MCC-NH Gas Fitters Practice Exam

What type of plastic piping is accepted for use as gas pipe?

1. Polypropylene Pipe

2. Polyethylene Pipe

3. PVC Pipe

4. Vinyl Pipe

The correct answer is: Polyethylene Pipe

Polyethylene pipe is specifically accepted for use as gas pipe due to its excellent resistance to internal pressure and environmental stress cracking. Polyethylene is flexible, which allows for easier installation and adaptability in various environments. It provides a reliable barrier to gas leaks, an essential characteristic for safety in gas supply systems. In contrast, other options, such as polypropylene pipe, PVC pipe, and vinyl pipe, are not suitable for transporting gas for various reasons. Polypropylene has a lower temperature tolerance and is not typically used for gas applications. PVC, while used in many plumbing and drainage systems, is not approved for gas due to its potential to become brittle over time and its inability to accommodate the pressures and temperatures associated with gas systems. Similarly, vinyl pipe lacks the necessary durability and safety certifications for gas delivery, making polyethylene the clear choice for gas piping solutions.