(a) The discharge density of each water spray system must be at least:

(1) 10000 cm 3/m 2/min. (0.25 gpm/ft. 2) over each horizontal surface; and

(2) 4000 cm 3/m 2/min. (0.10 gpm/ft. 2) against vertical surface, including the water rundown.

(b) The water spray protection under § 154.1110 (d) and (e) must cover an area in a horizontal plane extending at least 0.5 m (19 in.) in each direction from the pipes, fittings, and valves, or the area of the drip tray, whichever is greater.