Which system uses air pressure to contain water until release?

Which system uses air pressure to contain water until release?

• A. Dry Pipe Sprinkler System
• B. Preaction Sprinkler System
• C. Residential Sprinkler
• D. Alarm Device

Answer: (A)

The system being tested uses air pressure to hold back water in the piping until a sprinkler head is released. In a dry pipe arrangement, the piping that runs through the building is kept dry and charged with compressed air (or nitrogen). A dry pipe valve at the water supply keeps water from entering the dry pipes. When a sprinkler head is activated, the air pressure drops as water starts to move into the line, the valve opens, and water rushes into the piping to the sprinklers. This setup is especially useful in unheated or cold spaces because the pipes aren’t filled with water until needed, reducing the risk of freezing and allowing a brief delay before water discharge to the heads. The other options involve systems where water is held back by mechanisms other than air pressure in the dry pipes, or refer to types of systems that are typically water-filled from the start or are not sprinkler systems at all.

The system being tested uses air pressure to hold back water in the piping until a sprinkler head is released. In a dry pipe arrangement, the piping that runs through the building is kept dry and charged with compressed air (or nitrogen). A dry pipe valve at the water supply keeps water from entering the dry pipes. When a sprinkler head is activated, the air pressure drops as water starts to move into the line, the valve opens, and water rushes into the piping to the sprinklers. This setup is especially useful in unheated or cold spaces because the pipes aren’t filled with water until needed, reducing the risk of freezing and allowing a brief delay before water discharge to the heads. The other options involve systems where water is held back by mechanisms other than air pressure in the dry pipes, or refer to types of systems that are typically water-filled from the start or are not sprinkler systems at all.