G2 Gas Fitter Practice Exam

How should underground piping be tested for leaks?

1. Visually

2. Hydrostatically

3. With soapy water

4. By pressure testing

The correct answer is: Hydrostatically

Testing underground piping for leaks is critical to ensure safety and integrity, as any leaks could lead to hazardous conditions. The correct method for leak testing underground piping is through hydrostatic testing. This involves filling the pipe with a liquid, typically water, and then pressurizing it to verify that it can maintain pressure without any drops, indicating the presence of leaks. Hydrostatic testing is particularly effective for underground piping because it allows for an accurate assessment of the system's integrity in a controlled manner. Unlike visual inspections, which are not practical for pipes buried beneath the surface, hydrostatic testing provides concrete data on whether a leak is present. This method is widely accepted in the industry for ensuring that pipelines comply with safety standards before being put into service. Other methods listed, such as using soapy water, can be practical for small or above-ground gas piping systems. However, they are not suitable for assessing underground piping due to limited accessibility and visibility. Pressure testing is a broader term that can encompass various methods, but hydrostatic testing is specifically focused on liquids, making it the standard approach for underground installations.