What size of auxiliary drain is required for trapped water between 5 and 50 gallons?

The correct answer indicates that a ¾” auxiliary drain is required for trapped water volumes between 5 and 50 gallons. This size is appropriate because it allows for effective drainage of the water collected in a system's low points, avoiding issues like stagnation or water hammer that can lead to system failure or inefficiency.

In sprinkler systems, it is crucial to have properly sized drains to ensure that any trapped water can be evacuated swiftly and effectively. A ¾” drain strikes the right balance between ensuring adequate flow rate while not taking up excessive space or requiring larger support infrastructure. This allows for efficient maintenance and functionality of the fire protection system.

Sizes smaller than ¾” might not permit adequate outflow for the volume of water specified, risking potential overflows or pressure build-up. Conversely, larger sizes like 1” or 1½” might be unnecessarily large for this application, which could lead to challenges in installation, increased costs, and potential misalignment with design specifications that focus on more common, compact sizing for drains in this range.