The use of electric fire pumps is a topic that raises questions, especially when selecting (or verifying) the main pump for a sprinkler system. In this response, I clarify what is permitted and what is not, within the scope defined by UNI EN 12845.
Table of Contents
The question (and why it comes up so often)
The question is straightforward: Can vertical, multistage surface-mounted electric pumps be used as primary fire pumps?
Doubts often arise when an existing system already includes a pressurization unit, or when considering a “convenient” solution for the pump room. Here, however, the deciding factor is not market practice: it is what the rules require for the main pump.
The legal reference used in this response
The reference cited is Section 10.1 of UNI EN 12845:2016.
Based on this reference, a practical guideline can be established: verify which centrifugal machines are actually mentioned and which functional requirements are specified by the standard (particularly with regard to disassembly, maintenance, and inspectability).
Which main pumps are mentioned in the standard (according to the referenced section)?
Sticking to the point mentioned, the only centrifuges mentioned are:
- END SUCTION
- BACK PULL-OUT
This guideline is not “merely a preference”: it is linked to a specific operational requirement, as set forth in the same regulatory framework referred to above.
Electric fire pumps prohibited as primary pumps: which ones (in the case described)
From the above, it follows that:
- Vertical multistage pumps
- monoblock centrifugal electric pumps
They are not permitted as main pumps.
In other words: when we talk about prohibited electric fire pumps (within the scope of this question), the issue is not that they “don’t work,” but that they fail to meet the requirements that the rules associate with the END SUCTION / BACK PULL OUT type.
Why They Are Not Allowed: A Practical Explanation of the “Key” Requirement
The reason given (again in the reference to section 10.1) is to allow for:
- the pump and motor can be removed separately;
- the internal parts of the pump can be inspected or replaced;
- all of this takes place without affecting the inlet or outlet lines.
This clarifies the “why” behind the ban on electric fire pumps: it is not a general assessment, but a requirement related to the maintainability andaccessibility of the equipment over time, without affecting the piping.
What happens if the existing system has main pumps that are not covered by the rules?
A very specific example is the certification or periodic inspection of a water supply system that includes a pressurization unit with main pumps not covered by the rules.
In this situation, the text states that the technician must make a decision after verifying the pumps’ capacity to supply:
- the design FLOW RATE
- Project PREVALENCE
Following this review, the decision may be:
- keep the existing configuration, or
- Replace the machines with others that meet the criteria set forth in the regulations.
The key point here is the process: not a choice made “regardless,” but a choice based on an assessment of scope and prevalence and on compliance with the required criteria.
When the specified pumps can be used (without confusing their roles)
The text makes a clear distinction: the pump types listed above (multistage vertical and monoblock) may only be used as pressurization pumps.
So, if the uncertainty stems from a mixed system configuration, the rule of thumb to keep in mind is:
- Main pump: must comply with the specified criteria (END SUCTION / BACK PULL OUT);
- Pressurization pump: it may fall under the categories mentioned as being usable only for this purpose.
This distinction helps avoid the most common mistake: using a pump designed for pressurization as if it were a main pump, which falls under the typical case of electric fire pumps that are prohibited from being used as main pumps.
Conclusion
Based on the reference in Section 10.1 of UNI EN 12845:2016, vertical multistage surface electric pumps are not permitted as primary fire pumps, nor are monoblock centrifugal electric pumps. The criterion centers on the ability to remove the pump and motor independently and to inspect or replace internal parts without affecting the inlet and outlet lines.
