The planar arrangement of water mist nozzles can be rectangular or rhomboid. When arranged in a rectangular pattern, the distance between water mist nozzles should not exceed 1.4 times the radius of the water mist cone's base circle; when arranged in a rhomboid pattern, the distance between water mist nozzles should not exceed 1.7 times the radius of the water mist cone's base circle. Nozzles should preferably be evenly arranged in a rectangular, square, or rhomboid pattern at the top of the protected area, with a nozzle spacing not exceeding 3.0m and not less than 1.5m.
Specific arrangement requirements apply to different protected objects. When protecting oil-immersed power transformers, water mist nozzles should be installed at the insulator riser orifices, oil conservator, radiator, and oil sump. When protecting Class A, B, and C liquids and flammable gas storage tanks, the distance between the water mist nozzles and the outer wall of the protected tank should not exceed 0.7m. When protecting cables, the water mist should completely surround the cables. When protecting conveyor belts, the water mist should completely envelop the head, tail, and upper surface of the upward-moving conveyor belt of the fire-prone conveyor.
