What type of fluid is allowed to test connections of gas piping systems after minor repairs?

The use of a noncorrosive leak-detecting fluid is appropriate for testing connections of gas piping systems after minor repairs because these fluids are specifically designed to identify leaks without causing damage to the components of the gas system. Noncorrosive leak-detecting fluids typically contain ingredients that do not react negatively with metals, plastics, or gaskets found in gas piping systems. This minimizes the risk of introducing corrosive substances that could degrade the system over time.

Natural gas is not suitable as a testing medium because it is combustible and poses a significant safety risk if a leak were to occur during testing. Similarly, corrosive liquids would not be appropriate as they could damage the piping and connections, leading to further complications or failures in the system. Water-based solutions, while potentially safe in some contexts, may not provide the necessary surface tension or viscosity to effectively identify small leaks in gas connections. Therefore, noncorrosive leak-detecting fluid is the safest and most effective option for ensuring the integrity of gas piping systems after minor repairs.