or fragments of pyrite, the area must be well ventilated.
- Because extra long hoses are used for cutting, care must be taken that they are properly suspended from the top of buildings to the cylinder trolley. Always make sure that there is a certain amount of slack in the hoses.
- Where possible keep the trolley with cylinders out of the direct rays of the sun.
- Do not use the equipment where inflammable chemicals or cyanide are being used or stored
Storage And Handling Of Oxy-acetylene Equipment And Gas Cylinders
Cylinders are to be stored in a safe, dry and well-ventilated place prepared and reserved for the purpose, i.e. storage cages or demarcated areas.
- Cylinders are to be secured by means of a safety chain in an upright position.
- Flammable substances such as oil and volatile liquids must not be stored in the same area.
- Cylinders must not be stored in places where they can be knocked down or damaged.
- Oxygen cylinders must not be stored within 6m of cylinders containing flammable gases or to highly combustible materials.
- If cylinders cannot be stored 6m apart then they should be separated by a fire resistant partition at least 1,6m high, having a fire resistance rating of at least 30 minutes.
- “No Smoking” and “No naked lights” signs must be displayed.
- Cylinders should be protected from the elements i.e. sun and rain.
- Never permit cylinders to come in contact with electric apparatus or circuits.
- Storage facilities should be planned so empty and full cylinders are segregated.
- Do not store equipped cutting torch trolleys in close proximity or vicinity of other full acetylene cylinders.
- Always ensure that the acetylene and oxygen cylinders are properly closed and no leaking of gas is possible.
Transporting And Moving Gas Cylinders
Under no circumstances will gas cylinders be transported inside a vehicle or car.
- Gas cylinders must be transported in open back vehicles and where practically possible in an upright position.
- Where possible moveable storage cages equipped with chaining devices will be designed for the transportation of gas cylinders.
- During transportation ensure that cylinders are not subjected to abnormal mechanical shocks, which may cause damage to their valves or their safety devices or to the cylinders themselves.
- Cylinders must never be dragged; they must be moved in trolleys or material cars designed for the purpose and in an upright position.
- Never lift a cylinder by the cap or guard, except with an approved cylinder cart designed for this purpose.
- Drivers transporting gas cylinders should be made conversant with all the safety requirements.