Our expert responds #28

23 marzo 2021

by Idroelettrica spa

Sprinkler system connected and supplied directly from the water mains. What the standard provides and prescribes.

Question:

  • Can the sprinkler system be connected and supplied directly at the water mains of the aqueduct? What does the relevant legislation provide and prescribe in particular?
     
  • An estimate has been made of a necessary water flow rate of 10,000 litres per minute for at least 2 hours: could the operating authority of the aqueduct network guarantee water continuity for this flow rate without interruption of the service? What could be the adjustment measures to be carried out if the operating authority, while authorising direct connection to the network, cannot guarantee the estimated flow rate value?

Answer:

  • A sprinkler system can be supplied directly from an aqueduct – UNI EN 12845 9.1 and 9.2
  • Of course, the provisions of note 2 of point 9.2, regarding the authorisation to connect by the dispensing authority, apply.
  • Given that the approval to the connection of the operating authority has been acquired, it is necessary that the same issues a declaration in which it guarantees the continuity and reliability of the supply – UNI EN 12845 8.1.2
  • In the absence of such a declaration, according to the Systems Decree 4.1 

For the purposes of determining the continuity of the electrical power supply, the availability of the service can be attested by statistical data relating to previous years, similar to what is specified in the UNI 10779 standard for water supply. 
The certificates relating to the continuity of the water and/or electrical supply are issued by the supplying Authorities or by a fire-fighting professional.

This means, in this case, that the professional will guarantee that the aqueduct is able to deliver 10,000 litres/min for two hours at the project prevalence.

If neither the operating authority nor the professional wants to take responsibility for declaring the above, it goes without saying that the hypothesis of using the aqueduct as a water supply must be abandoned.

In that case, it will be necessary to switch to a system with a tank and pressurisation pumps.

IT
EN