What is a FlashbackAnd Why is itThreatening?
When a backfire occurs in a mixing chamber, the flame burning in the torch head may ignite gases in the hoses, resulting in a flashback unless the oxygen valve is shut off During a flashback, an explosion spreads via torch, hoses, regulators, and into the cylinders. All probable results include a burst hose and a violent explosion of the regulator and cylinders. In oxyfuel cutting or welding, a flashback occurs when fuel gas ignites or burns back behind your torch tip Low oxygen pressure from the cylinder (empty bottle) or a fault with your tip can cause this (dirty or damaged) It could pass through your hoses, but most torches contain a flashback arrestor to prevent this It's commonly referred to as a burn back This could mean harm to anyone around the vicinity where the welding process is being carried out.
An explosion spreads through the torch, hoses, regulators, and into the cylinders during a flashback. A bursting hose to a powerful explosion of the regulator and cylinders could result. You can help prevent flashbacks, fires, and explosions by doing the following: When working with acetylene, keep the pressure below 15 pounds.
Flashback and backfire have a lot in common. If a backfire happens, which is normally caused by holding the cutting torch too close to your work, the same thing can happen with high oxygen pressure and low fuel gas pressure. This deprives the cutting flame of gas, resulting in the flame being sucked into the torch head. When this happens, you will usually hear a popping sound that transforms into a whistling sound
For extra safety during welding processes, flashback arrestor testing is required Flashback arrestor testing is the process where flashback arrestors are checked for any malfunctions that can lead to accidents. This process should be done once every six months or twelve months at most
To prevent flashbacks from happening, one professional person should be in charge of checking the torch How can you know if your torch has flashback arrestors and check valves? Looking at the torch, you’ll notice a little cylindrical valve on each inlet, with the hoses, screwed onto this valve rather than linked directly to the torch The majority of these valves are combination flashback and check valves, as indicated on the valve body Combination valves are frequently fitted on regulator outlets.
Because the flashback is made up of a pressure front, a flame front, and a gas back feeding, the flashback arrestor must be built properly If there is a sudden pressure change of roughly 1 2 bar, the pressure-sensitive shut-off valve will be triggered This will also activate the non-return valve, cutting off additional gas flow from the cylinders. By depressing the signal lever, the flashback arrestor can be re-opened This should not be done until the cause of the flashback has been determined. Before welding, inspect the quality of the equipment to ensure that check valves and flashback arrestors are properly installed This precaution could save your life if a cylinder explodes and can cause life-threatening accidents Prevention is better than cure as they say. For many years, oxyacetylene safety equipment torches have been used to cut, weld, braze, and heat metals Although the equipment utilized today is safe, hundreds of employees are maimed and killed each year as a result of inappropriate use. Fires and violent explosions can be avoided with knowledge and safeguards. Life has a lot of unexpected threatening events that could lead to accidents or maybe worse These life hazards should be taken into account and all must be aware of the things that they could bring to them. Having said this, safety should be the number one priority when it comes to any workplace Regardless of the professionality of the person working on site, the company should always provide them with well-maintained equipment, a correct and complete set of personal protective equipment, a first aid kit, and all the things necessary for unwanted circumstances You must also be aware of the things to do when a flashback occurs
If in any case, a flashback does occur, one should keep the following in their mind
- If it is safe to do so, immediately close the cylinder valves for acetylene and oxygen.
- Examine the condition of the cutting nozzle and the welding neck Maintain the condition of these things. Cutting nozzles and welding necks that are not properly maintained generate turbulent gas flow, which disrupts the gas mix Exit velocity, which raises the risk of inspecting nozzles and the welding neck on a frequent basis. Check that they are not obstructed by dirt or splatter. Repair or replace damaged nozzles.
- Check that the welding shank is equipped with non-return valves and that the regulators have flashback arrestors as well.