What is the maximum distance allowed from the end of a regular branch line to the last hanger for a pipe larger than 1"?

The maximum distance allowed from the end of a regular branch line to the last hanger for a pipe larger than 1" is established to ensure proper support and prevent sagging or misalignment of the piping system. In this case, the correct answer is 48 inches.

This measurement is crucial for maintaining the integrity of the system, especially as the diameter of the pipe increases. Larger pipes can carry heavier loads, and if the spacing of the hangers is too great, it can lead to undue stress on the joints and connections, potentially causing leaks or failures.

The guidelines for hanger spacing also consider factors like the weight of the pipe and the nature of the fluid it carries, thus the 48-inch limit provides a balance between adequate support and practical installation procedures. Adhering to this standard fosters a safe and reliable sprinkler system installation.