In a Dry Pipe Sprinkler System, what keeps the dry pipe valve closed?

In a Dry Pipe Sprinkler System, the dry pipe valve remains closed due to air pressure maintained in the system's piping. This system is specifically designed to prevent water from entering the pipes until a fire is detected. When the fire occurs and the sprinkler heads activate, the air pressure inside the pipes drops, leading to the opening of the dry pipe valve. This allows water to flow into the system and reach the activated sprinkler heads, effectively controlling or extinguishing the fire.

The air pressure within the system is critical as it acts as a barrier, ensuring that no water can leak into the pipes and cause damage or freezing, which is especially important in environments where temperatures can drop significantly. Therefore, maintaining proper air pressure is essential for the functionality of a dry pipe sprinkler system.