Actual delivered density (ADD) test apparatus

The actual delivered density (ADD) test apparatus consists of 20 half-meter-square water measurement devices (collectors). Sixteen of the water collectors are positioned approximately 90 inches above the floor in four groups of four. A six-inches longitudinal and transverse flue space separates each group. Four additional water collectors are positioned below the upper array of 16 collectors to gather the water passing through the flue spaces. Eight groups of three heptane nozzles are arranged below the upper array and above the flue space collectors. These nozzles are capable of generating a fire plume from 0.1 to 3.5 MW. The array simulates a rack storage configuration commonly found in a warehouse. The equipment is used to characterize and evaluate the capability of storage and early-suppression fast-response (ESFR) sprinklers to penetrate the fire plume of a rack storage commodity arrangement. The apparatus can also be used by sprinkler manufacturers to develop sprinklers for various applications by comparison testing to Listed designs that have successfully passed large-scale fire testing.

Test Standards

UL 1767, the Standard for Safety of Early-Suppression Fast-Response Sprinklers

Test Equipment

• The test laboratory consists of a 30-by-30-foot room with a 21-by-21-foot movable ceiling.
• The ceiling can be raised to a height of 25 feet from the floor.
• The water supply can be adjusted to provide sprinkler pressures from 7 psi to 200 psi and can flow in excess of 700 gpm.
• The water discharged in the room is removed through a grated trench surrounding the test array.
• The rate of heat release, water flow and ceiling height can be adjusted during the test from the control room adjacent to the laboratory.
• A large window allows the technician to continuously monitor the test from the control room and make adjustments as needed.