0 items in your basket
Total £ 0.00 EX VAT
MIG Gloves
TIG Gloves
Baseball Caps
Armguards
TIG Heat Blockers
Shop 55,000 Products
SERVICEDEPT.
RAPID BLOG
FEEDBACK
HIRE
Answers to common questions about the nozzles, mixers, heating heads and cutting attachments used with a modular oxy-acetylene torch.
A non-return (check) valve fitted on the torch stops gas back-feeding into the hoses, but the HSE notes it will not stop a flashback once one has occurred. A flashback arrestor is a different device that stops a flame travelling back towards the cylinder.HSE guidance is to fit arrestors on the regulators of both the acetylene and oxygen cylinders and, for long hoses, on the torch end as well. Inspect these devices regularly and replace damaged ones. They are not a substitute for safe working practice, so keep to the manufacturer's replacement and testing advice.
Before lighting, purge the hoses one at a time by opening the gas supply to each hose for a few seconds, then close the torch valve. This flushes out any flammable mixture of gases in the hose. Work in a well-ventilated area and light the gas with a spark igniter, not a butane lighter or a match held close to your hand.Use the correct gas pressures and nozzle size for the job. The order in which to close the torch valves at shut-down differs between published instructions, so follow the sequence in your torch manufacturer's manual. Only use the equipment if you have been trained.
The HSE says poorly maintained nozzles cause turbulent gas flow, which increases the risk of flashback. Inspect nozzles regularly, make sure they are not blocked by dirt or spatter, and replace damaged ones. Holding the nozzle too close to the workpiece can overheat it and cause a flashback.A flashback can also happen if a flammable mixture of fuel gas and oxygen is left in the hoses when the torch is lit, which is why purging matters. Tips and mixers that are loose or not properly seated are another common problem, so tighten them by hand or as the maker instructs.
An acetylene cylinder contains a porous mass soaked in acetone, so it is built differently from most gas cylinders. HSE guidance says not to drop or jar it and not to roll it across the floor. Keep it upright, and if it has been laid down and returned to upright, leave it for an hour to settle before use.Check the identification and look for damage before use, and turn off all valves after use. In the UK, acetylene cylinders are normally painted maroon, but the label is what identifies the gas. If a cylinder looks damaged, the label is unclear, or it has been involved in a fire or flashback, do not use it and speak to your gas supplier.
