Final answer:
The support interval for PVC horizontal piping depends on its diameter, with common standards specifying a 4-foot interval for pipes less than or equal to 4 inches in diameter. Nevertheless, always refer to the manufacturer's recommendations and local codes.
Step-by-step explanation:
The question refers to the required intervals for supporting PVC horizontal piping which is a topic related to plumbing and mechanical engineering within construction practices.
The support frequency for PVC piping can vary based on the diameter of the pipe and the specifications provided by the manufacturer and code authorities.
However, a common standard is that for pipes less than or equal to 4 inches in diameter, support should be provided every 4 feet. For larger diameter pipes, the interval of support increases correspondingly.
It is important to follow the specific code and manufacturer's recommendations as they can differ based on the application and local regulations. In addition to the spacing, the type of support and method of installation are critical factors to consider to ensure the durability and proper functioning of the PVC piping system.