Spare quantity of water mist nozzles

In our daily lives, fire prevention and extinguishing equipment can be seen everywhere, among which water mist fire extinguishing devices are becoming increasingly popular in the fire protection industry. Water mist nozzles are one of the important components in the water mist fire extinguishing device. When purchasing the project, there are also requirements for the number of spare water mist nozzles. Generally, the number of spare nozzles is no less than 5. The following is the spare quantity and related design requirements of fine water mist nozzles:

1. Spare quantity of fine water mist nozzles

When designing water mist nozzles, the number of spare nozzles needs to be stated in the design data. This way, after the system is running, if nozzles are damaged due to fire or other reasons, they can be replaced in time, shortening the time it takes for the system to return to alert state. When designing with different types of nozzles, in addition to the total number of spare nozzles required, each type of nozzle must also have its own spare parts.

1. Design requirements: The water mist fire extinguishing system should store spare nozzles according to the model and specifications of the nozzles. Their number should not be less than 1% of the actual designed total number of nozzles of the same model and specification, and should not be less than 5 each.

2. Acceptance requirements: The spare quantity of nozzles of different models and specifications should not be less than 1% of the actual installed total, and the number of spare nozzles of each type should not be less than 5.

2. Layout requirements for fine water mist nozzles

1. For places where the environmental conditions are likely to cause the nozzle holes to be blocked, a nozzle with corresponding protective measures that does not affect the fine water mist spraying effect should be selected;

2. For the floor mezzanine of the electronic information system room, it is advisable to choose a sprinkler head suitable for low space;

3. The nozzle arrangement of the closed system should ensure that the fine water mist is sprayed evenly and covers the protected area, and should comply with the following regulations:

①The distance between the sprinkler head and the wall should not be greater than 1/2 of the maximum layout spacing of the sprinkler head;

② The distance between the nozzle and other obstructions should be confirmed to ensure that the obstruction does not affect the normal spraying of fine water mist by the nozzle; when it cannot be avoided, compensatory measures should be taken;

③The distance between the temperature-sensing component of the nozzle and the ceiling or the bottom of the beam should not be less than 75mm, and should not be greater than 150mm. When a suspended ceiling is installed in the venue, the sprinkler head can be placed close to the suspended ceiling.

4. The nozzle layout of the open system should ensure that the fine water mist is sprayed evenly and covers the protected area, and should comply with the following regulations:

①The distance between the sprinkler head and the wall should not be greater than 1/2 of the maximum layout spacing of the sprinkler head;

② The distance between the nozzle and other obstructions should be confirmed to ensure that the obstruction does not affect the normal spraying of fine water mist by the nozzle; when it cannot be avoided, compensatory measures should be taken;

③ For cable tunnels or mezzanines, the nozzles should be arranged at the upper part of the cable tunnel or mezzanine, and the fine water mist should be able to cover the entire cable or cable tray.

5. For open systems that use local application, the nozzle arrangement should be able to ensure that the fine water mist envelopes or covers the protected object or part. The distance between the nozzle and the protected object should not be less than 0.5m. When used to protect indoor oil-immersed transformers, the layout of the sprinkler heads should comply with the following regulations:

① When the height of the transformer exceeds 4m, the sprinkler heads should be arranged in layers;

② When the distance between the cooler and the transformer body exceeds 0.7m, a sprinkler head should be installed in the gap;

③The nozzle should not be directly aimed at the high-voltage inlet casing;

④ When an oil collection pit is set up under the transformer, the nozzle arrangement should be such that the fine water mist covers the oil collection pit.

Different types of fire extinguishing systems in the fire protection field have different requirements for the spare quantity of sprinkler heads. For example, in automatic sprinkler fire extinguishing systems, the number of spare sprinkler heads should not be less than 1% of the total number, and each model must not be less than 10; for water spray fire extinguishing systems, the spare quantity of sprinkler heads of different types and specifications should not be less than 1% of the total number of actual installations, and the number of spare sprinkler heads of each type should not be less than 5. Therefore, fine water mist sprinklers should be purchased according to the requirements.