What is the maximum unsupported length of any arm over in a system under 100 psi?

In a sprinkler fitting system, the maximum unsupported length of any arm-over is typically defined to ensure proper support and functionality. For systems operating under 100 psi, the accepted standard for the maximum unsupported length is 24 inches. This guideline is established to prevent stress on the sprinkler piping and to ensure that the system operates effectively without risking damage or failure due to unsupported spans.

When arm-overs exceed this length, they may sag or bend under their own weight or pressure, which could lead to leaks, disconnections, or complete system failure. Maintaining the arm-over within the specified limit helps ensure that the system remains reliable, even under normal operating conditions.

Understanding these specifications is crucial for a sprinkler fitter, as adhering to them can significantly impact the safety and reliability of fire suppression systems.