What material is typically used for pressure testing gas piping?

Pressure testing gas piping is essential to ensure that there are no leaks and that the system can safely handle the operating pressure. The material commonly used for this purpose is nitrogen. Nitrogen is an inert gas, which means it does not react with other materials, making it ideal for pressure testing, particularly as it eliminates the risk of combustion which could occur if flammable gas were used.

Using nitrogen for pressure testing also allows for accurate readings, as it cannot dissolve in the piping materials or react with them, ensuring that any changes in pressure during the test are solely due to leaks in the system. Compared to other gases, nitrogen is widely available, cost-effective, and safe, making it the standard choice in the industry for this purpose.

Water is not typically used as it can introduce complications, such as corrosion over time or the potential for freezing in some conditions. Helium, while also inert, is more expensive and is generally used in specific applications like testing for very small leaks where higher sensitivity is required. Oxygen is highly reactive and poses significant safety risks when dealing with gas systems, hence is never used for pressure testing.