SIST EN 13079:2026

SLOVENSKI STANDARD
01-januar-2026
Naprave za preprečevanje onesnaženja pitne vode s povratnim tokom - Zračna
reža z injektorjem - Družina A - Tip D
Devices to prevent pollution by backflow of potable water - Air gap with injector - Family
A - Type D
Sicherungseinrichtungen zum Schutz des Trinkwassers gegen Verschmutzung durch
Rückfließen - Freier Auslauf mit Injektor - Familie A - Typ D
Dispositifs de protection contre la pollution de l'eau potable par retour - Surverse par
injecteur - Famille A - Type D
Ta slovenski standard je istoveten z: EN 13079:2025
ICS:
13.060.20 Pitna voda Drinking water
23.060.99 Drugi ventili Other valves
91.140.60 Sistemi za oskrbo z vodo Water supply systems
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 13079
EUROPEAN STANDARD
NORME EUROPÉENNE
November 2025
EUROPÄISCHE NORM
ICS 13.060.20; 91.140.60 Supersedes EN 13079:2003
English Version
Devices to prevent pollution by backflow of potable water
- Air gap with injector - Family A - Type D
Dispositifs de protection contre la pollution de l'eau Sicherungseinrichtungen zum Schutz des Trinkwassers
potable par retour - Surverse par injecteur - Famille A - gegen Verschmutzung durch Rückfließen - Freier
Type D Auslauf mit Injektor - Familie A - Typ D
This European Standard was approved by CEN on 18 May 2025.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 13079:2025 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Designation . 6
5 Symbolization . 6
6 Materials . 6
7 Requirements . 7
7.1 General. 7
7.2 Characteristics and tests . 7
7.2.1 General. 7
7.2.2 General tolerances and measurements . 7
7.2.3 Accuracy of measuring instruments . 7
7.2.4 Measurements . 7
7.3 Upstream feed orifice . 7
7.4 Downstream receiving orifice . 7
7.5 Receiving vessel. 8
7.6 Discharge from the intermediate zone . 8
7.7 Air gap (Distance “A”) . 8
7.7.1 General. 8
7.7.2 Single supply to a single receiving vessel . 10
7.7.3 Multiple supplies to a single receiving vessel . 10
7.8 Verification . 10
8 Marking . 12
9 Technical documents . 12

European foreword
This document (EN 13079:2025) has been prepared by Technical Committee CEN/TC164 “Water
supply”, the secretariat of which is held by AFNOR.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by May 2026, and conflicting national standards shall be
withdrawn at the latest by May 2026.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 13079:2003.
— terms and definitions have been adjusted;
— Clause 7.7, Air gap was revised by reducing the minimum size of the air gap;
— added an optional anti-splashing plate;
— validation procedure has been introduced;
— Figure 3 was divided in 2 figures and revised;
— the entire standard was revised editorially.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia,
Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland,
Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North
Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the United
Kingdom.
Introduction
In respect of potential adverse effects on the quality of water intended for human consumption, caused
by the product covered by this document, it provides no information as to whether the product may be
used without restriction in any of the Member State of the EU or EFTA.
NOTE Attention is drawn to existing national regulations concerning the use and/or the characteristics of this
product that can apply.
1 Scope
This document specifies the characteristics and the requirements of air gap with injector Family A,
Type D for nominal flow velocity not exceeding 3 m/s. Air gaps are devices for protection of potable water
in water installations from pollution by backflow. This document is applicable to air gaps in factory-
assembled products and to constructed air gaps in situ and specifies requirements and methods to verify
and ensure compliance with this document during normal working use.
The fluid in the receiving vessel is assumed to have similar properties to the water supply. Where this is
not the case, additional care or tests can be required to verify the efficacy of the solution in practical use.
The AD device is intended to be used in potable water installations according to EN 806 (all parts).
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN 806-1, Specifications for installations inside buildings conveying water for human consumption —
Part 1: General
EN 806-5:2012, Specifications for installations inside buildings conveying water for human consumption —
Part 5: Operation and maintenance
EN 1717, Protection against pollution of potable water in water installations and general requirements of
devices to prevent pollution by backflow
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 806-1 and EN 1717 and the
following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp/
— IEC Electropedia: available at https://www.electropedia.org/
3.1
air gap with injector Family A, Type D
permanent and horizontal distance between the upstream injector orifice and the downstream receiving
orifice, having an air break to drain and a receiving vessel
Note 1 to entry: See Figure 1 for the design principle.

Figure 1 — Design principle
3.2
upstream feed orifice
D
internal diameter size of the upstream injector orifice (or calculated from the equivalent cross-sectional
area)
3.3
downstream receiving orifice
pipework that receives the water directed across the full air gap from the upstream injector orifice and
discharges the water into the receiving vessel
3.4
receiving vessel
vessel that the downstream receiving orifice pipework discharges into and then supplies the downstream
pipework to process
Note 1 to entry: The receiving vessel is vented to atmosphere.
3.5
maximum incoming flow rate
maximum total flow rate determined by the sum of the individual flow rates of each inlet orifice for
multiple inlets
4 Designation
An air gap with injector Family A — Type D is designated by:
— name;
— reference to this document EN 13079;
— family and type;
— maximum operating flow rate (Q).
EXAMPLE Air gap, EN 13079, Family A — Type D, 14 l/min.
5 Symbolization
The graphic representation of the air gap with injector Family A — Type D is as follows (see Figure 2).

Figure 2 — Graphic symbol
6 Materials
All materials coming into contact with water intended for human consumption shall present no health
risk nor cause any change of the drinking water in terms of quality, appearances, smell, or taste. All
materials shall be compatible among themselves and with the water supplied and with the fluids or
substances that can come into contact with them.
There are no special requirements concerning the materials downstream of the feed orifice provided they
do not have any harmful effect on the upstream part or the overflow arrangement.
7 Requirements
7.1 General
The protection unit/device comprises four integral parts:
— upstream injector orifice;
— air break to drain or discharge to atmosphere;
— downstream receiving orifice;
— receiving vessel (container).
7.2 Characteristics and tests
7.2.1 General
Performance tests shall be carried out on the device as installed in accordance with the manufacturer’s
technical documents. If not specified, all tests shall be performed with water at an ambient temperature.
7.2.2 General tolerances and measurements
Flow rate and pressure: ± 2 % of the value specified.
Temperature: cold water: ± 5 °C of the value specified.
7.2.3 Accuracy of measuring instruments
All the measuring instruments shall have an error limit of ± 2 % of the measured value.
7.2.4 Measurements
All measurements shall be in mm or l/min unless otherwise specified.
7.3 Upstream feed orifice
The upstream feed orifice and its pipework shall be securely and rigidly fixed.
The direction of flow from the upstream feed into the downstream receiving orifice into air at
atmospheric pressure shall be in the range of +0° to −15° from the horizontal downwards.
The upstream feed orifice is positioned to discharge water horizontally across the air gap distance A.
No contact shall be observed between the upstream components and the downstr
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