What is the minimum diameter of a trip test connection or manifold pipe required?

The minimum diameter of a trip test connection or manifold pipe is specified to ensure adequate flow and pressure when testing the sprinkler system. A 1-inch diameter is required for these connections because it provides sufficient capacity to handle the volume of water needed for effective testing. This size allows for reliable assessment of system performance, including flow rates and pressure drops, which are critical for ensuring the sprinkler system functions correctly in an emergency.

Using a pipe with a smaller diameter could restrict the flow, leading to inaccurate test results, and potentially failing to identify deficiencies in the sprinkler system. Therefore, specifying a minimum of 1 inch ensures compliance with applicable codes and standards, promoting safety and effectiveness in fire protection systems.