The automatic sprinkler system is recognized as one of the most effective automatic fire extinguishing facilities in the world today, and it is the most widely used automatic fire extinguishing system with the largest consumption. The application practice at home and abroad has proved that the system has the advantages of safety, reliability, economy, practicality, and a high success rate of fire extinguishing.
The automatic sprinkler system has been applied abroad for more than 200 years. Automatic sprinkler systems have not only been applied in public buildings, workshops, and warehouses but also residential buildings in developed countries. The popularization and application of automatic sprinkler systems in building fire protection design can obtain huge social and economic benefits.
Set the fire hazard level of the site
- The fire hazard level of the installation place should be divided into light danger level, medium danger level (level I, level II), danger level (level I, level II), and warehouse danger level (level I, level II, level III).
- The fire hazard level of the installation site shall be determined after analyzing the fire characteristics and the difficulty of opening the sprinkler head and spraying water in place driven by the hot air flow according to its use, the fire load of the contained items, and the indoor space conditions. Classify according to Appendix A of this specification.
- When the fire hazard and fire extinguishing difficulty of various places in the building are quite different, the system selection and fire hazard level should be determined according to the actual situation of each place.
- According to the fire load (determined by the nature, quantity, and distribution of combustibles), indoor space conditions (area, height), the density of people, the difficulty of using an automatic sprinkler system to extinguish the initial fire, as well as evacuation and external reinforcement Conditions and other factors, classify the fire hazard level of the installation place. The nature and quantity of the objects in the building, as well as the density, packaging, and distribution of the structure, will determine the fire load and the burning speed and heat release in the event of a fire, which is an important factor for dividing the fire hazard level of the place where the automatic sprinkler system is installed. under.
General requirements for automatic sprinkler systems
The place where the automatic sprinkler system is set up shall comply with the provisions of the current relevant national standards.
The automatic sprinkler system is not suitable for places where many of the following items exist: 1. Items that explode or accelerate combustion when exposed to water; 2. Items that undergo violent chemical reactions or produce toxic and harmful substances when exposed to water; 3. Sprinkling water will cause Spilled or boiled liquid.
The design principles of the automatic sprinkler system shall meet the following requirements: - Fire detectors for closed sprinklers or start-up systems should be able to effectively detect initial fires;
- The wet system and dry system should start automatically after opening a sprinkler head. The pre-action system, deluge system, and water curtain system should use fire detectors and closed sprinkler heads as detection elements according to their types. start-up;
- Sprinklers that are open within the action area should continue to spray water within the specified time according to the spraying intensity selected by the design;
- When spraying water from the nozzle, it should be evenly distributed and should not be blocked.
Sprinkler System Components
Nozzle
Alarm valve group
Water flow indicator
Pressure switch
Terminal water testing device
Description of each component of the automatic sprinkler system - Nozzle:
1.1 For the sprinkler head of the closed system, its nominal operating temperature should be 30°C higher than the maximum ambient temperature.
1.2 The sprinkler type selection of the wet system should meet the following requirements: 1. For places without a suspended ceiling, when the water distribution branch pipe is arranged under the beam, the vertical sprinkler head should be used; 2. The sprinkler head arranged under the suspended ceiling should be a drooping type sprinkler head or ceiling-type sprinkler; 3. For residential buildings, dormitories, guest rooms of hotel buildings, wards and offices of medical buildings with horizontal roofs of light hazard level and medium hazard level I, side wall type sprinklers can be used; 4. Parts that are prone to collision Sprinklers with protective covers or ceiling-mounted sprinklers should be used; 5. Where a roof is a horizontal plane and there are no beams, ventilation pipes and other obstacles that affect the sprinkling of the sprinklers, sprinklers with expanded coverage can be used; 6. Residential buildings, dormitories, apartments, etc. Household sprinklers should be used in non-residential residential buildings; 7. Concealed sprinklers should not be used; if necessary, they should only be used in places of light hazard level and medium hazard level I.
1.3 The dry system and the pre-action system shall use vertical sprinklers or dry pendant sprinklers.
1.4 The nozzle selection of the water curtain system shall meet the following requirements: 1. The fire separation water curtain shall adopt the open type sprinkler or water curtain nozzle; 2. The protective cooling water curtain shall adopt the water curtain nozzle.
1.5 The automatic sprinkler protection cooling system can adopt the side wall sprinkler head.
1.6 Quick-response sprinklers should be used in the following places. When quick-response sprinklers are used, the system shall be wet. (1 public entertainment place, atrium ring corridor; 2 wards and treatment areas of hospitals and nursing homes, collective activity places for the elderly, children, and disabled; 3 floors beyond the water supply height of the fire pump connector; 4 underground commercial places.)
1.7 Sprinklers with the same thermal performance should be used in the same compartment.
1.8 The same sprinkler heads should be used in the protection area of the deluge system.
1.9 The automatic sprinkler system should have spare sprinklers, the number of which should not be less than 1% of the total, and each type should not be less than 10. - Alarm valve group
2.1 The automatic sprinkler system should be equipped with an alarm valve group. The closed system for protecting indoor steel roof trusses and other building components shall be provided with an independent alarm valve group. The water curtain system should be equipped with an independent alarm valve group or a temperature-sensitive deluge alarm valve.
2.2 For other automatic sprinkler systems that are connected in series to the main water distribution pipe of the wet system, independent alarm valve groups shall be installed respectively, and the number of sprinklers controlled by them shall be included in the total number of sprinklers controlled by the wet alarm valve group.
2.3 The number of sprinklers controlled by one alarm valve group shall meet the following requirements: 1. The wet system and the pre-action system should not exceed 800; the dry system should not exceed 500; only the sprinklers on the side with a larger number shall be included in the total number of sprinklers controlled by the alarm valve group.
2.4 The difference in elevation between the highest and lowest sprinkler heads for the water supply of each alarm valve group should not be greater than 50m.
2.5 The solenoid valve of the deluge alarm valve group should have a filter at its inlet. For the deluge system with deluge alarm valve groups installed in parallel, the entrance of the deluge alarm valve control chamber should be provided with a check valve.
2.6 The alarm valve group should be located in a safe and easy-to-operate place, and the height of the alarm valve from the ground should be 1.2m. The part where the alarm valve group is set should be equipped with drainage facilities.
2.7 The control valve connected to the inlet and outlet of the alarm valve should be a signal valve. When the signal valve is not used, the control valve shall be provided with a lock to lock the valve position.
2.8 The working pressure of the hydraulic alarm bell should not be less than 0.05MPa, and should meet the following requirements: 1. It should be installed near the place where people are on duty or the outer wall of the public passage; 2. The diameter of the pipe connected to the alarm valve should be 20mm, and the total length should not be greater than 20m. - Water flow indicator
3.1 Except that the sprinkler head controlled by the alarm valve group only protects the places on the same floor that do not exceed the area of the fire compartment, each fire compartment and each floor shall be equipped with a water flow indicator.
3.2 The sprinkler head under the roof in the warehouse and the sprinkler head built into the shelf shall be provided with water flow indicators respectively.
3.3 When a control valve is set before the inlet of the water flow indicator, a signal valve should be used. - Pressure switch
4.1 For the deluge system and the fire separation water curtain, the water flow alarm device should adopt a pressure switch.
4.2 The automatic sprinkler system shall use a pressure switch to control the pressure-stabilizing pump and shall be able to adjust the start-stop pressure - Terminal water test device
5.1 The most unfavorable point controlled by each alarm valve group shall be equipped with a terminal water test device at the sprinkler head, and other fire compartments and floors shall be equipped with a water test valve with a diameter of 25mm.
5.2 The water testing device at the end shall consist of a water testing valve, a pressure gauge, and a water testing connector. The flow coefficient of the water outlet of the test water joint shall be equal to the minimum flow coefficient sprinkler head on the same floor or in the fire compartment. The outlet water of the terminal water testing device shall be discharged into the drainage pipe through the outlet of the orifice, and the drainage standpipe should be provided with a top-extending vent pipe, and the diameter of the pipe shall not be less than 75mm.
5.3 The terminal water testing device and water testing valve should be marked, the height from the ground should be 1.5m, and measures should be taken not to be used by others.
