Sprinklers and Flow

Video By Eric Goodman

Automatic sprinklers have a remarkable success record, often extinguishing a fire with just a few sprinkler heads before the arrival of the fire department. Sprinklers have a distict advantage over firefighters attacking fires with hoselines because they are already "on the scene" before fire companies even leave the firehouse.

Despite their remarkable performance, every year buildings that are considered "fully sprinklered" are destroyed by fire, often resulting in the loss of hundres of jobs and a blow to the economy of a community. Sprinklers fail to control fires due to various impairments such as a lack of maintenance, firefighters closing valves prematurely, and changes in occupancy, fire load, and storage configuration.

For example, a warehouse storing office furniture changes occupancy to a facility storing styrofoam cups and plates on 30-foot high storage racks. It is entirely possible that a fire involving the foam plastics will overwhelm the designed discharge density (gpm/square feet). Property managers and fire prevention bureau personnel must ensure that sprinkler systems are inspected and maintained in accordance with National Fire Protection Association Standard 25, Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems. Additionally, firefighters responding to a sprinklered building should give sprinkers their "best shot" at controlling a fire by ensuring that valves are opened and not prematurely closed in an effort to improve visibility for manual firefighting. Firefighters must understand that sprinklers may just barely be controlling a fire, at the limits of their capability.

In this video, water is just barely flowing from this array of sprinklers at Sprinklermatic University in Davie, Florida. This is to demonstrate what can occur when more sprinklers were activated than the system was designed to flow. Watch the impressive increase in flow when the facility's diesel fire pump is started.

Firefighters must realize that not every sprinklered building has a fire pump and fire pumps can fail to start. When firefighters respond to a fire in a sprinklered building, they can have the effect of installing a fire pump by supplying fire department connections with their apparatus, preferably from municipal water mains that are not part of the building's suppression system piping.

BILL GUSTIN is a 49-year veteran of the fire service and a captain with Miami-Dade (FL) Fire Rescue. He began his fire service career in the Chicago area and is a lead instructor in his department's Officer Development Program. He teaches tactics and company officer training programs throughout North America. He is a technical editor and an advisory board member of Fire Engineering and FDIC International.