Dry pipe sprinkler system overview
Dry pipe sprinkler systems work where wet pipe systems can’t. In cold weather, wet pipes may freeze, causing damage and leaving the site without sprinkler protection. In a dry pipe system, the pipes are empty. Water is held back in a warmer area until the system is triggered. When activated, water fills the pipes and is released onto the fire. Dry pipe systems are more complex and less flexible than wet pipe systems. They are used only where cold temperatures make wet pipe systems unsuitable.
The technology
Dry pipe sprinkler systems are somewhat more complicated that wet pipe systems. They use air pumps to maintain air or nitrogen under pressure in the pipes. When a dry pipe sprinkler head is triggered, the air pressure in the pipe system drops. This change sets off a dry pipe valve. The valve opens, and the pipes fill with water. Because dry pipe systems do not fill with water until a sprinkler head has been activated, there is a delay (up to one minute) before water reaches the fire.
Like wet pipe systems, sprinkler heads are heat-activated. Each head is blocked off by a heat sensitive plug. The heads are triggered when fire melts away the plug. After the dry pipe valve has been tripper, water releases automatically from any sprinkler that reaches the melting point. Sprinkler heads not near the fire are not activated. Each head must be tripped individually.
Dry pipes sprinkler systems are more prone to corrode than wet pipe systems, so they require more maintenance and testing. They are also more expensive to design, equip, and install.
Applications
Dry pipe sprinkler systems are used in environments where freezing temperatures (below 40 degrees) are a concern. They are commonly used to provide year-round fire protection in unheated warehouses, parking garages, loading docks, and covered outdoor areas.
Call Global Fire Prevention today at (845) 781-0117 to learn how we can help protect your building.