SIST EN 12729:2023
(Main)Devices to prevent pollution by backflow of potable water - Controllable backflow preventer with reduced pressure zone - Family B - Type A
Devices to prevent pollution by backflow of potable water - Controllable backflow preventer with reduced pressure zone - Family B - Type A
This document specifies the field of application, the dimensional, the physico-chemical, the design, the hydraulic, the mechanical, and the acoustic characteristics of controllable backflow preventers with reduced pressure zone Family B Type A.
This document covers controllable backflow preventers of Family B Type A, with reduced pressure zones, intended to prevent pollution of potable water by backflow, caused by backsiphonage or by backpressure.
It is applicable to controllable backflow preventers in denominations DN 6 up to DN 250.
It covers controllable backflow preventers of PN 10 that are capable of working without modification or adjustment:
- at any pressure, up to 1 MPa (10 bar);
- with any pressure variation, up to 1 MPa (10 bar);
- in permanent duty at a limited temperature of 65 °C and for maximum 1 h at 90 °C.
It specifies also the test methods and requirements for verifying their characteristics, the marking and the presentation at delivery.
Sicherungseinrichtungen zum Schutz des Trinkwassers gegen Verschmutzung durch Rückfließen - Systemtrenner mit kontrollierbarer druckreduzierter Zone - Familie B - Typ A
Dieses Dokument legt den Anwendungsbereich, die maßlichen und physikalisch chemischen Anforderungen, die Anforderungen an die Konstruktion, die hydraulischen, mechanischen und akustischen Anforderungen für Systemtrenner mit kontrollierbarer druckreduzierter Zone, Familie B, Typ A fest.
Das vorliegende Dokument gilt für Systemtrenner mit kontrollierbarer druckreduzierter Zone, Familie B, Typ A, die verhindern sollen, dass durch Rücksaugen oder Rückdrücken Wasser zurückfließt und dadurch Trinkwasser verschmutzt wird.
Es gilt für Systemtrenner der Nennweiten DN 6 bis DN 250.
Es gilt für Systemtrenner mit einem Nenndruck PN 10, die ohne Abänderung oder Nachstellung arbeiten:
- bei jedem Druck bis 1 MPa (10 bar);
- bei jeder Druckschwankung bis 1 MPa (10 bar);
- unter Dauerbelastung bei einer Grenztemperatur von 65 °C und für maximal 1 h bei 90 °C.
Die Norm enthält ferner Festlegungen für die Prüfverfahren und Anforderungen zum Nachweis dieser Eigenschaften, die Kennzeichnung und den Lieferzustand.
Dispositifs de protection contre la pollution de l'eau potable - Disconnecteur à zone de pression réduite contrôlable - Famille B - Type A
Le présent document spécifie le domaine d'application, les caractéristiques dimensionnelles, physico-chimiques, de conception hydrauliques, mécaniques et acoustiques de disconnecteurs à zone de pression réduite contrôlable de Famille B, Type A.
Le présent document s’applique aux disconnecteurs de Famille B, Type A à zone de pression réduite contrôlable, destinés à empêcher la pollution de l’eau potable par retour d'une eau par contre-pression ou siphonnage.
Il est applicable aux disconnecteurs contrôlables de dénomination DN 6 à DN 250.
Il s’applique aux disconnecteurs contrôlables de PN 10 qui doivent pouvoir fonctionner sans modification ni réglage :
- à toute pression, jusqu'à 1 MPa (10 bar) ;
- pour toute variation de pression, jusqu'à 1 MPa (10 bar) ;
- en service continu à une température limite de 65 °C et pendant 1 h au maximum à 90 °C.
Il spécifie également les méthodes d’essai et les exigences pour vérifier leurs caractéristiques, le marquage et la présentation à la livraison.
Naprave za varovanje pred onesnaženjem pitne vode zaradi povratnega toka - Sistemski ločevalnik z nadzorovanim območjem znižanega tlaka - Družina B - Tip A
Ta dokument določa področje uporabe, dimenzijske, fizikalno-kemijske, konstrukcijske, hidravlične, mehanske in akustične lastnosti preprečevalnikov povratnega toka s funkcijo krmiljenja z zmanjšanim tlačnim območjem družine B, tip A.
Ta dokument zajema preprečevalnike povratnega toka s funkcijo krmiljenja družine B, tip A z zmanjšanimi tlačnimi območji, ki so namenjeni preprečevanju onesnaženja pitne vode zaradi povratnega toka, ki je posledica povratnega vodnega udara ali povratnega tlaka.
Uporablja se za preprečevalnike povratnega toka s funkcijo krmiljenja z oznakami od DN 6 do DN 250.
Ta dokument zajema preprečevalnike povratnega toka PN 10, ki lahko delujejo brez spreminjanja ali prilagajanja:
– pri poljubnem tlaku do 1 MPa (10 bar);
– pri poljubnem nihanju tlaka do 1 MPa (10 bar);
– pri trajnem obratovanju pri mejni temperaturi 65 °C in največ 1 uro pri 90 °C.
Določa tudi preskusne metode in zahteve za preverjanje njihovih lastnosti, označevanje in predstavitev ob dobavi.
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN 12729:2023
01-maj-2023
Nadomešča:
SIST EN 12729:2003
Naprave za varovanje pred onesnaženjem pitne vode zaradi povratnega toka -
Sistemski ločevalnik z nadzorovanim območjem znižanega tlaka - Družina B - Tip
A
Devices to prevent pollution by backflow of potable water - Controllable backflow
preventer with reduced pressure zone - Family B - Type A
Sicherungseinrichtungen zum Schutz des Trinkwassers gegen Verschmutzung durch
Rückfließen - Systemtrenner mit kontrollierbarer druckreduzierter Zone - Familie B - Typ
A
Dispositifs de protection contre la pollution de l'eau potable - Disconnecteur à zone de
pression réduite contrôlable - Famille B - Type A
Ta slovenski standard je istoveten z: EN 12729:2023
ICS:
13.060.20 Pitna voda Drinking water
91.140.60 Sistemi za oskrbo z vodo Water supply systems
SIST EN 12729:2023 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
---------------------- Page: 1 ----------------------
SIST EN 12729:2023
---------------------- Page: 2 ----------------------
SIST EN 12729:2023
EN 12729
EUROPEAN STANDARD
NORME EUROPÉENNE
March 2023
EUROPÄISCHE NORM
ICS 13.060.20; 91.140.60 Supersedes EN 12729:2002
English Version
Devices to prevent pollution by backflow of potable water
- Controllable backflow preventer with reduced pressure
zone - Family B - Type A
Dispositifs de protection contre la pollution de l'eau Sicherungseinrichtungen zum Schutz des Trinkwassers
potable - Disconnecteur à zone de pression réduite gegen Verschmutzung durch Rückfließen -
contrôlable - Famille B - Type A Systemtrenner mit kontrollierbarer druckreduzierter
Zone - Familie B - Typ A
This European Standard was approved by CEN on 30 January 2023.
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
© 2023 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 12729:2023 E
worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
SIST EN 12729:2023
EN 12729:2023 (E)
Contents Page
European foreword . 4
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 8
4 Denomination . 9
5 Designation. 9
6 Symbolization . 10
7 Physico-chemical characteristics . 10
7.1 General . 10
7.2 Materials . 10
7.2.1 General . 10
7.2.2 Dezincification resistant copper alloy . 10
7.3 Surface coating . 11
7.3.1 General . 11
7.3.2 Epoxy coating . 11
7.3.3 Polyamide powder based coating . 11
8 Design . 11
8.1 General . 11
8.2 Relief valve . 12
9 Characteristics and tests . 13
9.1 General . 13
9.2 General tolerances . 13
9.2.1 Tolerance of set parameters . 13
9.2.2 Accuracy of measuring instruments . 13
9.3 Dimensional characteristics. 13
9.3.1 Connections . 13
9.3.2 Pressure taps . 13
9.4 Mechanical characteristics . 14
9.4.1 General . 14
9.4.2 Mechanical resistance of the body under pressure . 14
9.4.3 Endurance . 14
9.4.4 Torque test of captive rotating nuts and bending strength – tightness of the body . 16
9.4.5 Reliability of stop valves fitted to test ports . 17
9.5 Tightness characteristics . 18
9.5.1 Verification of the tightness of the downstream check valve (in the closing direction) . 18
9.5.2 Verification of the closing pressure of the downstream check valve and its tightness
(opening direction) . 18
9.5.3 Verification of the tightness of the upstream check valve at low pressure . 19
9.5.4 Verification of the tightness of the upstream check-valve under vacuum . 20
9.6 Hydraulic characteristics . 21
9.6.1 Test rig – General circuit . 21
9.6.2 Verification of the pressure loss as a function of the flow rate . 22
2
---------------------- Page: 4 ----------------------
SIST EN 12729:2023
EN 12729:2023 (E)
9.6.3 Verification of the pressure difference between the upstream and the intermediate
zones . 22
9.6.4 Verification of venting to atmospheric pressure of the intermediate zone when the
upstream pressure drops . 23
9.6.5 Verification of opening start of the relief valve and of its closing . 23
9.6.6 Verification of the relief valve tightness in case of fluctuation of the upstream
pressure . 24
9.6.7 Verification of the intermediate zone pressure for a given relief flow rate under
inverse feed . 24
9.7 Compatibility with the products used for shock disinfection of the networks . 25
9.7.1 Requirement . 25
9.7.2 Test method . 25
9.8 Acoustic tests . 25
9.8.1 General . 25
9.8.2 Procedure . 26
10 Marking and technical documents . 26
10.1 Marking . 26
10.2 Technical documents . 27
11 Presentation at delivery . 27
Annex A (normative) General information for coating definition . 28
A.1 Organic coating (paint) . 28
A.2 Pre-treatment before coating. 28
A.3 Application techniques . 28
Annex B (normative) Evaluation of the degree of polymerization . 30
B.1 Solvent resistance test . 30
Bibliography . 32
3
---------------------- Page: 5 ----------------------
SIST EN 12729:2023
EN 12729:2023 (E)
European foreword
This document (EN 12729:2023) has been prepared by Technical Committee CEN/TC 164 “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 September 2023, and conflicting national standards
shall be withdrawn at the latest by September 2023.
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 12729:2002.
The main changes compared to the previous edition are listed below:
— hydraulic and mechanical requirements have been revised;
— the Scope has been updated;
— all tests have been described in more detail and optimized;
— acoustics have been updated;
— endurance tests have been revised;
— section coatings have been added;
— solvent resistance test section has been added.
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.
4
---------------------- Page: 6 ----------------------
SIST EN 12729:2023
EN 12729:2023 (E)
Introduction
In respect of potential adverse effects on the quality of water intended for human consumption, caused
by the product covered by this document:
a) this document provides no information as to whether the product may be used without restriction
in any of the Member States of the EU or EFTA;
b) it should be noted that, while awaiting the adoption of verifiable European criteria, existing
national regulations concerning the use and/or the characteristics of this product remain in force.
5
---------------------- Page: 7 ----------------------
SIST EN 12729:2023
EN 12729:2023 (E)
1 Scope
This document specifies the field of application, the dimensional, the physico-chemical, the design, the
hydraulic, the mechanical, and the acoustic characteristics of controllable backflow preventers with
reduced pressure zone, Family B, Type A.
This document covers controllable backflow preventers of Family B, Type A, with reduced pressure
zones, intended to prevent pollution of potable water by backflow, caused by backsiphonage or by
backpressure.
It is applicable to controllable backflow preventers in denominations DN 6 up to DN 250.
It covers controllable backflow preventers of PN 10 that are capable of working without modification or
adjustment:
— at any pressure, up to 1 MPa (10 bar);
— with any pressure variation, up to 1 MPa (10 bar);
— in permanent duty at a limited temperature of 65 °C and for maximum 1 h at 90 °C.
It specifies also the test methods and requirements for verifying their characteristics, the marking and
the presentation at delivery.
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 1267, Industrial valves - Test of flow resistance using water as test fluid
EN 1329-1, Plastics piping systems for soil and waste discharge (low and high temperature) within the
building structure - Unplasticized poly(vinyl chloride) (PVC-U) - Part 1: Specifications for pipes, fittings
and the system
EN 1453-1, Plastics piping systems with structured-wall pipes for soil and waste discharge (low and high
temperature) inside buildings - Unplasticized poly(vinyl chloride) (PVC-U) - Part 1: Specifications for pipes
and the system
EN 1717, Protection against pollution of potable water in water installations and general requirements of
devices to prevent pollution by backflow
EN 10310:2003, Steel tubes and fittings for onshore and offshore pipelines - Internal and external
polyamide powder based coatings
EN 13959, Anti-pollution check valves - DN 6 to DN 250 inclusive family E, type A, B, C and D
EN 13828, Building valves - Manually operated copper alloy and stainless steel ball valves for potable
water supply in buildings - Tests and requirements
EN 14901-1, Ductile iron pipes, fittings and accessories - Requirements and test methods for organic
coatings of ductile iron fittings and accessories - Part 1: Epoxy coating (heavy duty)
6
---------------------- Page: 8 ----------------------
SIST EN 12729:2023
EN 12729:2023 (E)
EN ISO 868, Plastics and ebonite - Determination of indentation hardness by means of a durometer (Shore
hardness) (ISO 868)
EN ISO 2409, Paints and varnishes - Cross-cut test (ISO 2409)
EN ISO 2808, Paints and varnishes - Determination of film thickness (ISO 2808)
EN ISO 2812-2, Paints and varnishes - Determination of resistance to liquids - Part 2: Water immersion
method (ISO 2812-2)
EN ISO 3822-1, Acoustics - Laboratory tests on noise emission from appliances and equipment used in
water supply installations - Part 1: Method of measurement (ISO 3822-1)
EN ISO 3822-3, Acoustics - Laboratory tests on noise emission from appliances and equipment used in
water supply installations - Part 3: Mounting and operating conditions for in-line valves and appliances
(ISO 3822-3)
EN ISO 21920-2, Geometrical product specifications (GPS) - Surface texture: Profile - Part 2: Terms,
definitions and surface texture parameters (ISO 21920-2)
EN ISO 4624, Paints and varnishes - Pull-off test for adhesion (ISO 4624)
EN ISO 4628-2, Paints and varnishes - Evaluation of degradation of coatings - Designation of quantity and
size of defects, and of intensity of uniform changes in appearance - Part 2: Assessment of degree of
blistering (ISO 4628-2)
EN ISO 4628-3, Paints and varnishes - Evaluation of degradation of coatings - Designation of quantity and
size of defects, and of intensity of uniform changes in appearance - Part 3: Assessment of degree of rusting
(ISO 4628-3)
EN ISO 6272-1, Paints and varnishes - Rapid-deformation (impact resistance) tests - Part 1: Falling-weight
test, large-area indenter (ISO 6272-1)
EN ISO 8501-1, Preparation of steel substrates before application of paints and related products - Visual
assessment of surface cleanliness - Part 1: Rust grades and preparation grades of uncoated steel substrates
and of steel substrates after overall removal of previous coatings (ISO 8501-1)
EN ISO 9227, Corrosion tests in artificial atmospheres - Salt spray tests (ISO 9227)
EN ISO 11357-1, Plastics - Differential scanning calorimetry (DSC) - Part 1: General principles
(ISO 11357-1)
EN ISO 6509-1, Corrosion of metals and alloys - Determination of dezincification resistance of copper
alloys with zinc - Part 1: Test method (ISO 6509-1)
ISO 228-1, Pipe threads where pressure-tight joints are not made on the threads — Part 1: Dimensions,
tolerances and designation
7
---------------------- Page: 9 ----------------------
SIST EN 12729:2023
EN 12729:2023 (E)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 1717 and EN 806-1 and the
following apply:
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— IEC Electropedia: available at https://www.electropedia.org/
— ISO Online browsing platform: available at https://www.iso.org/obp
3.1
controllable backflow preventer with reduced pressure zone, Family B, Type A
device, called “BA”, with following specific characteristics:
— 3 pressure zones such that upstream p > intermediate p > downstream p (static no flow and
1 i 2
under water flow conditions);
— p − p > 14 kPa (140 mbar);
1 i
— connection from the intermediate pressure zone (p) to the atmosphere when p − p ≤ 14 kPa
i 1 i
(140 mbar);
— disconnection by venting the intermediate pressure zone (p ) to the atmosphere when p < 14 kPa
i 1
(140 mbar);
— a minimum set discharge flow (backflow rate);
— devices that allow verification in every zone of the disconnection and of the sealing of the
protection devices (check valves, discharge valve)
Note 1 to entry: See Figure 1.
Key
1 upstream zone p
1
2 intermediate zone p
i
3 downstream zone p
2
Figure 1 — Design principle
Note 2 to entry: For the purposes of this document, “controllable backflow preventer BA” is hereafter referred to
as “device”.
8
---------------------- Page: 10 ----------------------
SIST EN 12729:2023
EN 12729:2023 (E)
3.2
in line device
device installed within the pipework where the downstream flow of water supplies one or more points
of use
3.3
incorporated device
device integrated in appliances
EXAMPLES Cleaning apparatus, heating boilers, etc.
3.4
end of line device
device installed at the end of the pipework at the point of use for a specific purpose
EXAMPLES Temporary filling heating system, jetwasher machine, feeding points for events, etc.
4 Denomination
For the purposes of this document, for the devices the nominal size DN is a function of the minimum
flow rate given in Table 6.
5 Designation
A controllable backflow preventer with reduced pressure zone, Family B, Type A is designated by:
— its name;
— its family and its type;
— type of installation (in line, end of line or incorporated device);
— its denomination;
— its size of end connection;
— the material of its body;
— its surface finish (possible coating);
— the acoustic group I, II or nc (for DN ≤ 32);
— the reference to this document.
Examples for a designation:
— Controllable backflow preventer with reduced pressure zone — Family B — Type A, in line, DN 32,
R 11/4 × R 11/4, bronze, I, EN 12729.
— Controllable backflow preventer with reduced pressure zone — Family B — Type A, in line DN 100,
flanged, cast iron, epoxy coated, EN 12729.
9
---------------------- Page: 11 ----------------------
SIST EN 12729:2023
EN 12729:2023 (E)
6 Symbolization
The graphic representation of the controllable backflow preventer with reduced pressure zone,
Family B, Type A is as follows (see Figure 2).
Figure 2 — Graphic symbol
7 Physico-chemical characteristics
7.1 General
The selection of materials is the responsibility of the manufacturer, provided they satisfy the following
requirements:
a) materials and coatings shall not contaminate the potable water;
b) in a technical document, the manufacturer shall state the nature of the materials and coatings used;
c) materials with inadequate corrosion resistance shall have additional protection;
d) the materials used shall be suitable for the temperatures specified in the tests in this document;
e) the materials, and in particular copper alloys, for which recommendations or international
standards exist, shall comply with the relevant European standards.
7.2 Materials
7.2.1 General
All materials coming into contact with water intended for human consumption shall present no health
risk nor cause any change to the water in terms of quality, appearance, smell or taste.
NOTE While awaiting the adoption of verifiable European criteria for testing materials in contact with water
intended for human consumption, existing national regulations concerning the use and/or the characteristics of
these products remain in force.
7.2.2 Dezincification resistant copper alloy
Copper-zinc alloys containing more than 15 % zinc are subject to dezincification when submitted to
water capable of dezincification. In the countries where the use of products made of dezincification
resistant materials is required, the materials used shall guarantee a dezincification depth less than
200 μm in any direction. For this purpose, materials shall be tested in accordance with EN ISO 6509-1
and the product shall be marked in compliance with the indications according to Clause 11.
10
---------------------- Page: 12 ----------------------
SIST EN 12729:2023
EN 12729:2023 (E)
7.3 Surface coating
7.3.1 General
The outside and inside surfaces of the device may contain a coating. Such coating shall not impair the
functional characteristics of the device.
The coating for protection of the basic material against corrosion can be either realized by epoxy
coating or by polyamide powder-based coating. See also Table A.1.
7.3.2 Epoxy coating
Epoxy coating shall fulfil the requirements as described in Annex A based on EN 14901-1.
7.3.3 Polyamide powder based coating
Polyamide powder coating shall fulfil the requirements as described in Annex A based on
EN 10310:2003.
8 Design
8.1 General
a) The internal components of the device shall be accessible for inspection, repair or replacement.
These operations shall be possible on the installed device. Mandatory maintenance can also be
done by removing the device from the pipework for sizes DN ≤ 20. By design, the components shall
be able to be refitted at their initial place, without ambiguity (impossibility of reversal, interchange
of obturators, diaphragms, springs …). A visible mark is not sufficient;
b) the settings of the springs shall be fixed and not adjustable;
c) in line devices and incorporated devices shall comprise three pressure tapings, upstream,
intermediate, downstream, permitting periodic verification of the function of the device;
d) end of line devices shall comprise at least two pressure tapings, upstream and intermediate
permitting periodic verification of the function of the device.
They are placed:
— upstream of the first check valve;
— in the intermediate zone;
e) It shall be possible to vent the air which can accumulate inside the device;
f) the internal components of the device can only be controlled by the pressure of the water of the
supply network;
g) possible additional control devices (electric, pneumatic, …) shall not adversely affect the backflow
protection function;
h) normally the device shall be installed horizontally. Devices DN ≤ 50 may be installed in the
downward vertical orientation in accordance with the design of the valve and the manufacturers’
instructions while satisfying all the criteria in this document. If this orientation influences the
function of the devices the tests shall be carried out in all possible orientations.
11
---------------------- Page: 13 ----------------------
SIST EN 12729:2023
EN 12729:2023 (E)
8.2 Relief valve
The design of the relief valve operation shall be such that when the differential pressure over the
upstream check valve is less than 14 kPa (140 mbar) the relief valve shall be open to ensure safety.
An internal vertical distance h, as shown in the Figure 3 (in disconnected position) shall be provided
between the upstream check valve seat and the seat of relief valve:
— h ≥ 5 mm for DN ≤ 15;
— h ≥ 10 mm for 15 < DN ≤ 50;
— h ≥ 20 mm for DN > 50.
Figure 3 — Relief orifice
In none of the installation positions indicated by the manufacturer, any water retention with the
intermediate zone shall be possible.
The cross sections of the passage orifices and of the pilot tube for operation of the relief device shall be
2 2
greater than or equal to 45 mm with DN ≥ 15, or 12,5 mm with DN < 15. No dimension for the
calculation of the cros
...
SLOVENSKI STANDARD
oSIST prEN 12729:2020
01-september-2020
Naprave za varovanje pred onesnaženjem pitne vode zaradi povratnega toka -
Sistemski ločevalnik z nadzorovanim območjem znižanega tlaka - Družina B - Tip A
Devices to prevent pollution by backflow of potable water - Controllable backflow
preventer with reduced pressure zone - Family B - Type A
Sicherungseinrichtungen zum Schutz des Trinkwassers gegen Verschmutzung durch
Rückfließen - Systemtrenner mit kontrollierbarer druckreduzierter Zone - Familie B - Typ
A
Dispositifs de protection contre la pollution de l'eau potable - Disconnecteur à zone de
pression réduite contrôlable - Famille B - Type A
Ta slovenski standard je istoveten z: prEN 12729
ICS:
13.060.20 Pitna voda Drinking water
91.140.60 Sistemi za oskrbo z vodo Water supply systems
oSIST prEN 12729:2020 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
---------------------- Page: 1 ----------------------
oSIST prEN 12729:2020
---------------------- Page: 2 ----------------------
oSIST prEN 12729:2020
DRAFT
EUROPEAN STANDARD
prEN 12729
NORME EUROPÉENNE
EUROPÄISCHE NORM
July 2020
ICS 13.060.20; 91.140.60 Will supersede EN 12729:2002
English Version
Devices to prevent pollution by backflow of potable water
- Controllable backflow preventer with reduced pressure
zone - Family B - Type A
Dispositifs de protection contre la pollution de l'eau Sicherungseinrichtungen zum Schutz des Trinkwassers
potable - Disconnecteur à zone de pression réduite gegen Verschmutzung durch Rückfließen -
contrôlable - Famille B - Type A Systemtrenner mit kontrollierbarer druckreduzierter
Zone - Familie B - Typ A
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 164.
If this draft becomes a European Standard, 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.
This draft European Standard was established by CEN 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, Turkey and
United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.
Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 12729:2020 E
worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
oSIST prEN 12729:2020
prEN 12729:2020 (E)
Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 6
4 Denomination. 7
5 Designation . 7
6 Symbolization . 8
7 Physico-chemical characteristics . 8
7.1 General. 8
7.2 Materials . 8
7.3 Surface coating . 8
8 Design . 9
8.1 General. 9
8.2 Relief valve . 9
9 Characteristics and tests . 10
9.1 General. 10
9.2 General tolerances . 10
9.3 Dimensional characteristics . 11
9.4 Mechanical characteristics . 12
9.5 Tightness characteristics . 16
9.6 Hydraulic characteristics . 19
9.7 Compatibility with the products used for shock disinfection of the networks . 23
9.8 Acoustic tests . 24
10 Marking and technical documents . 24
10.1 Marking . 24
10.2 Technical documents . 25
11 Presentation at delivery . 26
Annex A (normative) General Information for Coating . 27
Bibliography . 29
2
---------------------- Page: 4 ----------------------
oSIST prEN 12729:2020
prEN 12729:2020 (E)
European foreword
This document (prEN 12729:2020) has been prepared by Technical Committee CEN/TC 164 “Water
supply”, the secretariat of which is held by AFNOR.
This document is currently submitted to the CEN Enquiry.
This document will supersede EN 12729:2002.
3
---------------------- Page: 5 ----------------------
oSIST prEN 12729:2020
prEN 12729:2020 (E)
Introduction
In respect of potential adverse effects on the quality of water intended for human consumption, caused
by the product covered by this document:
a) this document provides no information as to whether the product may be used without restriction
in any of the Member States of the EU or EFTA;
b) it should be noted that, while awaiting the adoption of verifiable European criteria, existing
national regulations concerning the use and/or the characteristics of this product remain in force.
4
---------------------- Page: 6 ----------------------
oSIST prEN 12729:2020
prEN 12729:2020 (E)
1 Scope
This document specifies the field of application, the dimensional, the physico-chemical, the design, the
hydraulic, the mechanical, and the acoustic characteristics of controllable backflow preventers with
reduced pressure zone Family B Type A.
This document covers controllable backflow preventers of Family B Type A, with reduced pressure
zones, intended to prevent pollution of potable water by backflow, caused by backsiphonage or by
backpressure.
It is applicable to controllable backflow preventers in denominations DN 6 up to DN 250.
It covers controllable backflow preventers of PN 10 that are capable of working without modification or
adjustment:
— at any pressure, up to 1 MPa (10 bar);
— with any pressure variation, up to 1 MPa (10 bar);
— in permanent duty at a limited temperature of 65 °C and for maximum 1 h at 90 °C.
It specifies also the test methods and requirements for verifying their characteristics, the marking and
the presentation at delivery.
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 1717, Protection against pollution of potable water in water installations and general requirements of
devices to prevent pollution by backflow
EN 10310:2003, Steel tubes and fittings for onshore and offshore pipelines — Internal and external
polyamide powder based coatings
EN 13828, Building valves — Manually operated copper alloy and stainless steel ball valves for potable
water supply in buildings — Tests and requirements
EN 14901, Ductile iron pipes, fittings and accessories — Epoxy coating (heavy duty) of ductile iron fittings
and accessories — Requirements and test methods
EN ISO 3822-1, Acoustics — Laboratory tests on noise emission from appliances and equipment used in
water supply installations — Part 1: Method of measurement (ISO 3822-1)
EN ISO 3822-3:2018, Acoustics — Laboratory tests on noise emission from appliances and equipment used
in water supply installations — Part 3: Mounting and operating conditions for in-line valves and
appliances (ISO 3822-3:2018)
EN ISO 6509-1, Corrosion of metals and alloys — Determination of dezincification resistance of copper
alloys with zinc — Part 1: Test method (ISO 6509-1)
5
---------------------- Page: 7 ----------------------
oSIST prEN 12729:2020
prEN 12729:2020 (E)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 1717 and EN 806-1 and the
following apply:
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
3.1
controllable backflow preventer with reduced pressure zone-Family B-Type A
specific characteristics of this device called “BA”, are as follows:
• 3 pressure zones such that upstream p > intermediate p > downstream p (static no flow and under
1 i 2
water flow conditions);
• p − p > 14 kPa (140 mbar);
1 i
• connection from the intermediate pressure zone (p) to the atmosphere when p − p ≤ 14 kPa
i 1 i
(140 mbar);
• disconnection by venting the intermediate pressure zone (p ) to the atmosphere when p < 14 kPa
i 1
(140 mbar);
• a minimum set discharge flow (backflow rate);
• devices that allow verification in every zone of the disconnection and of the sealing of the protection
devices (check valves, discharge valve)
Note 1 to entry: see Figure 1
Key
1 upstream zone p
1
2 intermediate zone p
i
3 downstream zone p2
Figure 1 — Design principle
Note 2 to entry: For the purpose of this document, “controllable backflow preventer BA” is hereafter referred to
as “device”
6
---------------------- Page: 8 ----------------------
oSIST prEN 12729:2020
prEN 12729:2020 (E)
3.2
in line device
installed within the pipework where the downstream flow of water supplies one or more points of use
3.3
incorporated device
integrated in appliances e.g. cleaning apparatus, heating boilers
3.4
end of line device
installed at the end of the pipework at the point of use for a specific purpose e.g. filling heating system,
jetwasher machine, …
4 Denomination
For the purpose of this document for the devices the nominal size DN is a function of the minimum flow
rate given in Table 6.
5 Designation
A controllable backflow preventer with reduced pressure zone-Family B-Type A is designated by:
• its name;
• its family and its type;
• type of installation (in line, end of line or incorporated device);
• its denomination;
• its size of end connection;
• the material of its body;
• its surface finish (possible coating);
• the acoustic group I, II or nc (for DN ≤ 32);
• the reference to the present standard.
Examples for a designation:
Controllable backflow preventer with reduced pressure zone — Family B — Type A, in line, DN 32,
R 11/4 × R 11/4, bronze, I, EN 12729.
Controllable backflow preventer with reduced pressure zone — Family B — Type A, in line DN 100,
flanged, cast iron, epoxy coated, EN 12729.
7
---------------------- Page: 9 ----------------------
oSIST prEN 12729:2020
prEN 12729:2020 (E)
6 Symbolization
The graphic representation of the controllable backflow preventer with reduced pressure zone-
Family B-Type A is as follows (see Figure 2):
Figure 2 — Graphic symbol
7 Physico-chemical characteristics
7.1 General
The selection of materials is the responsibility of the manufacturer, provided they satisfy the following
requirements:
a) materials and coatings shall not contaminate the potable water;
b) in a technical document, the manufacturer shall state the nature of the materials and coatings used;
c) materials with inadequate corrosion resistance shall have additional protection;
d) the materials used shall be suitable for the temperatures specified in the tests in this document;
e) the materials, and in particular copper alloys, for which recommendations or international
standards exist, shall comply with the relevant European standards.
7.2 Materials
All materials in accordance with national regulations of the European Community and/or European
standards may be used.
Copper-zinc alloys containing more than 10 % zinc are subject to dezincification when submitted to
water capable of dezincification. In the countries where the use of products made of dezincification
resistant materials is required, the materials used shall guarantee a dezincification depth less than
200 µm in any direction. For this purpose, materials shall be tested in accordance with EN ISO 6509-1
and the product shall be marked in compliance with the indications according to Clause 10.
7.3 Surface coating
7.3.1 General
The outside and inside surfaces of the device may or may not contain a coating. Such coating shall not
impair the functional characteristics of the device.
The coating for protection of the basic material against corrosion can be either realized by epoxy
coating or by polyamide powder based coating.
7.3.2 Epoxy Coating
Epoxy coating shall fulfill the requirements as described in Annex A based on EN 14901.
8
---------------------- Page: 10 ----------------------
oSIST prEN 12729:2020
prEN 12729:2020 (E)
7.3.3 Polyamide Powder based Coating
Polyamide powder coating shall fulfill the requirements as described in Annex A based on EN 10310.
8 Design
8.1 General
a) The internal components of the device shall be accessible for inspection, repair or replacement.
These operations shall be possible on the installed device. Mandatory maintenance can also be
done by removing the device from the pipework for sizes DN ≤ 20. By design, the components shall
be able to be refitted at their initial place, without ambiguity (impossibility of reversal, interchange
of obturators, diaphragms, springs …). A visible mark is not sufficient;
b) the settings of the springs shall be fixed and not adjustable;
c) in line devices and incorporated devices shall comprise three pressure tappings, upstream,
intermediate, downstream, permitting periodic verification of the function of the device;
d) end of line devices shall comprise at least two pressure tappings, upstream and intermediate
permitting periodic verification of the function of the device.
They are placed:
• upstream of the first check valve;
• in the intermediate zone;
It shall be possible to vent the air which can accumulate inside the device at the highest point of the
device;
e) only the pressure of the water of the supply network can operate the control of the internal
components of the device;
f) possible additional control devices (electric, pneumatic, …) shall not adversely affect the backflow
protection function;
g) normally the device shall be installed horizontally. Devices DN ≤ 50 may, be installed in the
downward vertical orientation in accordance with the design of the valve and the manufacturers’
instructions while satisfying all the criteria in this document. If this orientation influences the
function of the devices the tests shall be carried out in all possible orientations.
8.2 Relief valve
The design of the relief valve operation shall be such that when the differential pressure over the
upstream check valve is less than 14 kPa (140 mbar) the relief valve shall be open to ensure positive
safety.
An internal vertical distance h, as shown in the figure x and y (in disconnected position) shall be
provided between the upstream check valve seat and the seat of relief valve:
• h ≥ 5 mm for DN ≤ 15;
• h ≥ 10 mm for 15 < DN ≤ 50;
9
---------------------- Page: 11 ----------------------
oSIST prEN 12729:2020
prEN 12729:2020 (E)
• h ≥ 20 mm for DN > 50.
In all the installation positions indicated by the manufacturer, any water retention shall not be possible
within the intermediate zone.
The cross sections of the passage orifices and of the pilot tube for operation of the relief device shall be
2 2
equal to or greater than 45 mm with DN ≥ 15, or 12,5 mm with DN < 15. No dimension for the
calculation of the cross section shall be less than 4 mm. The outside pilot tube shall be made so as not to
be subject to any permanent deformation or rupture under outside stresses.
An air break to drain shall exist between any waste drain and any means of collecting the discharged
water (floor, tundish, curb, sink).
The air break to drain shall meet the dimensional requirements as specified in EN 1717. This air break
to drain shall be:
• either directly incorporated into the device;
• or factory fitted;
• or supplied with the device,
• or guaranteed by the installation.
In the latter case, the relief orifice of the device shall permit, neither the fitting of a standardized
threaded pipe, nor the connection of a standardized pipe or shape, be it by glue, welding or interlocking.
If applicable on the dimension ‘’G” of the outlet of the air break to drain (see in EN 1717), it shall be
possible to fit a standardized drain pipe (Standard EN 1329-1 PVC compact and EN 1453-1 PVC with
structured walls).
9 Characteristics and tests
9.1 General
Performance tests shall be carried out on the device as installed in accordance with the manufacturer’s
technical documents, subject to dimension h being complied with.
If not specified, all tests shall be performed with water at an ambient temperature.
9.2 General tolerances
9.2.1 Tolerance of set parameters
In the absence of any particular specifications:
• flow rate and pressure: ± 2 % of the value specified;
• temperature:cold water: ± 5 °C of the value specified;
hot water: ± 2 °C of the value specified;
other values: ± 2 °C of the value specified;
10 %
• time of the value specified.
0
10
---------------------- Page: 12 ----------------------
oSIST prEN 12729:2020
prEN 12729:2020 (E)
9.2.2 Accuracy of measuring instruments
All the measuring instruments shall have an error limit of ± 2 % of the measured value.
9.3 Dimensional characteristics
9.3.1 Connections
The connection shall be in accordance with the relevant European Standards.
9.3.2 Pressure taps
The devices shall have one test port orifice per zone according to the indications as shown in Figure 3
and Table 1.
2
The bores for pressure taps shall have over their full length a minimum cross-section of 12,56 mm .
Their smallest dimension shall be not less than 4 mm.
The outlet of isolating valve shall be in accordance to the indications as shown in Figure 3 and Table 1.
Table 1 — Dimension of thread and test parts
DN Thread a
(designation in accordance with ISO 228-1) mm
≤ 15 G 1/8 or G 1/4 > 6,5
20 ≤ DN ≤ 50 G 1/4 > 6,5
> 50 G 1/2 > 13
Key
G Thread
a Test part
Figure 3 — Pressure tap orifice
These test ports shall be fitted with stop valves or other technical means for the verification of the
device e.g. fast couplings, removable plugs, …
If stop valves are fitted, they shall be in accordance with the following requirements:
• For devices DN ≤ 15 G 1/8 or G 1/4 connection female outlet;
• For device 20 ≤ DN ≤ 50 G 1/4 connection female outlet;
• For device DN > 50 G 1/2 connection female outlet.
11
---------------------- Page: 13 ----------------------
oSIST prEN 12729:2020
prEN 12729:2020 (E)
9.4 Mechanical characteristics
9.4.1 General
Examples shown in the figures are for guidance only. Laboratory equipment shall be designed to ensure
that the device can be tested in accordance with the requirement.
9.4.2 Mechanical resistance of the body under pressure
9.4.2.1 Requirement
There shall be no visual permanent deformation or rupture of the body or the internal parts of the
device.
9.4.2.2 Test method
Apply at the inlet of the device in increments of 0,1 MPa (1 bar) per 5 s an increase of the static water
pressure up to 2,5 times the PN, the value that equals 2,5 MPa (25 bar); hold this pressure for 5 min.
Observe the device and note any observations.
Verify that the device satisfies the requirement of 9.5.1.1.
9.4.3 Endurance
9.4.3.1 Requirement
a) The endurance test shall be done with the same sample that has been tested according to 9.6.1,
9.6.2, 9.6.3, 9.7.4 and 9.8. After performing the test according to 9.4.4.2 the sample shall fulfill the
requirements according to 9.6.1, 9.6.2, 9.6.3, 9.7.4 and 9.6.4;
b) There shall be no visible damages or deformation of the coating, and of components.
9.4.3.2 Tests
Test 1 — Behaviour at temperature.
Place the complete device for 72 h in an environment at a temperature of 65 °C, and at a relative
humidity of 50 ± 10 %.
Test 2 — Thermal shock.
Following the preceding test, put the complete device at the flow rate as given in the Table 4, supplying
it with water at 90 °C.
Once temperature reaches 85 °C at the outlet of the device, hold the flow rate for 60 min, and then
supply for 10 min with water at 15 °C.
12
---------------------- Page: 14 ----------------------
oSIST prEN 12729:2020
prEN 12729:2020 (E)
Test 3 — Mechanical endurance.
A Supply flow; maximum pressure of 0,3 MPa (3 bar) at zero flow
B Supply pressure: (1 ± 0,05) MPa (10 bar ± 0,5 bar)
C Supply pressure: (0,3 ± 0,03) MPa (3 bar ± 0,3 bar)
Key
valve with time control of opening and closing
adjusting valve
6 pressure gauge
Figure 4 — Endurance testing equipment
Following the preceding tests 1 and 2, submit the device placed in the testing equipment (see Figure 4)
+50
to 5 000 cycles at a temperature of 65 °C, each cycle comprising:
0
• Stage 1: Open valve 5 then valve 1, circulation at a flow rate as given in Table 2 at the value ± 5 %
for (6 ± 2) s;
• Stage 2: Close valve 5 then valve 1;
• Stage 3: Open valve 3, static pressure at 0,3 MPa (3 bar) for (6 ± 2) s;
• Stage 4: Close valve 3, open valve 4. Upstream drain for (6 ± 2) s (opening of the relief valve);
• Stage 5: Close valve 4;
• Stage 6: Open valve 5 then valve 1, circulation at a flow rate as given in Table 2 at the value ± 5 %
for (6 ± 2) s;
• Stage 7: Close valve 5 then valve 1;
• Stage 8: Open valve 2. Static pressure at 1 MPa (10 bar) for (6 ± 2) s;
• Stage 9: Close valve 2, open valve 4. Upstream drain (opening of the relief valve) for (6 ± 2) s;
13
---------------------- Page: 15 ----------------------
oSIST prEN 12729:2020
prEN 12729:2020 (E)
• Stage 10: Close valve 4.
The 5 000 cycles are broken down into seven periods as follows:
• 1 250 cycles;
• the device is at rest for 14 hours at ambient temperature;
• 1 250 cycles;
• the device is maintained under load at a static pressure of 1 MPa (10 bar) for 14 h at ambient
temperature;
• 1 250 cycles;
• the device is submitted for 14 h to an upstream pressure of 0,3 MPa (3 bar) and to a downstream
pressure of 1 MPa (10 bar) at ambient temperature;
• 1 250 cycles.
Table 2 — Nominal size versus endurance test flow rate
DN 6 8 10 15 20 25 32 40
3
Flow rate m /h 0,25 0,4 0,6 1,3 2,2 3,5 5,8 9
DN 50 65 80 100 125 150 200 250
3
Flow rate m /h 14 24 36 56 56 56 56 56
Perform test according to 9.6.1, 9.6.2, 9.6.3, 9.7.4 and 9.6.4 in the indicated sequence.
9.4.4 Torque test of Captive rotating Nuts and Bending Strength – Tightness of the Body
9.4.4.1 Requirement
a) After unscrewing, no visual damage of the nut shall be detected.
b) There shall be no rupture nor permanent deformation or leakage on the body of the device. The test
shall be carried out under the conditions defined in 9.4.4.2.
9.4.4.2 Test method
The device shall be fixed to the test rig, into operating orientation, as shown in Figure 5, swivel nut
connection shall be tightened with the torque specified in Table 3. Gradually apply torque to the captive
rotating nut/backnut until the tightening torque is reached and maintain it for a period of at least 1 min.
Once it is in water under pressure and without bending stress, the fitting shall be leaktight. In case it is
not leaktight, the tightening torque can be increased.
Apply a load W as shown in Figure 5 corresponding to the bending moment shown in Table 4 according
to the type of product (see 3.2, 3.3 and 3.4). Apply pressure up to 1,6 MPa (16 bar) with increments of
0,1 MPa (1 bar) per 5 s.
Maintain bending moment and pressure for 10 min. When calculating load W corresponding to the
bending moment, loads introduced by the piping and taps and any loads coming from the test apparatus
shall be accounted for.
14
---------------------- Page: 16 ----------------------
oSIST prEN 12729:2020
prEN 12729:2020 (E)
Table 3 — Torsional strength
Nominal size DN 10 15 20 25 32 40 50
Tightening torque (Nm) 30 60 75 100 125 150 150
Key
W load
1 isolating valve
2 pressure gauge
Figure 5 — Bending moment testing equipment
Table 4 — Nominal size versus bending moment
N 6 8 10 15 20 25 32 40
In line device 20 30 40 70 110 150 250 300
Bending
moment
End of line device 30 50 70 120 190 220
Nm
Incorporated device Not applicable
DN 50 65 80 100 125 150 200 250
In line device 500 750 950 1 300 1 800 2 400 3 800 5 500
Bending
moment
End of line device 300
Nm
Incorporated device Not applicable
Verify that the device satisfies the requirements of 9.4.4.1.
9.4.5 Reliability of isolation valves fitted to test ports (if applicable)
9.4.5.1 General
The following test shall only be performed if the isolating valves are not in accordance with the
requirements of EN 13828.
The isolation valves fitted to the pressure taps shall be easily manoeuvrable.
The isolation valves of flanged devices shall be operable by hand without additional tools.
The opening and closing positions shall be defined by mechanical stops.
15
---------------------- Page: 17 ----------------------
oSIST prEN 12729:2020
prEN 12729:2020 (E)
9.4.5.2 Operating torque
9.4.5.2.1 General
Before starting the test, one preliminary cycle shall be carried out. The valve shall then be left for 24 h at
ambient temperature.
The operating torque of the valve is measured
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.