MCC-NH Gas Fitters Practice Exam

When testing a new branch installed on an existing system, what method is used to identify leaks?

1. Pressure testing the entire system

2. Using a combustible gas leak detector

3. Applying bubble solution to the connections

4. Using a thermal imaging camera

The correct answer is: Applying bubble solution to the connections

Applying bubble solution to the connections is an effective method for identifying leaks in a new branch installed on an existing gas system. This technique involves using a detergent or soapy solution that forms bubbles when it comes in contact with escaping gas. If there is a leak present, the gas will break through the solution, creating visible bubbles at the point of the leak, which allows for prompt detection and repair. This method is widely utilized for its simplicity and effectiveness in localized testing. Pressure testing the entire system can provide information about overall system integrity but may not pinpoint specific leaks as effectively as the bubble solution method. Using a combustible gas leak detector is also a viable option; it helps in detecting gas in the air but may not directly show the exact location of the leak as quickly as a bubble solution would. A thermal imaging camera is typically used for identifying heat loss or hotspots rather than for detecting gas leaks, making it less suitable for this specific application.