Acetylene welding flashback preventer (also commonly referred to as “flashback preventer” or “flashback prevention device”) is a crucial safety equipment.
core function
Its core function is only one: to prevent flame backfire from entering acetylene cylinders or pipeline systems, thereby avoiding severe explosion accidents.
1. What is “tempering”?
In gas welding (especially oxygen acetylene welding), tempering refers to the combustion flame no longer stabilizing outside the nozzle of the welding torch (welding gun), but burning in the opposite direction along the acetylene gas pipeline. The flame will burn back to the pressure regulator through the hose and eventually enter the interior of the acetylene cylinder.
Reason: Usually caused by nozzle blockage, overheating, improper gas pressure, or improper torch operation.
Consequence: The interior of acetylene cylinders is high-pressure and flammable gas. Once flames enter, they can cause combustion inside the cylinder, leading to a sharp increase in pressure and ultimately causing the cylinder to explode, resulting in catastrophic
2.How does the tempering preventer work?
The flashback preventer physically blocks the passage of flames. There are mainly two types:
a) Dry tempering preventer (currently the most commonly used)
This type of protector has a precise porous ceramic fire suppression element inside.
Principle: This porous structure is like a “maze” that only allows gas molecules to pass smoothly, but can greatly absorb and disperse the heat of the flame. When tempering occurs, when the flame front reaches this component, its heat is quickly absorbed by the huge ceramic surface area, causing the flame temperature to drop below the ignition point of the gas in an instant, thereby “extinguishing” the flame.
Advantages: No need to add water, unaffected by cold weather, easy maintenance, high reliability.
b) Water sealed tempering preventer (older and less commonly used for welding torches nowadays)
This type of protector is equipped with a certain height of water inside.
Principle: Gas enters the water from one pipe, bubbles up, and is discharged from another pipe. During normal operation, gas can break through the water seal and pass through. Once backfire occurs, when the flame burns back, it will instantly generate high pressure inside the preventer, pressing down the water surface and exposing the mouth of the inlet pipe to the water surface. At the same time, the exhaust gas generated by the flame combustion will be discharged from the safety port, thereby cutting off the path for the flame to enter the gas source.
Disadvantages: Regular check of water level is required, as it may freeze and fail in cold environments, resulting in a large volume.
3. Where should the tempering preventer be installed?
In order to achieve the best protection effect, the tempering preventer must be installed as close as possible to the gas source, that is:
Acetylene cylinder: installed at the outlet end of the acetylene pressure reducer.
Pipeline system: installed at the outlet end of the workshop pipeline, and then connected to a hose.
Important reminder: Some welding torch handles also come with small flashback arresters, but this cannot replace the main flashback arrestor at the gas cylinder. The combination of the two can provide dual protection.
Summary
The function of acetylene welding tempering preventer can be summarized as follows:
Intrinsic safety: It is the last and most critical line of defense against explosions caused by backfire.
Flame blocking and extinguishing: By using physical methods such as porous ceramics or water seals to absorb flame heat and block the path of flame propagation.
Protection equipment: Protect expensive pressure reducers, pipelines, and gas cylinders from damage.
Ensuring personal safety: The ultimate goal is to protect the lives and property of operators and those around them.
Therefore, qualified and regularly inspected tempering arresters must be installed during any acetylene gas welding or gas cutting operations. Without it, homework is extremely dangerous