G2 Gas Fitter Practice Exam

What does "purging" a pipe system involve?

1. Adding more of the same fluid to the system

2. Flushing the system with chemicals for cleaning

3. Replacing the existing fluid in the piping with a desired fluid

4. Emptying the entire system of its contents

The correct answer is: Replacing the existing fluid in the piping with a desired fluid

Purging a pipe system involves replacing the existing fluid in the piping with a desired fluid. This process is essential for ensuring that the system operates efficiently and safely, especially in gas systems where the presence of an unwanted or incompatible fluid could lead to performance issues or hazards. When purging, technicians typically remove gases or fluids that could be harmful or are no longer needed, thereby allowing the introduction of the correct fluid necessary for the system's function. This is particularly critical in applications where different types of gases or liquids could react negatively with each other or cause blockages. In contrast, adding more of the same fluid simply increases the volume without changing the type or condition of the fluid in the system. Flushing with chemicals is geared towards cleaning and may not necessarily involve replacing the fluid with a new desired fluid. Finally, emptying the entire system of its contents does not ensure the introduction of the desired fluid—it merely removes everything, which could lead to a dry system that is not ready for operation. Therefore, the process of purging is specific to replacing one fluid with another to maintain the system's intended function.