Which type of suppression system is designed to release in a sequence and is often integrated with the fire alarm system?

• A. Automatic sprinkler systems
• B. Dry chemical suppression systems
• C. Preaction suppression systems
• D. Kitchen hoods

Answer: (C)

Preaction suppression systems are built to release water in steps, not all at once. The piping is kept dry or pressurized with air until a triggering event occurs, such as a detector sensing heat or smoke and, in many designs, a manual release. When the triggering signal from the fire alarm system is received, a valve opens and water is allowed into the piping, but actual discharge from the sprinkler heads happens only after a subsequent event (like heat at a sprinkler head) or another interlock is satisfied. This sequencing reduces the chance of a full water discharge from a single false alarm and ensures the fire alarm system coordinates plus confirms the response before water is released. In environments where premature water release would cause substantial damage, this integrated, staged approach is especially valuable.

Automatic sprinkler systems release water immediately in response to heat or smoke without a preceding alarm-triggered sequence, making them unsuitable for the “released in a sequence” idea. Dry chemical systems use powder and are not defined by a staged water release coordinated with the building’s fire alarm. Kitchen hood suppression is a different, area-specific system designed for cooking fires and isn’t described by a sequence tied to the fire alarm system.