Selection of nozzle:

The installation height of the closed nozzle should meet the condition of "timely heating and opening of the nozzle, and covering the fire area with the sprinkler of the open nozzle". Beyond the above height, the nozzle will not be able to be heated and opened in a timely manner, and the sprinkler after the nozzle is opened may not achieve the expected purpose of covering the fire area, resulting in the phenomenon of fire spreading outside the sprinkler range, making the system unable to play its role in controlling and extinguishing the fire.

Regulations on nozzle selection under different usage conditions. In practical engineering, the phenomenon of errors caused by improper selection of nozzles is quite prominent. Nozzles with different purposes and models have different usage conditions and installation methods. The selection, installation method, and reasonable orientation of the nozzle will directly affect the action time and water distribution effect of the nozzle. When the installation site does not have a suspended ceiling and the water distribution pipeline is arranged along the beam, the hot air flow of the fire will spread horizontally after rising to the roof. At this point, only by installing an upright nozzle upwards can the hot air flow come into contact with and heat the thermal sensor of the nozzle as soon as possible. When there is a suspended ceiling indoors, the nozzles will be arranged tightly under the ceiling or buried inside the ceiling, so it is suitable to use hanging or suspended ceiling nozzles, otherwise the ceiling will block the distribution of water spray.

The water distribution pipeline with side wall type extended coverage nozzles is easy to arrange and is popular among domestic design, construction, and usage units.

⑶ In order to facilitate the drainage of accumulated water in the pipeline before the system is put out of fire or restored to alert state after maintenance, and to facilitate exhaust during system startup, it is required that the nozzles of dry and pre action systems use upright nozzles or dry drooping nozzles.

⑷ Requirements for nozzle selection of water curtain system. The function of fire separation water curtain is to block the spread of smoke and fire. When forming a densely sprayed water wall with a water curtain, it is required to use sprinkler heads; When forming a dense spray water curtain, it is required to use water curtain nozzles with downward openings. Fire separation water curtains can also use both types of nozzles and be arranged in separate rows. The protective cooling water curtain requires the use of water curtain nozzles that spray water towards the protected object.

⑸ Quickly respond to the usage conditions of the nozzle. The use of a large amount of modern daily necessities and office supplies such as decorative materials and household appliances has led to new characteristics such as fast spread of fires, large generation of harmful gases, and increased value of property damage. This has raised higher requirements for the working efficiency of automatic sprinkler fire extinguishing systems, which require the use of fast response nozzles.

To prevent the mixing of different nozzles from causing adverse effects on the startup and operation of the system, nozzles with consistent thermal performance, specifications, and installation methods should be used in the same compartment.

When designing an automatic sprinkler fire extinguishing system, it is required to specify the quantity of spare nozzles in the design data, so that after the system is put into use, if the nozzles are damaged due to fire or other reasons, they can be replaced in a timely manner, shortening the time for the system to restore its alert state.

Key points for construction and installation of nozzles:

1) The installation of the nozzle should be carried out after the system pressure test and flushing are qualified.

2) Special elbows and tees should be used for nozzle installation.

3) When installing the nozzle, it is not allowed to disassemble or modify it, and it is strictly prohibited to add any decorative coating to the nozzle.

4) Special wrenches should be used for nozzle installation, and it is strictly prohibited to use the nozzle frame for tightening; When the frame and splash box of the nozzle deform or damage the released components, a nozzle with the same specifications and model should be replaced.

5) When the nominal diameter of the nozzle is less than 10mm, a filter should be installed on the water distribution main or pipe.

6) Spray heads installed in areas prone to mechanical damage should be equipped with spray head protective covers.

7) When installing the nozzle, the distance between the splash box and the ceiling, door, window, opening or wall should meet the design requirements.

8) When the spray nozzle splash plate is higher than the nearby beam bottom or the ventral surface of the ventilation duct with a width less than 1.2m, the large vertical distance of the spray nozzle splash plate above the beam bottom and the ventral surface of the ventilation duct should comply with the relevant standards.

9) When the width of the ventilation duct is greater than 1.2m, the nozzle should be installed below its belly surface.

10) When the nozzle is installed near a partition that does not reach the top, the horizontal distance and small vertical distance between the nozzle and the partition should comply with the relevant standards.