How do you prevent a gas welding backfire?To reduce backfires and flashbacks, use flashback arrestors and purge hose lines before lighting the oxy-fuel gas torch. Purging flushes out any combustible oxygen-fuel gas or air-fuel gas mixtures in the hoses.
What causes backfire during oxy-acetylene gas welding?The regulator pressures and/or gas flows are incorrect. The nozzle is blocked. The nozzle has been held too close to the work. The nozzle has become overheated.
What causes the pop sound during gas welding work?A backfire (a single cracking or 'popping' sound) is when the flame has ignited the gases inside the nozzle and extinguished itself. This may happen when the torch is held too near the workpiece. A flashback (a shrill hissing sound) when the flame is burning inside the torch, is more severe.
What is backfire of acetylene?In a sustained backfire the flame burns, back into the torch handles mixing point (where oxygen and acetylene is mixed). It is characterised by an initial bang (backfire) followed by a whistling sound. If it is not quickly interrupted, the torch will melt and escaping combustion products can cause injuries.
GCEacademy (6) - FLASHBACK (Backfire, Sustained backfire, Flashback)
What is the common cause of backfire?If too much fuel is added to the engine, it may not all burn up before the exhaust valves open -- letting unburned gasoline into the red-hot exhaust headers, where it can combust and lead to a backfire. Too much fuel could be getting into your engine due to damaged and leaking fuel injectors or bad engine sensors.
Which of the following is a cause of a backfire?Common causes of backfire are running rich (too much fuel going into cylinders) or faulty ignition, possibly a fouled (dirty) spark plug, coil, or plug wire. Pop-backs are usually caused by problems with timing.
What should oxygen and acetylene regulators be set at?Recommended oxy/acetylene cutting tip pressures vary with size. If you have no manufacturer setting- information, and are cutting less than 1 ½” thick steel, set the acetylene regulator for 10 psig, and the oxygen regulator for 40 psig.
What pressure should I set oxy acetylene for cutting?Adjust the screws on the regulators so the gauge reads the proper psi. You will want between 40 and 60 psi for the oxygen tank and 10 psi for the acetylene tank.
What gas makes a popping sound?Hydrogen gas makes a small pop explosive sound when burnt.
Why does oxyacetylene torch pop?Another problem could be that, while lighting the torch, the viewer is opening the acetylene valve just slightly, then turning on the oxygen, which will cause it to pop every time. If you open up the acetylene more fully, then turn on the oxygen, no problem. Turn your oxygen off, then turn your acetylene off – no pop.
What happens when acetylene gas is too much during welding?A violent, explosive decomposition reaction can occur. pressure at or above 15 psig with red marking on the gauge. There are a number of incidents each year where a flashback into an acetylene cylinder triggers decomposition, leaving the cylinder in a dangerous, unstable condition. gas from backfeeding into the hoses.
What is the immediate action that should be done if an oxy acetylene backfire occurs?In the case of a backfire, the first priority should be to close the oxygen valve and then immediately close the acetylene valve. No operation is to be performed until the cause of the backfire is rectified.
What fixes backfire?Possible Fixes for Backfiring:
Lower engine speed slowly. Follow small engine fuel recommendations and/or switch to brands with low or no alcohol. Adjust carburetor for optimum performance. Inquire with equipment manufacturer about increasing air volume to decrease engine temperature.
How do you control backfire?
How To Prevent Your Car From Backfiring
- Change oxygen sensors. ...
- Stop air leaks. ...
- Renew that spark. ...
- Check engine belts. ...
- Keep a healthy exhaust.