Is a torch different to a blowpipe?
No.
Torches are sometimes referred to as blowpipes, lamps, blowtorches, guns, shanks, burners and handles.
Do all torches work in the same way?
No.
A number of gas mixing systems can be employed either in the shank, between the shank and the torch nozzle (known as injector torches) or in the nozzle (known as nozzle mix systems), and these may call for different working procedures.
Due to the wide range of equipment available on the market, it is imperative that operators refer to the supplier’s operating instructions in respect of nozzle selection, pressure settings, lighting and extinguishing procedures.
Which is the most common type of cutting torch used in the UK?
The most common type of torch used in the UK is the nozzle mix system. Where the pre-heat fuel gas and oxygen are mixed within the nozzle.
It’s worth remembering that the greater the quantity of mixed gas in the system, the greater the force of the explosion if they are ignited.
By not mixing the gases until they reach the nozzle, and even then, by feeding them through a number of very small channels within the nozzle, the amount of mixed gas in the system is minute.
Lighting a nozzle mix torch is both deemed to be easier and safer than lighting an injector torch, as the operator is only required to light a flow of fuel gas, as oxygen is available from the atmosphere.
With injector torches, which rely on the flow of the oxygen to draw the fuel gas through the system, it is necessary to ignite mixed gases.
Can I use the same size of nozzle to cut a wide range of steel thicknesses?
No.
BCGA CP7 states:
‘It is essential to select the correct nozzle.
Nozzles are specified to the type of fuel gas being used, are sized to the material, its thickness and its application.’
Always use cutting nozzles that are compatible with your particular torch in order to ensure there is a gas-tight seal in the torch.
How do I know what size of nozzle to fit for my particular application?
The gas companies, as well as nozzle manufacturers and suppliers, issue a range of nozzle data charts that operators can refer to.
These charts detail what size of nozzle is required to cut or gouge what thickness of plate, as well as the oxygen and fuel gas pressures that need to be set on the respective regulators.
Do I need to regularly inspect my torch?
Yes.
Torches and nozzles should be visually inspected each time prior to use.
Damaged, defective or contaminated units must not be used and should be replaced immediately.
They should also be inspected at least annually, and written records should be kept.
If my nozzle is blocked by some molten metal or slag, can I use a nail to remove it?
No.
If some of the outlet holes on your nozzle are blocked, only use a specific nozzle cleaning kit to unblock it.
These kits are available from gas suppliers and welding distributors.
