🔍 Key Concepts

• High velocity fog nozzle vs. low velocity applicator – how each produces droplets/spray • How water streams are mechanically broken up into fog patterns • What factors (pressure, pump capacity, fire type) actually change the pattern shape vs. just the amount of water

💭 Think About

• Think about what physically creates a fine fog vs. a coarse spray – what is happening to the water as it leaves the nozzle or applicator? • If you kept the same pressure but changed the way the water exits, would the spray pattern change? What if you changed pressure but kept the outlet design the same? • Which option explains the visible shape and texture of the spray, not just how much water is delivered or why you are using it?

✅ Before You Answer

• Focus on what directly affects the droplet size and dispersion pattern at the nozzle tip. • Ask yourself: which choices describe operating conditions (how much, why) versus design features (how it’s formed)? • Eliminate any option that only changes volume/force of water but doesn’t necessarily change the basic spray pattern mechanism.