Which type of plastic pipe cannot be used for water service?

The choice of CPVC as the type of plastic pipe that cannot be used for water service is aligned with common plumbing guidelines. CPVC, or chlorinated polyvinyl chloride, is designed primarily for hot water distribution and is commonly used in residential and commercial applications for both hot and cold water. However, it is important to note that using CPVC for underground water service is typically not recommended.

In contrast, the other types of plastic pipes mentioned can be utilized for various types of water service. PVC (polyvinyl chloride) pipes are widely used for cold water service and drainage systems. PE (polyethylene) is commonly utilized for underground water services, including potable water lines due to its flexibility and resistance to cracking. PEX (cross-linked polyethylene) is becoming increasingly popular for plumbing applications, including both hot and cold water systems, due to its ease of installation and flexibility.

The context of this question likely stems from specific plumbing codes and regulations that dictate the appropriate use of materials for different applications, helping professionals make informed decisions regarding the materials they utilize for water service.