Description and Applications
The hydrant network is made up of a fixed piping system for water supply on which derivatives are one or more fire hydrants, complex hydrants, fire hoses, pump connections, hydrants topsoil and subsoil, etc.. The network is connected to one or more power supplies water through a manifold; to the same network can be connected fire hydrants consist of a unified attack, equipped with a shut-off valve with manual opening.
Moisturizing network hydrants must be accompanied by one or more attacks of delivery trucks for the Fire (Motor pump connections), consisting of a valve and a non return and provided also being unified attack for fire fighting hoses ( hoses). Such attacks have a function of water supply subsidiary and must comprise: one or more intake ports 70 to UNI walker with filter, to prevent the entry of foreign bodies in the network, a shutoff valve which allows the operation on the parts without draining the system, a non-return valve or other device suitable to prevent the outflow of water from the pressurized.
The water supplies must be carried out so as to maintain efficient and well functioning system, so they should assure the flow and pressure required.
The norm UNI 10779 defines the minimum requirements that the network must have fire hydrants from the point of view of the design of both the installation and operation, introducing the criterion of the distinction between internal and external protection, considering the network hydrants as a true fixed system of protection against fire, having one of its organic constitution.
The buildings with eaves height, more than 45 meters, but do not fall within the scope of the UNI 10779, also not covered by the existing outdoor activities because there is the danger of frost may create problems of functionality and in cases where it is permissible to be connected directly to the network with the water service activity.
The UNI 9490 contains, among other requirements which must be fulfilled for the pipes above ground and underground installations. The shut-off valves must be of the type that indicates the position of opening / closing or UNI 6884 type gate UNI 7125. With regard to these underground hydrants must be properly marked and should not be able to hinder in any way the use.
The installation of a network hydrant entails that the pipes have to be installed taking into account the reliability that the system must offer; the ring closure of the main manifolds and the installation of valves in suitable positions constitute one of the criteria for the achievement of the required level of reliability to the system.
The piping network hydrants must be able to be emptied without the need to dismantle the most significant components and shall not be exposed to damage. The frost is a problem that should not be underestimated, in fact, in places where the winter temperature can drop below freezing, it is necessary that the pipes, where it is not possible to do otherwise, prove suitably protected against this risk with insulating materials. Networks hydrants to be installed in areas defined seismic grade I, II and III ° shall be such as to withstand earthquakes without taking breaks.
When the pipes of the hydrant network through vertical and horizontal structures of the building must be implemented the necessary precautions to prevent the deformation of the pipes or damage to components due to expansion or structural failure. In each case the supports of the pipes of the network must be non-combustible; the collars must be closed around the pipes and must not be used supports open. In the standard are the diameters, the section and the thickness that must have backups.
The hydrants stand shall be placed at a maximum distance between them does not exceed 60 meters and its maximum distance from the outer walls of buildings should be between 5 and 10 meters.
With respect to hydrants wall (complex hydrant), they must be installed so that each complex is able to protect not more than 1000 square meters and that each point of the air protected distance of no more than 20 meters from it.