The DIN 1988-600 that was published in December 2010 replaced the former Part 6. It is valid for the planning, construction, operation, modification and maintenance of drinking water installations from the connection point to the extinguishing wa-ter transfer point (EWTP) and for over-ground and underground hydrants when connected to drinking water installations on land sites. The planning and execution of extinguishing systems is now only in-cluded to a restricted extent. As a counter-move, the DIN 14462 was supplemented accordingly (Norm draft 2010-12).

Differentiation between the connection types

The DIN 1988-600 now defines the inter-face between the drinking water installati-on and the fire extinguishing and fire pro-tection system as an extinguishing water transfer point (EWTP) for the first time. He-reby, a differentiation is made between in-direct (free outflow type “AA“ or “AB“ in accordance with DIN EN 1717) and a di-rect connection. The direct connection is only permitted to a restricted extent as a special case. These include the following extinguishing water transfer points that are equipped with the following fittings:

• Filling and drainage station in accor-dance with DIN 14463-1 for systems with wall hydrant types “F” and “S” and for overground hydrants,

• Filling and drainage stations in accor-dance with DIN 14463-3 for systems with open nozzles

• Direct connection stations in accor-dance with DIN 14464 for sprinkler and water spray extinguishing systems,

• Hose connection valves in accordance with DIN 14461-3 for wall hydrant type “S“,

• Underground and overground hydrant in accordance with DIN 14384 DIN or EN 14339 respectively.

The following has validity for both the direct and the indirect connection:

the drinking water withdrawal for the object protection is not to pose a risk to the minimum pressure level in the supply net-work. If the wa-

ter utilities company should only supply a partial amount of the required extin- guishing water, the difference is to be stored. This requires an indirect con-nection type however, as the connection of a non-drinking water system with a drinking water system is not permitted. Indirectly connected fire extinguishing and fire protection systems can also be supplied from fire engines, streams or

ponds used for firefighting. A direct drinking water connection is permissible for self-help equipment in connection with wall hydrant type “S“ if the peak volume flow of the drinking water system should be higher than the needs of the extin- guishing water system. Connections to an external feed are not permissible in this case.

Planning and executing the connection pipe

If drinking water is used as extin- guishing water, the extinguishing water and the consumer appliances are to be supplied from a shared connection pipe. The DVGW worksheet W 404 has validi-ty for the planning and execution of the shared connection pipe. The dimensioning is to be carried out in accordance with DIN 1988-300 corresponding to the peak drinking water volume flow with a flow velocity of maximum 2 m/s. Maximum 5 m/s are permissible in the event of a fire breaking out. This requires the approval of the water utilities company however. The consumption is recorded by a shared water meter.

The EWTP should be located as close to the meter as possible. This requirement is important for many reasons: the pres-sure reducer, mechanical filter and stone catcher that are required for drinking wa-ter installations are not to be installed in the shared feed pipe. The consequence of this is that the supply for the drinking wa-ter system is to be connected immediately downstream from the water meter and the stipulated backflow preventers.

The section from the branch in the drin-king water feed pipe to the EWTP is de-

Parallel to the development of DIN EN 806, Technical Rules for Drinking Water Installations, supplementary norms were worked on in order to do justice to the higher national requirements. Labelled with three-digit parts numbers, these were summarised with the completion of the DIN EN 806 as the new DIN 1988. As the structure of the DIN EN 806 differs from that of the former DIN 1988, the structure makes changes to the scopes of validity necessary. This also has validity for the DIN 1988-600. It defines the requirements for the connection of fire extinguishing and fire protection systems to drinking water installations.

Design of the Drinking Water Connections in Connection with Fire Extinguishing and Fire Protection SystemsPlanning in accordance with DIN 1988-600

Der unmittelbare Anschluss ist als Sonderfall nur

eingeschränkt zulässig.

80 IKZ-HAUSTECHNIK Sonderheft Trinkwasserhygiene 2013

Mittelbarer und unmittelbarer Anschluss an das Trinkwassernetz. Bild: GEP

“F” or “S”. Transfer point: free outflow type “AA“ or “AB“ in accordance with DIN EN 1717.

• System type: “wet-dry“ extinguishing water system with wall hydrant types “F” or “S”. Transfer point: free outflow type “AA“ or “AB“ in accor-dance with DIN EN 1717 or a filling and drainage station in accordance with DIN 14463-1. (Observe the peak volume flow during the filling phase.)

Note: DIN 14462 stipulates that the re-motest hydrant is to be able to supply ex-tinguishing water with adequate pressu-re after 60 seconds. The flow volumes and the minimum flow pressure rates stipula-ted in DIN 14462 have validity for the di-mensioning of the extinguishing water pi-pes. These are 24 l/min and 0.2 Mpa (2 bar)

for a type “S” wall hydrant. The norm assumes that a minimum of two hydrants need to be supplied simultan- eously. Analogue to this, 100 l/min and 0.3 MPa (3 bar) have

validity for wall hydrant type “F“ with a simultaneous withdrawal from three hy-drants.

signated as being a single feed pipe. Its length is to be restricted to a maximum of 10x DN in addition to a volume of 1.5 l not being exceeded. Otherwise, an automatic rinsing device is required that is to en- sure the weekly exchange of a minimum of triple the water volume of the single feed pipe. The rinsing device is then to be so di-mensioned that a minimum flow velocity of 0.2 m/s is to be ensured with nominal widths of ≤ DN 50, a minimum of 0.1 m/s being required for nominal widths of ≥ DN 50. These requirements form the basis for the hygienic design of the EWTP.

System types and their transfer points

The allocation table in DIN 1988-600 shows the system types, their connec-tion types and the demands placed on the EWTP:

• System type: sys-tem with an ad-ditional feeding of non-drinking water. Transfer point: free out-flow type “AA“ or “AB“ in accor-dance with DIN EN 1717.

• System type: “wet“ extinguishing wa-ter system with wall hydrant types

Löschwasserleitung „nass” oder „nass/trocken”: Die Versorgung der Trinkwasseranlage muss un-mittelbar nach dem Wasserzähler und dem vorgeschriebenen Rückflussverhinderer eingebunden werden. Bild: Brandag

Die Trinkwasserentnahme für den Objektschutz darf den Mindestdruck im Versorgungsnetz nicht gefährden.

• System type: drinking water instal-lations with wall hydrant type “S” in accordance with DIN 14462. Transfer point: DN 25 hose connection valve with an integrated safety combina-tion comprising a pipe aerator and a backflow preventer in accordance with DIN 14461-3.

Note: The hose connection valve re-quires a DVGW test mark as proof that it is suitable for use in drinking water sys-tems. This version is a form of self-help as a special case. Hereby, the wall hydrants are integrated in the shared standpipe of the drinking water system. The single feed pipe to the EWTP is to have a maximum of 10 x DN. In self-help devices in combina-tion with wall hydrant type “S“, the feed depends on the peak drinking water vo- lume flow, that needs to be higher than the needs of the extinguishing water needs. The calculation of the flow rate is to be based on 2 x 24 l/min. This means that the peak drinking water volume flow that is required for the dimensioning of the standpipe is to be ≥ 0.8 l/s.

• System type: fire extinguishing and fire protection systems with open nozzles and sprinkler systems. Transfer point: free outflow type “AA“ or “AB“ in accor-dance with DIN EN 1717. Filling and drainage stations in accordance with DIN 14463-2 or direct connection sta-tions in accordance with DIN 14464 are also permissible as an alterna- tive.

Note: extinguishing systems with open nozzles are normally designed for a large effective range and cause high peak volu-me flows in case of a fire occurring that can easily exceed 30 l/s. This is why the peak volume flow is to be observed at the transfer point and the filling and draina-ge station. Direct connection stations are directly connected to the drinking water installation. The securing is in the form of a special fittings combination. This soluti-on is also a special case and is exclusively intended for sprinkler systems. The extin-guishing water stagnates should no drin-king water be fed into the pipe. The basis for the water need in case of fire is not to exceed 50 m3/h. This means that the peak drinking water flow should be ≥ 13.88 l/s, whereby the possibilities of use of a direct connection station is therefore additional-ly put into perspective.

• System type: selectively acting sprink-ler system. Transfer point: free outflow

Sonderheft Trinkwasserhygiene 2013 IKZ-HAUSTECHNIK 81

PlANUNg

such as a system for the feeding of tanks for industrial and agricultural use.

SummarySafety separation stations normally suf-

fice for most household applications. They are also equipped with a connection that enables the fire brigade to feed water in should there be a high demand for extin-guishing water. The device concept ena-bles existing extinguishing systems to be subsequently disconnected from the drin-king water system. The following passa-ge in DIN 1988-600 is important in this regard: “Should the requirements of the TrinkwV not be met, then there is no pro-tection of a drinking water installation that is connected to a fire extinguishing and fire protection system“. When working on the drinking water installation, the speci-alised craftsman has an obligation in ac-cordance with ATV DIN 18381 (VOB C), to provide notification of any discernible de-ficiencies. In the interest of drinking water hygiene however, an expedient notification to the operator of the drinking water sys-tem is also justified even if a contract for services should not have been concluded.

Author: Martin Pagel, Seminar Leader for Drinking Water Technology at Honeywell Haustechnik

and design can be presented taking the “CBU“ station from Honeywell as an exam- ple. The combination of a storage vessel and a single or double pump system works fully automatic. The storage vessel is loca-ted on the inlet side and has an effective volume of 540 or 1080 l, depending on the versions. The water is backfed via the free outflow type “AB” and a motor-controlled butterfly valve. Three float switches moni-tor the water level in the vessel. This con-trols the backfeed in addition to a lack of water and an overflow being reported. The highest performance version provides for a conveying volume flow of max. 36 m³/h and max. conveying heights of 143 m on the outlet side. This safety separation stati-on that has been designed for industrial ap-plications meets with the requirements of DIN EN 1717 and those of norms DIN 1988-600, DIN 14462 and DIN 13077 that have validity for fire extinguishing devices. This provides for additional possibilities of use

type “AA“ or “AB“ in accordance with DIN EN 1717 or a direct connection sta-tion.

Note: the peak drinking water volume flow is again decisive when using the di-rect connection station here. It is also to be taken into account that the design vo-lume flow of the direct connection station is restricted to a maximum of 50 m3/h. The flow velocities in the connection pipe are not to exceed 2 or 5 m/s respectively.

• System type: systems with underground and overground hydrants. Transfer point: free outflow type “AA“ or “AB“ in accordance with DIN EN 1717. Fil-ling and drainage stations in accor-dance with DIN 14463-1 (when taking the peak volume flow into account) and overground and underground hydrants in accordance with DIN EN 14339 and DIN EN 14384 as long as an adequate amount of water flows through the drin-king water installations.

Protective separation station as a connecting link

In practice, a free outflow type “AA“ and “AB“ are the only variants for the transfer point between drinking water installations and fire extinguishing and fire protection systems. It is normally the case that type “AB“ is used, this being installed in pro-tective separation stations. The function

UNTErSCHEIDUNg DEr WANDHyDrANTEN TyP S UND F

Die Wandhydranten Typ S und Typ F unterscheiden sich hauptsächlich in Bezug auf die Durchflussmengen und die Verwendung. Während der Wandhydrant Typ S mit einem formstabilen Schlauch für jedermann bestimmt ist, kann Typ F sowohl für die Selbsthil-fe als auch von der Feuerwehr verwendet werden. Er ist zudem für größere Durchfluss-mengen ausgelegt. Im Gegensatz zu Typ S, der bei einem Mindestfließdruck von 2 bar eine Durchflussleistung von 24 l/min besitzt, ist der Wandhydrant Typ F für Durchflussmengen von 100 l/min bei einem Mindestfließdruck von 3 bar bzw. 200 l/min bei 4,5 bar geeignet.

Der Wandhydrant Typ F ist für die Nutzung als Selbsthilfe sowie für die Nutzung der Feuerwehr vorgesehen. Er ist für Durch-flussmengen von bis zu 200 l/min geeignet. Bild: Gloria

Der Wandhydranten Typ S ist für jedermann bestimmt und besitzt eine Durchflusslei-stung von 24 l/min. Bild: Gloria

Sicherheitstrenn station CBU von Honeywell. Bild: Honeywell

Beispiel eines mittelbaren Anschlusses mit vorgeschalteter Verbrauchsleitung. Die Einzelzuleitung ist auf maximal 10 x DN begrenzt. Bild: Gloria

82 IKZ-HAUSTECHNIK Sonderheft Trinkwasserhygiene 2013