What type of system contains water for immediate discharge from sprinklers opened by heat?

What type of system contains water for immediate discharge from sprinklers opened by heat?

• A. wet pipe system
• B. dry pipe system
• C. deluge system
• D. deluge with dry pipe

Answer: (A)

Water-filled pipes that discharge immediately when heat opens a sprinkler head define a wet pipe system. Because the piping contains water at all times, heat causes a sprinkler’s fusible link or bulb to release, and water flows right through that head without delay. In a dry pipe system, the pipes are charged with air or nitrogen, with water held back at a remote valve; once a head is activated, water must travel into the piping, causing a short delay. Deluge systems have all heads open and are typically filled with water, but water is released to all heads when the system is activated, not just through a head that’s been opened by heat. The combination dry pipe-deluge arrangement isn’t defined by immediate discharge from a heat-activated head.

Water-filled pipes that discharge immediately when heat opens a sprinkler head define a wet pipe system. Because the piping contains water at all times, heat causes a sprinkler’s fusible link or bulb to release, and water flows right through that head without delay.

In a dry pipe system, the pipes are charged with air or nitrogen, with water held back at a remote valve; once a head is activated, water must travel into the piping, causing a short delay. Deluge systems have all heads open and are typically filled with water, but water is released to all heads when the system is activated, not just through a head that’s been opened by heat. The combination dry pipe-deluge arrangement isn’t defined by immediate discharge from a heat-activated head.