The pre action device is the main component of the pre action automatic sprinkler fire extinguishing system, consisting of a pre action alarm valve group, a control panel, an air pressure maintenance device, and an air supply device. It is a one-way valve group device that can be opened by electric, pneumatic, mechanical, or other methods to allow water to flow into the sprinkler system in one direction and trigger an alarm. Both the control cabinet and air supply device require an external power supply of 220V. When the pre action automatic sprinkler fire extinguishing system is in standby mode, the water distribution pipeline behind the pre action alarm valve is not filled with water, but with air at a pressure of 0.03-0.05MPa to monitor the sealing of the pipeline network. The adjustment of the electric contact pressure gauge for controlling the supply device is: low 0.03MPa, high 0.05MPa. When a fire occurs, the supporting fire automatic alarm system is linked or remotely controlled, and the pre action alarm valve group is manually activated. The water distribution pipeline is filled with water, and the end electric exhaust valve is converted to a wet automatic sprinkler fire extinguishing system, while issuing an alarm signal. Wait for the fire to further develop and activate the sprinkler to extinguish it. The pre action automatic sprinkler fire extinguishing system is suitable for places that are afraid of water damage and places where the ambient temperature is below 4 ℃ or above 70 ℃.
3、 Working principle of pre action alarm valve
The rain alarm valve is the main component of the pre action alarm valve group. The rain alarm valve has a water supply chamber, a system chamber, and a control chamber. When in standby mode, the pressure water in the control chamber pushes the diaphragm to seal the valve seat, separating the water supply chamber from the system chamber, and the rain alarm valve closes. When the solenoid valve is started or manually started, the control chamber is depressurized, and the pressure water in the water supply chamber pushes the diaphragm away from the valve seat, and the alarm valve opens.
4、 Control panel
The control panel of the pre action device is equipped with power voltage (working power and backup power) display, pre action alarm valve group open and open status display, solenoid valve manual opening button, high and low pressure alarm display, system inflation status display, etc. When the air pressure in the pipeline network is normal, the signal light for normal air pressure will light up. When the air pressure in the pipeline drops below normal due to leakage, the electric contact pressure gauge will activate, the alarm will sound, the air pressure alarm signal light will turn on, and the alarm signal will be sent to the control center. When a fire occurs, the solenoid valve is activated, the pre action alarm valve group is opened, the solenoid valve working light is on, and the solenoid valve start signal is fed back to the control center.
5、 Air pressure maintenance device
The air pressure maintenance device is equipped with an air filter, pressure regulating valve, one-way valve, control air pump electric contact pressure gauge, and monitoring air pressure alarm electric contact pressure gauge. The compressed air from the air compressor is sent to the system pipeline network at the required pressure through the pressure regulating valve of the air pressure maintenance device. The one-way valve set ensures that water entering the pipeline network will not overflow into the pipeline transporting compressed air. Adjust the electric contact pressure gauge of the control air pump to a low pressure of 0.035MPa/high pressure of 0.05MPa, while adjust the value of the electric contact pressure gauge monitoring the pipeline pressure to a low pressure of 0.02MPa/high pressure of 0.06MPa.
6、 Adjustment steps for the response state of the pre action device
1. Close the butterfly valves and all ball valves above and below the pre action valve group, and cut off the power to the solenoid valve;
2. Open ball valve 4 on the left side of the pre action valve group, and then open the butterfly valve under the pre action valve group to supply water;
3. Open the ball valve 2 on the right side of the pre action valve group to exhaust, and close it after water is discharged;
4. When the pressure values of the water supply pressure gauge and the control chamber pressure gauge are equal, close ball valve 4;
5. Open ball valve 5 directly behind the pre action valve group to drain water. After draining the water, close this ball valve;
6. Open ball valve 3 and test for alarm. Then close it;
7. Open the butterfly valve and alarm ball valve 1 above the pre action valve group;
8. After the system is inflated as required, the pre action device enters the standby state.
7、 Precautions
1. The pre action device should be installed indoors with good lighting and anti freezing, and there should be sufficient space around it for installation and maintenance;
2. The pre action alarm valve must be installed vertically;
3. The pre action device must be supervised by a dedicated person;
4. Signal butterfly valves must be installed above and below the pre action alarm valve;
5. The ball valve on the pre action alarm valve must be closed when in response state;
6. When the water supply is cut off, the lower signal butterfly valve of the pre action alarm valve must be closed. When the water is supplied again, the adjustment steps of the pre action device should be followed again to adjust the response state;
7. Hydraulic alarm bell users can install it themselves according to their needs. The diameter of the water inlet of the hydraulic alarm bell is 3/4 ", and the piping needs to be tapered. The drainage outlet of the hydraulic alarm bell must face downwards;
8. The operation and maintenance of the air compressor should refer to the user manual of the air compressor. The air compressor is mainly used for supplying air to the system to prevent damage due to long-term continuous operation.
Ordering Instructions
When ordering pre action devices, please specify the product name, model, specifications, quantity, and required delivery date in the order. 2. The configuration of the pre action device includes: one set of pre action alarm valve, one set of air pressure maintenance device, one pre action control panel, one air compressor, one user manual, and one certificate of conformity. If there are any changes or additions due to design requirements, please indicate them when placing an order. If other accessories are needed, they need to be ordered separately.