Which water test data must be included on installation tags to reflect the hydraulically designed system?

• A. Static and residual pressure with the measured gallons per minute flowing of the water supply flow test used to hydraulically design the system
• B. Static and flowing pressure of the main drain test taken at the riser or lead-in
• C. Static and residual pressure with the measured gallons per minute flowing of the water supply flow test used to hydraulically design the system
• D. Water test date

Answer: (C)

When a sprinkler system is hydraulically designed, the installation tag should show the water supply test data that was actually used to size and calculate the system. That means the static pressure (pressure with no flow), the residual pressure (pressure while water is flowing), and the measured gallons per minute flowing from the water supply flow test that was used in the design. Including these three values on the tag ties the hydraulic design to the real supply characteristics, so inspectors and future maintenance personnel can verify the system was designed for the actual conditions observed.

Simply recording the date of the water test or the main drain test data doesn’t convey the flow and pressure conditions that the design calculations were based on, so those alone don’t reflect the hydraulically designed system. The key is documenting the specific flow test data that informed the hydraulic design.