The Inbal dry pipe system is a sprinkler system employing automatic sprinklers installed on a piping system containing air or nitrogen under pressure.

This dry pipe valve is used to hold back the water supply and to serve as the water / air interface. It is designed so that a moderate amount of air pressure will hold back a much greater water pressure. When a fire occurs and enough heat is generated, one or more sprinklers will operate. The system's air pressure will then escape through the open sprinkler(s) and drop to a predetermined level to allow the dry pipe valve to open. Once the dry pipe valve opens, the water supply will be admitted into the sprinkler system piping to fill it, and water will discharge from any sprinkler(s) that have operated. Dry pipe systems are used in environments that may be subject to freezing temperature.

Inbal Dry Pipe Valves are FM approved to 300 psi (21 bar) in sizes 3", 4", 6", and 8" (80, 100, 150, and 200 mm).