Recent publication of the new standard, UNE 23500:2018, Fire Fighting Water Supply
In 2015, the technical committee CTN23 Fire Safety (PEFIPRESA is a participant) and the secretariat of TECNIFUEGO began the revision process for standard UNE 23500/2012.
It has been replaced recently after passing all the filters required and has been published under UNE 23500/2018.
In this revision, the standard includes a general improvement of the previous version, clarification of doubts and comments raised by the sector, the correction of errata, diagrams and clearer graphics. It also focuses on the revision of European references applicable to the framework of the water supply for fire extinguishing. Most importantly, it is aligned to European guidelines.
The main highlights in reference to the previous version are as follows:
1. The creation of Annex B (informative), describing the method to select the category and the supply class. This being in response to queries received in relation to the difficulties in understanding the corresponding tables in the 2012 version.
2. For a better understanding of the content within the standard, the order in which the WATER SOURCES and the WATER SUPPLY TYPES AND CONDITIONS appear have been switched respectively.
3. A lengthier and improved definition of sections 4.2.2. Inexhaustible Source and 4.2.3. Deposits, with more illustrated diagrams that include versions of cylindrical deposits, not contemplated in previous versions.
4. Tables to define the class of supply, presented in a more comprehensible manner and arranged in two ways: by type of source and another by supply class with a schematic figure.
5. Elimination of Annex C of Standard UNE 23500:2012. In the new version it is replaced by 6.4, it only applies to a simple supply and to systems of fire hydrants equipped (BIE) of any size.
6. Definition of the scope of voluntary options in addition to those required in the standard. For example, “Table 8 in section 6.4.1” specifies the conditions for cases of simple supply with diesel options differently to “table 6” that are used, generally, for superior or double supply.
7. Presentation of voluntary monobloc diesel options for simple supply (6.4), with a battery set and 3 start attempts, simplifying the general requirement for superior or double supply, with double battery play and 6 start attempts.
8. In the simple supply (6.4) to stop the main pump can only be done manually (Annex C of 2012 allowed manual or automatic).
9.Harmonization of alarm colours in accordance with Standard UNE-EN 12845. As UNE-EN 12845-2016 standard states that for the control of the diesel motor pump, the failures must be presented in yellow, the new version of the standard UNE 23500 is aligned with this and specifies the colours of the alarms and warnings with the following criteria:
GREEN: to represent normal operating states (e.g. presence of mains voltage).
RED: to represent warnings or pre-alarms of possible fire detection (e.g. pump on demand).
YELLOW: for faults and alarms of technical anomalies.
10. New section 6.5 Pump system in a superior or double supply that replaces section 6.4 Pumping system in the 2012 version, which was multipurpose with exceptions in Annex C. In this version, section 6.5 and its subsections refer only to supplies of superior or double class, or, of simple class, but with sprinklers.
11. New range on the flowmeter between 40% and 150% of Qn or Qnb, according to supply class. It is about having measurement devices in which the scale allows an adequate reading around the range of nominal flows and pressures needed.
12. The scope has been defined for the sectioning valves of the test circuit, requiring electrical supervision signal as long as it is not completely closed.
13. 5% more margin is required over the maximum power absorbed to determine the power of the electric motor in the curves of the pump with increased absorption power up to a maximum point and then decreasing.
14. Unattainable requirements have been removed, such as “permanently” available power supply. To fulfill this requirement there are those who thought that it was necessary to have an additional generator, in case there is a general breakdown of the electric company; but nobody guarantees that the generator does not fail. To embellish, we could install a nuclear power plant next to the equipment, in case the rest fail, but nobody guarantees that the nuclear power plant will not fail.
15. To alleviate the above problem and standardize the basic principle of keeping the power supply as operational as possible, the concept of “reliable” electricity supply is defined as something feasible and controllable.
16. Alternatives have also been given to requirements with difficulties in obtaining permits from third parties, such as the definition of the use of a publicly acceptable network.
17. The maximum number of deposits of reduced capacity has been defined independently of the supply class.
18.The possible locations of the pumping equipment have been expanded, more in line with the real possibilities of the facilities
19. The concept of “stable curve” of the pump has been defined, as indicated in the consultation versions of the draft Standard prEN 12259-12.
20. The definitions of impulse, nominal, suction pressure and its limits have been expanded and detailed (see 18.104.22.168.).
21. The “pressure sensor” concept has been made wider than the pressure switch, to introduce pressure transducers to enter, if in the future it is contemplated by other European standards (such as the UNE-EN 12845 standard).
22. It is possible to install the pressure sensors in series (as in the 2012 edition) or even in parallel, but with monitored systems to check the correct operation of both sensors.
23. A system is required to guarantee the locking in “automatic” mode of the main pump frames, in order to avoid handling errors.
24. In superior or double supply, the possible starts of the diesel engine have been reduced from 5 to 4, since two of them were redundant. In this version, it is aligned to the UNE-EN 12845 standard more.
25. Section 7.2 specifies the dimensioning of the pipes of the general distribution network in a more rational and technically acceptable manner.
26. In the documentation of the pumping equipment, the requirement to present the manufacturer’s original pump curves is added, independently of the test bench tests.
27. Taking into account the characteristics of these facilities and the current technical regulations regarding legionella, reference is made to the UNE 100030.
Source: Tecnifuego Issue Nº 48.
From PEFIPRESA, this is the culmination of the great collaboration and effort made by experts in the field (PEFIPRESA among others) to have prepare and publish the new version UNE 23500/2018. We hope appendix of Annex I, “List of UNE standards” of the new RIPCI (RD 513/2017), is updated by the Ministry of Industry as soon as possible.
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