Dry system is suitable for buildings and places where the ambient temperature is lower than 4℃ and higher than 70℃, such as underground garages, cold storage and other places without heating. Dry system is similar to wet system, but the structure and action principle of control signal valve are different. The main control signal valve is arranged between the water distribution pipe network and the water supply pipe to separate them, and the water distribution pipe network is usually filled with pressurized gas for system startup.
In case of fire, the nozzle ejects gas first, which reduces the pressure in the pipe network. The pressure water in the water supply pipe opens the control signal valve to enter the water distribution network, and then it is sprayed from the nozzle to extinguish the fire. However, the system needs an additional set of inflatable equipment, which has high one-time investment, complicated management and slow fire extinguishing speed.
Extended data:
Characteristics of dry automatic sprinkler system;
1. The dry system has no water in the pipe network behind the alarm valve, which can avoid the danger of freezing and water vaporization, and is not limited by the ambient temperature, so it can be used in some places where the wet system cannot be used.
2. The investment is higher than that of wet system. Because of the need of inflation, a set of inflation equipment is added, which increases the system cost.
3. The construction, maintenance and management of dry system are complicated, and there are strict requirements for the air tightness of pipeline. Usually, the air pressure in the pipeline should be kept within a certain range. When the air pressure drops to a certain value, it needs to be inflated.
4. It is slower than the wet sprinkler system, because after the nozzle is heated and turned on, the gas in the pipeline must be discharged first, and then the water is discharged, which delays the opportunity.
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