Part 1. Preparation and safety
Objective
- Use an oxyacetylene torch for heating.
Personal safety
Whenever you perform a task in the workshop you must use personal protective clothing and equipment that is appropriate for the task and which conforms to your local safety regulations and policies. Among other items, this may include:
- Work clothing - such as coveralls and steel-capped footwear
- Eye protection - such as safety glasses and face masks
- Ear protection - such as earmuffs and earplugs
- Hand protection – such as rubber gloves and barrier cream
- Respiratory equipment – such as face masks and valved respirators
If you are not certain what is appropriate or required, ask your supervisor.
Safety check
- Oxygen and acetylene cylinders must be securely stored in an upright position.
- An oxyacetylene torch can produce a large amount of heat. Be aware that any objects you direct the flame towards will become hot.
- Always have a suitable fire extinguisher near your work area.
- Do not use an oxyacetylene torch near any flammable materials.
- Make sure that you understand and observe all legislative and personal safety procedures when carrying out the following tasks. If you are unsure of what these are, ask your supervisor.
Points to note
- If a cylinder falls over and breaks the main valve off, the cylinder will become a missile and cause extreme damage.
- Wear a leather apron or similar protective clothing and welding gloves when using an oxyacetylene torch. T-shirts, nylon and polyester blend clothing will not provide enough protection. Ultraviolet light and sparks of hot metal will pass through them.
- Always use proper welding goggles. Do not use sunglasses because they do not filter the extreme ultraviolet light as effectively. The plastic used in sunglass lenses will not protect your eyes from sparks.
- Never point the lighted flame toward another person or any flammable material.
- Always light the oxyacetylene torch with the striker. A cigarette lighter or match would put your hand too close to the igniting tip.
- Wherever possible, use a heat shield behind the component you are heating. This will prevent nearby objects from becoming hot.
- After heating a piece of metal, label it as "HOT" with a piece of chalk so that others will not attempt to pick it up.
Part 2: Step-by-step instruction
- Light the torch and adjust neutral flame
Light the torch and adjust the gas flow so that you have a neutral flame.
- Heat for 'Removal'
Place a flywheel and ring gear assembly on a set of insulating spacers, to elevate it from the working surface. Direct the flame onto the ring gear and apply the heat until smoke starts to appear. Stop applying the heat. At this stage, the ring gear is hot enough to remove by gently tapping with a hammer and drift. DO NOT TOUCH the metal with your hands. Use welding Gloves and tools that are designed for use in a hot environment.
- Heat to 'Red Hot'
Direct the flame to the component you wish to heat. If the component is made from thin metal it will heat quicker than one that is thicker. Apply the heat evenly, until you notice the object begin to glow red. Once the glow is uniform, the metal will now be hot enough to manipulate. Once again DO NOT TOUCH the metal with your hands. Use welding gloves and tools that are designed for use in a hot environment.
- Shut down
When you have finished the job, you will need to shut down the equipment. Turn off the acetylene valve on the torch handle. This will extinguish the flame. Turn off the oxygen valve on the torch handle. Next, remove your safety goggles or mask and your welding gloves. Turn the main cylinder valve clockwise on the top of both gas cylinders. Now open the two valves on the torch handle to “bleed” the system. Turn both the oxygen and acetylene regulator handles counter-clockwise until they are loose. Close both valves on the torch handle. Put the handle and tips away, and return the gas cylinders and their hoses to their proper storage area.
