Construction and installation of fire nozzles
(1) The installation height of the closed nozzle is required to meet the conditions of “make the nozzle open in time by heating, and make the sprinkler of the open nozzle effectively cover the fire range”. Exceeding the above height, the nozzle will not be able to be heated and opened in time, and the spraying water after the opening of the nozzle may not achieve the expected purpose of covering the fire range, and the phenomenon of fire spreading outside the spraying range will occur, so that the system cannot effectively control and extinguish the fire.
(2) Regulations on nozzle selection under different conditions of use. In actual engineering, the phenomenon of mistakes caused by improper nozzle selection is more prominent. Different uses and types of nozzles have different usage conditions and installation methods. The selection, installation method and orientation of the nozzle are reasonable or not, which 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 pipes are arranged under the beams, the hot air flow of the fire will spread horizontally after rising to the ceiling. At this time, only the vertical nozzle is installed upwards, so that the hot air flow can contact and heat the nozzle thermal element as soon as possible. When there is a ceiling in the room, the nozzles will be arranged close to the ceiling, or buried in the ceiling, so it is suitable to use drooping or ceiling-type nozzles, otherwise the ceiling will block the water distribution.
(3) In order to facilitate the system to remove the accumulated water in the channel before returning to the alert state after fire fighting or maintenance, and also to facilitate the exhaust when the system is started, the nozzles of the dry and pre-action systems are required to use upright nozzles or dry pendent nozzles. .
⑷ Nozzle selection requirements for water curtain system. The function of the fire separation water curtain is to block the spread of smoke and fire. When the water curtain is formed into a densely sprayed water wall, a sprinkler nozzle is required; when the water curtain is formed into a densely sprayed water curtain, a water curtain nozzle with an opening downward is required. The fire separation water curtain can also be arranged side by side by using the above two nozzles at the same time. The protective cooling water curtain requires the use of water curtain nozzles that spray water on the protected object.
⑸ Quick response to the conditions of use of the nozzle. The use of a large number of decorative materials, home appliances and other modern daily necessities and office supplies has led to new characteristics such as rapid fire spread, large amount of harmful gas generation, and increased value of property losses, which has put forward higher work efficiency of automatic sprinkler systems. If required, use quick-response nozzles.
⑹To prevent the mixing of different nozzles from causing adverse effects on the startup and operation of the system, nozzles with the same thermal performance, specifications and installation methods should be used in the same compartment.
⑺ When designing an automatic sprinkler system, the number of spare nozzles is required to be stated in the design data, so that after the system is put into use, when the nozzle is damaged due to fire or other reasons, it can be replaced in time and shorten the time for the system to return to the alert state.
Fire nozzle construction and installation points
1) The nozzle installation 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 the nozzle is installed, it is not allowed to disassemble or modify the nozzle, and it is strictly forbidden to attach any decorative coating to the nozzle.
4) A special wrench should be used for the installation of the nozzle, and it is strictly forbidden to use the frame of the nozzle to screw; when the frame of the nozzle and the splash plate are deformed or the original parts are damaged, the nozzle with the same specification and model should be used for replacement.
5) When the nominal diameter of the nozzle is less than 10mm, a filter should be installed on the water distribution main pipe or water distribution pipe.
6) Nozzles installed in places susceptible to mechanical damage should be equipped with nozzle guards.
7) When the nozzle is installed, the distance between the splash plate and the ceiling, door, window, opening or wall should meet the design requirements.
8) When the nozzle splash plate is higher than the bottom of the nearby beam or higher than the ventilated surface of the ventilation duct with a width of less than 1.2m, the maximum vertical distance of the nozzle splash plate above the bottom of the beam and the ventral surface of the ventilation duct shall 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 ventral surface.
10) When the nozzle is installed near the partition that is not at the top, the horizontal distance and the minimum vertical distance between the nozzle and the partition shall comply with the relevant standards.