When is it necessary to install an internal fire water supply and how to properly install it? What you need to know to do everything right? These questions will be answered by the article.
When ERW is required in a building
The list of requirements for a joint venture for internal fire water supply is indicated in a number of regulatory documents of VP 10.13.130 2009.
Mandatory installation of the pipeline :
- In residential and public buildings.
- In administrative and domestic buildings.
- At industrial enterprises.
- In production warehouses.
When determining the flow rate, knowledge of the number of storeys and the volume of the structure is required. In residential premises, the length of the corridor is taken into account.
In industrial buildings and warehouses, the level of fire resistance of a building, the degree of fire safety and the volume of a particular room are taken into account.
In industrial buildings and warehouses, if the height is more than 50 m, and indicators are indicated with a volume of up to 50 thousand m 3 , the use of four-jet pumps with a pressure of 5 l / s is recommended. If the volume of the room is higher, the use of eight-jet models is recommended.
To determine the amount of water used for fire fighting, it is necessary to take into account the indicators of the height of the compact jet and the diameter of the spray. With the free pressure of the fire hydrant, it is necessary to achieve a compact jet, the height of which will extinguish the fire at the highest point of the building.
Characteristics of fire water supply B2
Water supply B2 is necessary in order to extinguish fires with water. In accordance with the requirements of regulatory documentation, such a system should be installed:
- In residential buildings with a number of storeys from 12 and above.
- In the buildings of management structures with a number of storeys of 6 or more levels.
- In club and theater rooms, where there is a stage, cinemas, in the assembly and conference halls, which are equipped with appropriate examples of cinema equipment.
- In dormitory buildings, at public facilities, the volume of which is more than 5 thousand m 3 ;
- In administrative and domestic buildings at industrial enterprises, with volumes from 5 thousand m 3 .
Features of the scope of application of CB B2 equipped with a set of fire hydrants
According to regulatory documents, the installation method of the B2 system is subordinate to the B1 and B3 systems. From this it follows that if there is a B1 or B3 network at the facility, it is necessary to connect the B2 water supply pipe to the riser of the B1 or B3 network.
The diameter of the risers B2 should be at least 50 mm. The zone of their placement is the territory of the staircase and the corridor. The location of fire hydrants with a diameter of 50 mm requires a level of 1.35 m above the floor surface.
Their location is lockers. It is important to have a rolled-up hemp fire hose, the length of which is from 10 to 20 m. One end of the sleeve is equipped with a half-nut in order to quickly connect it to the fire hydrant device. The other end is equipped with a conical fire barrel to receive a compact water stream, the length of which is from 10 to 20 meters.
How to determine the required amount of water for ERW
It is important to consider the nature of the individual characteristics of the object. If this is a production warehouse building, where all fire-fighting water supply devices with a diameter of 100 and a unit weight of kg are installed, it is recommended that the minimum flow rates be increased in accordance with the requirements of regulatory documents. For this, frame steel structures can be used.
Pipeline frost protection
If in winter a well or a plastic pipe of an external fire water pipe freezes, you can connect an electric cable to the pipes in severe frosts. When installing the system, it is allowed to use additional insulation with special materials. Necessary to provide frost protection for fire water supply.
External pipes and water supply can be insulated with foil tape and a voltage cable, which consists of three cores. The foil serves as a heat sink and does not allow overheating. Wrap the pipe with insulation. So that there are no loads in the trench where the pipeline is located, it is concreted.
All fittings are clean, it is recommended that they be additionally coated with an anti-corrosion compound or painted. Before sticking tape, the pipe must be cleaned of dust and dirt.
There is a faster, but not so convenient way. Cut strips of foil isol or isospan, glue them with tape.
You can wrap several layers of mesh on the pipe, coat with glue and wrap around insulation. This is the most reliable way to protect against freezing of a fire pipe, designed for long-term operation.
Where are fire hydrants used?
This system is known for extinguishing fires for more than 200 years. The fire brigade always has the nearest hydrant at its disposal. Its presence is mandatory in every area. Their accessibility, ease of use and visibility on the territory are important.
Hydrants located in the residential area must supply a stream of water of 5700 l / min. GHGs must be located along the length of the road, 2.5 m from its edge and up to 5 m from the wall of a nearby building.
It is forbidden to install it on the territory that is intended for the movement of cars and on branches from pipelines. It is necessary to install a fire hydrant so that at any time it is possible to extinguish the fire at the facility that is assigned to this network. It is important that there are at least two hydrant hoses with water flow rates for external fire extinguishing from 15 l / s.
About the device of the internal water supply
Norms SN and P regarding the internal water supply and sewage system of the facility are provided in order to design systems that are just under construction and to reconstruct existing ones:
- domestic water supply;
- sewage system;
- gutters.
Mounting Features
The piping can be fixed by supporting it on the wall and partition in the area of the mounting hole. You can rely on the basement floor through the places of concrete or brick columns, brackets along the entire length of the wall and partition. The pipeline is also supported on suspensions to the surface of the floors.
During the installation of the fire water supply, if the pressure of the fire hydrant is over 40 m, a diaphragm is provided between it and the parts of the connecting head. This will be required to reduce overpressure. You can install diaphragms with the same hole diameter on buildings of three or four floors.
Between the floor and the highest point of overlap there must be a distance of at least that indicated in the table:
| Building height | Type of construction | Fire Jet Length |
| Up to 50 mm | Residential, public, industrial and auxiliary buildings of industrial enterprises | 6 m |
| More than 50 mm | Residential buildings | 8 m |
| More than 50 mm | Public, industrial and auxiliary buildings of industrial enterprises | 16 m |
How to make a calculation for ERW in the HydRaVPT program
If there is a regular internal fire water supply system, which consists of taps and pipes, you can calculate how to install it through the Internet program. The calculation results are flow and pressure indicators.
Consider the scheme of SP 10 13130 internal fire water supply. To calculate the necessary parameters, we introduce the number of cranes that are required by standards.
We switch to the program and indicate that there are, for example, 2 jets of 2.5 liters. Room height - 3 m, crane marks - 1.35 m, no control unit. Let us depict a ring with a diameter of 50 mm and a dead end. The diameter of the pipeline is 65-80 mm.
We enter all the data, do not change anything in the "Normal section" section, as these indicators suit us. We introduce the number 0.000005 and simulate a formal sprinter sprinkler - a red dot at the top of the screen. It will not be taken into account in the program, but this item is required.
We introduce the geometric height of the dictating sprinkler 3 m, the height of the control unit and the coefficient - 0, 2 cranes of 2.5 l. We choose the minimum diameter for determining the branch pressure - 0.001. The calculations take into account local pressure losses. We open the section "Fire crane. Pipeline". We select and substitute automatically the value of the fire hydrant. 2.6 l / s, 0.1 MPa, a 50 mm crane are standard indicators that can be used in our calculations. We confirm the entered indicators and proceed to the choice of the diameter of the fire hydrants. We enter an indicator of 50 mm. For supply pipelines - 67 mm.
Finish by determining the length of the plots. The first is the distance to the fire hydrant. We introduce the indicators of 2 m at a height of 1.65, since this fire water supply has a downward direction. The length of the annular pipeline is 3 m. We introduce the same indicators for the second crane.
The whole system is entered, click "Finish", and the program will automatically calculate the necessary indicators.
To summarize
Fire water supply system is an obligatory device for ensuring fire safety of buildings and other territory. The installation of such a system implies compliance with the requirements specified in the normative documentation on the ERW system.