(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 Sec. 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.