Nozzles that produce a hollow cone spray pattern include:

• A. Whirl chamber
• B. Regular flat fan
• C. Raindrop
• D. CDA

Answer: (C)

Hollow cone patterns spray droplets in a ring, leaving the center of the spray invisible, so the coverage forms a circle around the nozzle rather than a filled disk. The raindrop nozzle is the one most commonly described as producing this hollow-cone, ring-like spray, which mimics a rainfall arc around the target and provides even edge coverage. The regular flat fan creates a flat sheet of spray, not a ring, so it doesn’t form a hollow cone. Whirl chamber describes a mechanism to generate spray and can produce cone shapes, but it’s not the pattern name typically used for hollow-cone nozzles. CDA isn’t a standard pattern type for hollow cones.