EN 12729:2002

SLOVENSKI STANDARD
01-oktober-2003
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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 par retour de l'eau potable - Disconnecteur a
zone de pression réduite contrôlable - Famille B - Type A
Ta slovenski standard je istoveten z: EN 12729:2002
ICS:
13.060.20 Pitna voda Drinking water
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.

EUROPEAN STANDARD
EN 12729
NORME EUROPÉENNE
EUROPÄISCHE NORM
November 2002
ICS 13.060.20; 91.140.60
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 par retour de Sicherungseinrichtungen zum Schutz des Trinkwassers
l'eau potable - Disconnecteur à zone de pression réduite gegen Verschmutzung durch Rückfließen - Systemtrenner
contrôlable - Famille B - Type A mit kontrollierbarer druckreduzierter Zone - Familie B - Typ
A
This European Standard was approved by CEN on 7 September 2002.
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 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 Management Centre has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,
Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2002 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 12729:2002 E
worldwide for CEN national Members.

Contents
page
Foreword.3
Introduction .4
1 Scope .5
2 Normative references .5
3 Terms and definitions.6
4 Denomination .7
5 Designation.7
6 Symbolization.7
7 Physico-chemical characteristics .8
7.1 Materials.8
7.2 Nature of the materials .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 Expression of the results.10
9.4 Dimensional characteristics .10
9.5 Mechanical characteristics .11
9.6 Tightness characteristics.15
9.7 Hydraulic characteristics .18
10 Order of testing .23
11 Marking and technical documents.24
11.1 Marking .24
11.2 Technical documents .24
12 Presentation at delivery .25
Annex A (informative)  Examples of presentation of test results.26
Bibliography .32
Foreword
This document (EN 12729:2002) 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 May 2003, and conflicting national standards shall be withdrawn at the latest by
May 2003.
The annex A is informative.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland,
France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain,
Sweden, Switzerland 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 standard:
a) this standard 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.
1 Scope
This European Standard specifies the field of application, the dimensional, the physico-chemical, the design, the
hydraulic, the mechanical, and the acoustic characteristics of controllable backflow preventer with reduced
pressure zone Family B Type A.
This standard covers controllable backflow preventers of Family B Type A, with reduced pressure zones, intended
to prevent backflow by backsiphoning or backpressure of water into the potable water distribution system whenever
the pressure of the latter is lower than the system located downstream.
It is applicable to controllable backflow preventers in denominations DN 8 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 90 °C for 1 h maximum.
It specifies also the test methods and requirements for verifying their characteristics, the marking and the
presentation at delivery.
2 Normative references
This European Standard incorporates by dated or undated reference, provisions from other publications. These
normative references are cited at the appropriate places in the text, and the publications are listed hereafter. For
dated references, subsequent amendments to or revisions of any of these publications apply to this European
Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the
publication referred to applies (including amendments).
EN 806-1:2000, Specifications for installations inside buildings conveying water for human consumption - Part 1:
General.
EN 1092-1, Flanges and their joints – Circular flanges for pipes, valves, fittings and accessories, PN designated –
Part 1: Steel flanges.
EN 1092-2, Flanges and their joints – Circular flanges for pipes, valves, fittings and accessories, PN designated –
Part 2: Cast iron flanges.
EN 1717:2000, Protection against pollution of potable water in water installations and general requirements of
devices to prevent pollution by backflow.
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 3822-1:1999).
EN ISO 3822-3:1997, 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 3822-3:1997).
EN ISO 6509, Corrosion of metals and alloys - Determination of dezincification resistance of brass (ISO
6509:1981).
prEN 13959, Anti-pollution check valves DN 6 to DN 250 inclusive-Family E-Type A, B, C and D.
ISO 7-1, Pipe threads where pressure-tight joints are made on the threads - Part 1: Dimensions, tolerances and
designation.
ISO 228-1, Pipe threads where pressure-tight joints are not made on the threads - Part 1: Dimensions, tolerances
and designation.
ISO 9227, Corrosion tests in artificial atmosphere - Salt spray tests.
3 Terms and definitions
For the purposes of this European Standard, the terms and definitions of EN 1717 and EN 806-1 together with the
following apply.
3.1
controllable backflow preventer with reduced pressure zone-Family B-Type A
the specific characteristics of this device called “BA”, (see Figure 1) are as follows:
3 pressure zones such that upstream p > intermediate p > downstream p (static no flow and under water flow
1 i 2
conditions);
p - p > 14 kPa (140 mbar);
1 i
connection from the intermediate pressure zone (p ) to the atmosphere when p - p £ 14 kPa (140 mbar);
i 1 i
disconnection by venting the intermediate pressure zone (p ) to the atmosphere when p shall be up to 14 kPa
i 1
(140 mbar);
a minimum set discharge flow (backflow rate);
devices that allow verification in every zone of the disconnection and the sealing of the protection devices
(obturators, discharge valves).
Key
1 Upstream zone p
2 Intermediate zone p
i
3 Downstream zone p
Figure 1 — Design principle
For the purposes of this standard «controllable backflow preventer BA» is hereafter referred to as «device».
4 Denomination
The denomination of the device is given in Table 1:
Table 1 — DN versus threads and flanges
Denomination DN 8 101520 253240
Threads 1/4 3/8 1/2 3/4 1 1 1
(designation in accordance 1/4 1/2
with ISO 7-1)
Flanges (DN) 40
Denomination DN 50 65 80 100 125 150 200 250
Threads 2
(designation in accordance
with ISO 7-1)
Flanges (DN) 50 65 80 100 125 150 200 250
NOTE For specifications of threads and flanges see 9.4.
5 Designation
A controllable backflow preventer with reduced pressure zone-Family B-Type A is designated by:
its name;
its family and its type;
its denomination (see Table 1);
its connection type;
the material of its body;
its surface finish (possible coating);
the acoustic group (for DN £ 32);
the reference to the present standard.
Examples for a designation:
Controllable backflow preventer with reduced pressure zone - Family B - Type A, DN 32, G 1"1/4 x G 1"1/4,
bronze, I, EN 12729.
Controllable backflow preventer with reduced pressure zone - Family B - Type A, DN100, flanged, cast iron, epoxy
coated, EN 12729.
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 Materials
The materials and the coatings used, liable to come normally or accidentally in contact with potable water, shall
satisfy the EU regulation
...