Which sprinkler system is used to protect areas subject to freezing by replacing water in piping with pressurized air or nitrogen?

Which sprinkler system is used to protect areas subject to freezing by replacing water in piping with pressurized air or nitrogen?

• A. Wet-pipe system
• B. Dry-pipe system
• C. Deluge system
• D. Foam-water system

Answer: (B)

The main concept here is protecting piping in freezing environments by keeping water out of most of the system until needed. In a dry-pipe sprinkler system, the pipes are charged with pressurized air or nitrogen, and water is held back by a dry-pipe valve located in a heated, non-freezing area. When a sprinkler head is activated, the dry-pipe valve opens and water rushes into the dry-pipe network, pushing the air out and delivering water to the heads. Because the piping remains filled with air until activation, the system is minimized for freezing damage in areas that experience freezing temperatures. The other options would either have water in the pipes all the time or use foam concentrates, which isn’t suited for protecting unheated spaces from freezing.

The main concept here is protecting piping in freezing environments by keeping water out of most of the system until needed. In a dry-pipe sprinkler system, the pipes are charged with pressurized air or nitrogen, and water is held back by a dry-pipe valve located in a heated, non-freezing area. When a sprinkler head is activated, the dry-pipe valve opens and water rushes into the dry-pipe network, pushing the air out and delivering water to the heads. Because the piping remains filled with air until activation, the system is minimized for freezing damage in areas that experience freezing temperatures. The other options would either have water in the pipes all the time or use foam concentrates, which isn’t suited for protecting unheated spaces from freezing.