Dry-Pipe Sprinkler System
Definition - What does Dry-Pipe Sprinkler System mean?
A dry-pipe sprinkler system is a type of fire-extinguishing sprinkler system in which the pipes are filled with pressurized air or nitrogen rather than water.
Dry-pipe sprinklers are used to offer fire protection in environments that are cold enough that the water in a wet-pipe sprinkler could potentially freeze, which would either reduce the sprinkler's effectiveness or damage it enough to make it inoperable.
Safeopedia explains Dry-Pipe Sprinkler System
In a dry-pipe sprinkler system, the pressurized air is used to hold a remote valve in a closed position. When the sprinklers are activated, the air is released from the pipes, resulting in the valve being released. This allows water to enter the sprinkler pipes and flow through the open sprinklers onto the fire.
Dry-pipe sprinkler systems are the second most common type of sprinkler system used in buildings. In jurisdictions with fire safety regulations based on the NFPA’s consensus standards, they must be used in any area with ambient temperatures that dip below 40oF/4oC. As a result, unheated workplaces such as warehouses in reasonably cold regions or refrigerated warehouses in any region must use dry-pipe systems.
The proper use of sprinklers is described by NFPA Standard 13, which mandates that water must begin deploying from a dry-pipe sprinkler system a maximum of 60 seconds after the system is activated. This time limit may be shorter for sprinklers used in certain high-hazard areas.
Dry-pipe sprinklers offer no advantages compared to wet-pipe sprinklers aside from their use in unheated buildings and refrigerated areas. Compared to wet-pipe systems, they require more maintenance to remain reliable, have stricter requirements regarding their maximum size, and face an increased risk of corrosion. According to an NFPA report, one or two sprinkler heads is sufficient to extinguish 81% of fires when a wet-pipe sprinkler is used but only 56% when a dry-pipe sprinkler is used.