75% of fire systems are what type?

• A. Wet
• B. Dry
• C. Deluge
• D. Foam

Answer: (A)

Wet pipe systems keep water-filled piping, so when a sprinkler head is activated, water is released immediately. That quick, straightforward response, along with lower maintenance and installation costs, makes them the most common choice for automatic fire sprinkler installations. Because of these advantages, they make up the largest share of systems in use—about 75% in many datasets. Other types exist for specific situations: dry pipe systems use pressurized air to hold water back in the lines to avoid freezing, delaying water release; deluge systems have all sprinkler heads open and deliver water through every head once the system is activated; foam systems are specialized for high-hazard environments like aircraft hangars or chemical plants.