Pressurization system: This term refers to a specific fire protection water supply solution based on one or more pumps connected directly to the water mains. Let’s see what this means and what is specified in the various editions of UNI EN 12845.*
Table of Contents
Pressure-boosting system: what it really means
A pressure-boosting system is a type of fire protection water supply system in which the pressure (the “boost”) is achieved by one or more centrifugal pumps connected directly to the water mains at the inlet.
In other words, we are not talking about a pump “downstream” of a private reservoir, but rather a connection that draws water from the municipal water main and pumps it back through one or more pumps dedicated to this function.
What did UNI EN 12845:2007 state (sections 8.6.3 and 9.2.2)?
The 2007 edition of UNI EN 12845 set forth in sections 8.6.3 and 9.2.2 the guidelines deemed necessary for the design and construction of this type of fire protection water supply system.
In the reference document, section 9.2.2 is also cited to provide context for the technical solution: centrifugal pumps and an inlet connection to the water supply pipeline, with specific instructions for systems with a single pump.
Centrifugal pumps with inlet from the water main
In a typical fire suppression system setup, the pumps are installed directly on the inlet side of the water main. This is a key feature because, unlike other configurations, the pump “draws” water from the water supply network.
This method of connection is precisely what makes it essential to address two aspects:
- the system configuration (for example, any bypass);
- the licensing conditions imposed by the water system operator.
Single-Pump System: Why a Bypass Is Needed
When there is only one pump, it is necessary to install a bypass, to be constructed as shown in the diagram referenced in the text.
In practice, this step is treated as a requirement to be considered during the system configuration phase, precisely because the individual pump represents a single point of operation/connection in the pressure-boosting system.
Authorization from the water utility operator: an essential requirement
To install a pressure-reduction system, it is required to obtain authorization from the water utility (water system operator).
This requirement is described as essential because, in this type of application, there is a risk that the water main could be placed under negative pressure. For this reason, connecting to the system without authorization is described as not only an administrative offense but also a criminal offense, as it puts public health at risk.
The Risk of Depression in Pipelines and Its Consequences for Drinking Water Systems
The text explains the critical issue: if the water main is used to carry drinking water (a situation that is common in Italy), negative pressure can create a risk that sewage from outside may enter the pipe, since the pressure inside the pipe would be lower than atmospheric pressure.
The stated consequence is a potential and dangerous contamination of the drinking water supply, with associated risks to public health. For the same reason, it should be noted that connecting a pump to a water main at the inlet is normally prohibited (strictly).
UNI EN 12845:2015 and UNI EN 12845:2020: What Has Changed in Section 9.2.2
According to the text, subsequent editions of the standard—specifically UNI EN 12845:2015 and UNI EN 12845:2020—have eliminated section 9.2.2 and retained only, in section 9.2, a note reminding readers of the need to request authorization from the operating authority for any connection to be made to a water supply pipeline.
Section 8.6.3, however, remains unchanged, as it still mentions the possibility of using a pressure-boosting pump. This leads to the practical conclusion that the pressure-boosting system is still listed as an option, but with explicit attention paid to the issue of authorization for the connection.
Pressurization System: Final Summary in 4 Points
In summary, the following points emerge:
- Boost pumps are permitted.
- Authorization from the water utility is required to connect to the water supply system.
- If the connection is to a drinking water source, even if authorized, it is considered a public health risk.
- If the connection is made to an industrial water supply system or a fire protection system, the pollution problem would be significantly reduced.
Conclusion
A pressure-boosting system is therefore a solution that uses pumps connected to the water supply network: it is technically feasible and still considered an option, but it is closely tied to the issue of obtaining authorization from the utility provider and to the challenges (especially in drinking water networks) associated with potential negative pressure in the pipeline.
