What is the maximum distance allowed from the last hanger to the end of a 1 1/4-inch line?

The maximum distance allowed from the last hanger to the end of a 1 1/4-inch line is 36 inches. This requirement is specified in order to ensure proper support and stability of the pipe. Adequate support is crucial for maintaining the integrity of the sprinkler system, as excessive distances can lead to sagging or bending of the line, which could result in improper fluid flow or even failure of the system.

Correct hanger spacing helps to distribute the weight of the pipes and any water they contain, reducing stress points along the system. For 1 1/4-inch lines, the industry standard limits the distance to 36 inches to provide sufficient support, balancing functionality and structural integrity.

While other distances may be applicable to different pipe sizes or types of installations, the specific limitation of 36 inches for a 1 1/4-inch line conforms to established fire protection engineering practices aimed at optimizing performance and safety in sprinkler systems.