How to Use Oxy Fuel – Oxygen Acetylene – Cutting Torch Equipment Safely
An oxygen acetylene torch flame is around 6000 degrees F. Considering steel melts at around 2800F that is pretty freakin hot!
You can make a lot of things happen with an oxygen acetylene torch kit. You can braze air conditioning line sets, solder copper water pipe, silver braze stainless steel, weld 4130 chromoly tubing, and even heat and bend metal thicker than 1 inch. But oxy-fuel torches can be extremely dangerous if not used properly. OSHA even requires employers to ensure workers that use oxyfuel equipment to be properly trained and qualified for oxy-fuel welding, cutting, heating, and brazing. (see 29 CFR 1910.252)
From my 30 plus years in the welding field, I am constantly surprised by the lack of training in the safe operation of oxyfuel equipment .. Even seasoned welders are often deficient in use of oxygen acetylene torches unless they have received hands-on training where demonstration of proficiency was required
Safe operation of oxygen acetylene equipment requires training, willingness to follow basic safety guidelines, and understanding some basic safety principles:
o Oxygen cylinders are pressurized to over 2500 psi and can become a projectile if knocked over. Always, always, always keep the cap screwed on when the cylinder is not secured.
o Acetylene cylinders are filled with acetylene gas compressed into a porous substance arranged with liquid acetone. They should remain upright to prevent liquid acetone from damaging the regulators and restricting gas flow. If you have to lay them down to haul them, let them stand right for a while before using.
o Never transport or store cylinders in an enclosed space (i, e, trunk of car, or truck tool box) Welding supply stores often display pictures of cars destroyed by the explosion of oxygen and acetylene cylinders hauled in the trunk of a car. They even make you sign a waiver if you want to haul cylinders yourself.
o Never use damaged equipment.
o Always open oxygen cylinders very slowly. Opening them quickly is very dangerous and can cause the regulator to explode. Yes I said explode. (if you do not believe me, just Google "regulator burnout")
o Use check valves or combination check valve / flashback arrestors to prevent reverse flow of gases and to prevent mixing of gases.
o Never use oil on any part of the equipment. Oil in the presence of pure oxygen can ignite easily
o Always bleed down the gases and back out the regulator screws when finished using the torch
There are several different manufacturers of oxyfuel equipment: Victor, Smith, and Harris are 3 of the main brands and each designs their equipment differently with certain features in mind. So the operation of each manufacturer's torches is different. Always follow the manufacturer's instructions.
The first thing to do when preparing to operate a oxyfuel torch is to inspect the equipment. Make sure the cylinders are fastened securely to prevent them from falling over .. Next, inspect the hoses to make sure they are not cracked or dry rotted. Feel the brass connectors to make sure they are all tight and ensure the cylinders valves are closed with the regulators reading zero.
If the regulators are not reading zero, one of two things is wrong: The gauge or gauges have been damaged or the previous user failed to bleed the pressure from the line. To release the pressure, open the appropriate valve on the torch and turn the regulator screw clockwise until the needle moves to zero. If the needle does not go to zero, the gauge is damaged and must not be used.
If the gauges are determined to be operating properly the next thing to do is make sure the regulator screws are backed out where you can not feel spring pressure on them.
Here is a simple ABC, 123 checklist to use for setup and shutdown of oxy-fuel equipment.
o Wear proper Personal protective equipment ie shade 3 to 5 ANSI eyewear, gloves etc.
o Inspect the equipment for: Overall condition of hoses, zeroed gauges, check valves, torch, chains on bottles
o If gauges are not reading zero, purge lines to let gauges zero out
o If gauges are damaged replace them
o Open oxygen cylinder valves very slowly. (This is the most important step on this page)
o Select proper tip according to manufacturers guidelines
o Use manufacturers tip chart to determine pressure settings
o Set gauges
o Purge lines individually
o open acetylene torch valve to t turn and Light torch
o Increase acetylene flame high enough to where soot disappears.
o Add oxygen to flame until blue cones define creating a neutral flame.
o Perform work
o Extinguishing flame by turning off gas valves on torch (manufacturers differ on whether to turn off acetylene or oxygen first.)
o Turn off cylinders
o Purge lines
o Once gauges are zeroed, back out regulator screws
o Return torch to storage place
o Secure oxy-fuel equipment for next user