Which are the four main types of water-based sprinkler system configurations commonly found in facilities?

• A. Wet-pipe, dry-pipe, deluge, and pre-action systems.
• B. Wet-pipe, dry-pipe, quench, and vented.
• C. Wet-pipe, dry-pipe, foam, and deluge.
• D. Wet-pipe, mist, deluge, and pre-action.

Answer: (A)

The main idea is recognizing the four primary water-based sprinkler system configurations used in facilities. Wet-pipe systems keep the piping filled with water, so once a sprinkler head is activated, water flows immediately to control the fire. Dry-pipe systems keep the pipes charged with air or nitrogen and hold back the water at a valve; when a head is triggered, the air releases, filling the pipes with water before it reaches the heads, which slows the initial water flow and reduces water damage risk in unheated spaces. Deluge systems have all sprinkler heads connected to a common water supply with open heads, so water is discharged from every head as soon as the system is activated, providing rapid, wide coverage—useful in high-hazard or unoccupied spaces. Pre-action systems require a two-step process to release water into the pipes (often triggered by detection or a control device), which greatly reduces the chance of accidental discharge in sensitive areas.

The other terms aren’t considered the four main configurations of water-based sprinkler systems; they describe variations or technologies that are used in special cases, but don’t represent the standard primary configurations.