Technical Standards and Safety Authority (TSSA) G3 Practice Exam

Is it necessary to purge each branch supply line in a pipe system?

1. No

2. Yes

3. Only where the branch supply line size is larger than NPS 2 ½

4. Only where the branch supply line will be operating at a pressure in excess of 0.5 psig (3.5 kPa)

The correct answer is: Yes

Purging each branch supply line in a piping system is necessary to ensure that there are no impurities, moisture, or residual materials that could contaminate the system or affect the quality of the gas or fluid being conveyed. This process helps to establish a clean, safe operating environment and is crucial for maintaining the integrity and efficiency of the entire system. When purging is performed, it also addresses potential hazards associated with gas build-up or contamination that could lead to system failure, malfunctions, or safety risks. Additionally, purging ensures that all air and unwanted substances are expelled from the system before it becomes operational, helping to prevent potential issues such as combustion problems or pressure fluctuations. The other choices indicate scenarios where purging might not be strictly required, but such exceptions do not encompass the broad safety and operational benefits provided by purging each branch in general. Therefore, the necessity of purging applies universally, ensuring optimal performance and safety across all lines.