Dry Alarm Valve

Overview

A Dry Alarm Valve is a key component of dry pipe fire sprinkler systems, where the sprinkler piping is filled with compressed air instead of water. These systems are specifically designed for environments where freezing temperatures could otherwise damage a wet pipe sprinkler system.

System Function (As Provided)

The primary function of both wet and dry alarm valves is to maintain the correct balance between air pressure and water pressure within an automatic fire extinguishing system. In dry pipe systems, the dry alarm valve prevents water from entering the piping until a sprinkler operates.

Dry Pipe System Configuration (As Provided)

In a dry pipe sprinkler system, the dry alarm valve is installed between the compressed air supply and the water supply. The valve ensures equilibrium between air and water pressures and prevents unintended water flow into the piping network.

Main Components (As Provided)

• Valve body
• Delay chamber (retard chamber)
• Water motor alarm gong
• Pressure switch

Operating Principle (As Provided)

Under normal conditions, compressed air pressure in the sprinkler piping holds the dry alarm valve in a closed position, preventing water from entering the system. When a sprinkler head opens due to heat from a fire, the air pressure drops. Once the air pressure falls below the designed threshold, the higher water pressure opens the valve, allowing water to flow into the piping and discharge through the activated sprinklers.

Installation Requirements (As Provided)

The dry alarm valve must be installed in a location where there is no risk of freezing, ensuring reliable operation. Installation should only be carried out by specialist engineers, as correct pressure balance and system configuration are essential for safety and performance.

Pressure Balance & Air Supply (As Provided)

The required air-to-water pressure ratio is defined by the manufacturer and can be found in the installation diagrams. A continuous and stable air supply is necessary to support the dry alarm valve and maintain the system in a ready state.

Applications (As Provided)

• Cold storage facilities
• Unheated warehouses
• Parking garages
• Industrial buildings exposed to freezing conditions

Operational Benefits (As Provided)

• Prevents water freezing within sprinkler piping
• Reliable fire protection in low-temperature environments
• Clear alarm activation via water motor gong and pressure switch
• Essential safety component for dry pipe sprinkler systems