What common household item is used to test for leaks on LP gas and oxy-acetylene valves?

The use of soapy water to test for leaks is a widely accepted practice in identifying gas leaks. When soapy water is applied to the area around valves or connections, any escaping gas will create bubbles. This is due to the surface tension of the soap, which allows the bubbles to form and grow larger if gas is indeed escaping. This method is not only effective but also safe, as it does not involve any flammable or hazardous substances.

In contrast, options like alcohol, oil, and vinegar are not suitable for leak detection as they do not have the same bubble-forming properties or may pose safety risks. Alcohol can evaporate too quickly to be effective, oil might leave a residue that complicates detection, and vinegar does not produce bubbles in the same way that soapy water does. Therefore, using soapy water is the recommended technique for quickly and accurately testing for leaks in LP gas and oxy-acetylene systems.