Preventing Leaks in the Cutting Torch Hoses

Leaks in the lines between your cutting torch and the cylinders supplying its flame with oxygen and acetylene are one of the primary hazards of the oxyacetylene welding method, but can be prevented by diligence and a few simple tests. A leak can release extra oxygen – which can radically alter the properties of the air surrounding you and cause various substances, including your body, to become considerably more flammable – while leaking acetylene can lead directly to an explosion.

It is necessary to check for leaks prior to welding or cutting with your oxyacetylene torch. Checking should be carried out every time the hoses are attached, since most leaks are caused not by physical damage but by incorrect tightening of the couplings, or slight mis-threading during their application. If the hoses were left on the cylinders while they were not in use (not a recommended procedure), then the leak check should still be made before you actually use the torch. With a device that can explode fatally in the event of carelessness, it is always better to be safe than sorry.

Testing for leaks can be carried out with or without the aid of leak-detection solution. Leak-detection solution is a chemical available at welding shops which should sprayed onto the connections of the hoses – anywhere where one component has been screwed onto another, in fact. Pressurize the system, allowing gas to flow into the hoses without actually lighting the torch yet, and observe the sprayed joints closely. If there is leakage, the solution on the couplings will froth slightly as the gas escapes through it, rather like a child’s soap-bubble toy.

Alternatively, you can opt to rely on the pressure itself to inform you if there is a leak present. Pressurize the system, then turn the valves on the regulators (the spigot or tap attachment on the top of the gas cylinders) to the off position, trapping pressurized gas inside the hoses and welding torch without any more gas being able to enter them from the cylinders.

Observe the pressure reading on the regulators – those on both cylinders – for 2 to 4 minutes. If the pressure remains constant, then the couplings are all firmly seated and there are no leaks. On the other hand, if the pressure has dropped even slightly, then there is a leak, probably caused by a poorly-tightened coupling. When this is the case, you should identify the source of the leak – possibly using leak-detection solution – correct it, and then go through the entire leak detection procedure again. Your life could potentially depend on preventing the leaks, which means that failing to deal with them correctly could be an irreversible mistake.

There is also a possibility that there is actual damage to the hose, regulator, or cutting torch. In this case, simply tightening the couplings again (which must be done firmly but not so tightly that you risk distorting the threads and possibly causing a leak) will not solve the problem, and professional repair is in order as soon as possible.