Important: There are strict controls on the use of acetylene on company property, acetylene should not be used if it is possible to use another gas in its place.
Where the use of acetylene is necessary then only the minimum quantity will be allowed on site and the cylinders must be attended at all times (including break times). Should the fire alarm in the building sound then cylinder’s must be isolated (and where possible) removed from the building during the evacuation process. All gas cylinders must be removed from site every night.
Note: This checklist must be used in conjunction with the hot work permit when Oxy/Acetylene cylinders are used on site.
Compressed gas cylinders (oxygen acetylene tank and others)
Before use, have all cylinders been handled properly. Are there any physical signs of damage? Check valve assembly on each cylinder?
Inspect the chains or other device used to secure the acetylene oxygen tanks.
Be sure that each regulator is correct for the cylinder it is to be attached to. Be sure that the regulator is designed for the pressure of the cylinder. Blow out the oxygen valve assembly before attaching the oxygen regulator, to eliminate the potential for a dust explosion. Inspect the regulator and cylinder valve for presence of any oils or grease. If present, DO NOT USE. Make sure the adjusting screw has not been damaged. Check the pressure relief port.
Cutting Torch or oxy acetylene torch
Inspect the torch. Are inlet connections unsatisfactory for threading a tight connection? Is there obvious physical damage on the torch? If using a combination torch, are the O-rings at the base of the cutting attachment in place and free of cracks? Is there any evidence of soot buildup on the torch body? Are the threads satisfactory on the head of the torch, to correctly tighten in the tip? If any of these conditions are present, DO NOT USE THE TORCH.
Safety devices normally consist of check valves and flashback arrestors. These devices will be placed at the outlet of the regulator or the inlet of the torch, or both.
note:flashback arrestors at both places could restrict the flow and starve the tip when using a rosebud tip.
Check valves may be used, flashback arrestors, or both. these days check valves are usually made right into flashback arrestors.
By definition, a check valve stops the reverse flow of gas. This prevents mixed gas in the system. A flashback arrestor stops flame.
Safety devices should be replaced periodically. A check valve contains a rubber diaphram that will stop the reverse flow of gas and operates at 2 psi. If a flashback has occurred, the check valve will be damaged, but will show no evidence of this. To check, remove the check valve and apply clean, dry, oil-free air pressure, in a reverse direction, of 2 psi. If air moves through the device, IT IS NOT WORKING, and should be removed from the system, and replaced.
A flashback arrestor contains a stainless steel screen. This screen will snuff out a fire, but will allow gases to flow through. There is a restrictive property to flashback arrestors, and regulator pressures need to be set to compensate for this. Refer to the manufacturer for the amount of compensation. Flashback arrestors, such as models available from Smith Equipment, may also contain a check valve, as in the case of the Smith Equipment device. If the flashback arrestor is torch mounted, there is potential for foreign material to enter the system and plug the device. This will further restrict gas flow and starve the tip. Like check valves, flashback arrestors need to be checked periodically. In similar fashion, remove the device, applying clean, dry, oil-free air pressure of at least 2 psi, in reverse flow through the device. If air goes through, IT IS NOT WORKING, and should be removed, and replaced.