Red Seal Sprinkler Fitter Practice Exam

What does the term "dry pipe system" indicate?

1. System filled with air until activated

2. System only for outdoor usage

3. System that releases foam

4. System always filled with water

The correct answer is: System filled with air until activated

The term "dry pipe system" refers to a type of fire sprinkler system that is filled with pressurized air or nitrogen until a fire triggers the system. When a fire occurs and the heat activates the sprinkler heads, the air pressure drops, allowing the water stored in the remote water supply to enter the pipes and discharge through the activated sprinkler heads. This configuration is particularly advantageous in environments where freezing temperatures could cause water to freeze within the pipes, such as unheated warehouses or outdoor areas. This understanding of dry pipe systems emphasizes their design intended to prevent water from sitting in pipes where freezing could occur, while also highlighting the role of air pressure in controlling the release of water during a fire incident. The other answer choices do not accurately reflect the function or characteristics of a dry pipe system; for example, a dry pipe system is not limited to outdoor use, does not primarily release foam, and is specifically designed to avoid being filled with water until needed.