Building valves - Expansion groups - Tests and requirements

The document specifies, dimensions, materials and performance requirements (including methods of test) for expansion groups, of nominal sizes from DN 15 to DN 25, having working pressures ) from 0,1 MPa (1 bar) to 1,0 MPa (10 bar).
Expansion groups shall be fitted to the cold potable water supply only for expansion purposes, e.g. of storage water heaters, having a maximum distribution temperature of 95 °C.
Expansion groups limit pressure in the water heater to which they are fitted, that is produced by thermal expansion of the water, prevent the backflow of water into the supply pipe and prevent the discharged water to get into contact with the water in the water heater.
Expansion groups do not control temperature and alone do not constitute the protection required for storage water heaters.
NOTE   The use of the device specified in this Standard does not override the need to use controls (e.g. thermostats and thermal cut-outs) which act directly on the power sources of water heaters.

Gebäudearmaturen - Sicherheitsgruppen für Expansionswasser - Prüfungen und Anforderungen

Dieses Dokument legt Abmessungen, Werkstoffe und Leistungsanforderungen (einschließlich Prüfverfahren) für Sicherheitsgruppen für Expansionswasser mit einer Nennweite von DN 15 bis DN 25 und Betriebsdrücken ) von 0,1 MPa (1 bar) bis 1,0 MPa (10 bar) fest.
Sicherheitsgruppen für Expansionswasser müssen ausschließlich zu Expansionszwecken an die Kaltwasserversorgung angeschlossen werden, z. B. an Speicher-Warmwasserbereiter mit einer höchsten Verteilungstemperatur von 95 °C.
Sicherheitsgruppen für Expansionswasser begrenzen den, durch die thermische Ausdehnung des Wassers entstehenden, Druck im Warmwasserbereiter, an den sie angeschlossen sind, verhindern den Rückfluss von Wasser und die Versorgungsleitung und verhindern, dass abgeleitetes Wasser in Kontakt mit dem Wasser im Warmwasserbereiter kommt.
Sicherheitsgruppen für Expansionswasser steuern weder die Temperatur, noch stellen Sie allein einen für Speicher-Warmwasserbereiter nötigen Schutz dar.
ANMERKUNG   Durch die Verwendung des in diesem Dokument beschriebenen Gerätes wird die Notwendigkeit zu Verwendung von Steuereinrichtungen (z. B. Thermostate und Thermoauslöser), die direkt an den Leistungsquellen von Warmwasserbereitern zum Einsatz kommen, nicht aufgehoben.

Robinetterie de bâtiment - Groupes d'expansion - Essais et exigences

Le présent document spécifie les dimensions, les matériaux et les exigences de performance (y compris les méthodes d’essai) pour les groupes d’expansion de dimensions nominales allant de DN 15 à DN 25 et dont la pression de service  ) va de 0,1 MPa (1 bar) à 1,0 MPa (10 bar).
Les groupes d’expansion ne doivent être raccordés à l’alimentation en eau potable froide que pour des besoins d’expansion, par exemple de chauffe-eau à accumulation ayant une température maximale de distribution de 95 °C.
Les groupes d’expansion permettent de limiter l’augmentation de la pression du fluide contenu dans le chauffe-eau, qui est générée par la dilatation de l’eau, ils empêchent le retour de l’eau dans la canalisation d’alimentation et tout contact entre l’eau du réseau d’évacuation et l’eau du chauffe-eau.
Les groupes d’expansion ne contrôlent pas la température et n’assurent pas à eux seuls la protection nécessaire des chauffe-eau à accumulation.
NOTE   L’usage du dispositif spécifié dans le présent document ne dispense pas de la nécessité d’utiliser des commandes (par exemple, thermostats et dispositifs de coupure) qui agissent directement sur les sources d’énergie des chauffe-eau.

Ventili v stavbah - Ekspanzijski bloki - Preskusi in zahteve

General Information

Status
Published
Public Enquiry End Date
14-Jun-2020
Publication Date
17-Jun-2021
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
14-Jun-2021
Due Date
19-Aug-2021
Completion Date
18-Jun-2021

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SLOVENSKI STANDARD
SIST EN 1488:2021
01-september-2021
Nadomešča:
SIST EN 1488:2000
Ventili v stavbah - Ekspanzijski bloki - Preskusi in zahteve
Building valves - Expansion groups - Tests and requirements
Gebäudearmaturen - Sicherheitsgruppen für Expansionswasser - Prüfungen und
Anforderungen
Robinetterie de bâtiment - Groupes d'expansion - Essais et exigences
Ta slovenski standard je istoveten z: EN 1488:2021
ICS:
23.060.01 Ventili na splošno Valves in general
91.140.60 Sistemi za oskrbo z vodo Water supply systems
SIST EN 1488:2021 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
SIST EN 1488:2021
---------------------- Page: 2 ----------------------
SIST EN 1488:2021
EN 1488
EUROPEAN STANDARD
NORME EUROPÉENNE
May 2021
EUROPÄISCHE NORM
ICS 91.140.60 Supersedes EN 1488:2000
English Version
Building valves - Expansion groups - Tests and
requirements

Robinetterie de bâtiment - Groupes d'expansion - Gebäudearmaturen - Sicherheitsgruppen für

Essais et exigences Expansionswasser - Prüfungen und Anforderungen
This European Standard was approved by CEN on 19 March 2021.

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, Turkey 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

© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 1488:2021 E

worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
SIST EN 1488:2021
EN 1488:2021 (E)
Contents Page

European foreword ....................................................................................................................................................... 4

Introduction .................................................................................................................................................................... 5

1 Scope .................................................................................................................................................................... 6

2 Normative references .................................................................................................................................... 6

3 Terms and definitions ................................................................................................................................... 7

4 Materials and surface finishes .................................................................................................................... 9

4.1 General ................................................................................................................................................................ 9

4.2 Materials .......................................................................................................................................................... 10

4.3 Detection of residual stress ...................................................................................................................... 10

4.3.1 General ............................................................................................................................................................. 10

4.3.2 Test .................................................................................................................................................................... 10

4.3.3 Test method (Procedure) .......................................................................................................................... 10

4.3.4 Requirements ................................................................................................................................................ 11

4.4 Corrosion resistance test ........................................................................................................................... 11

4.4.1 General ............................................................................................................................................................. 11

4.4.2 Test method ................................................................................................................................................... 11

4.4.3 Requirements ................................................................................................................................................ 11

4.5 Coating adherence test ............................................................................................................................... 12

4.5.1 General ............................................................................................................................................................. 12

4.5.2 Test method ................................................................................................................................................... 12

4.5.3 Requirements ................................................................................................................................................ 12

4.6 Compatibility with the products used for shock disinfection of the networks...................... 12

4.6.1 General ............................................................................................................................................................. 12

4.6.2 Test method ................................................................................................................................................... 12

4.6.3 Requirements ................................................................................................................................................ 13

5 Design and dimensional requirements ................................................................................................ 13

5.1 General guidance .......................................................................................................................................... 13

5.2 Dimensional characteristics..................................................................................................................... 14

5.3 Test port and pressure measuring port ............................................................................................... 14

5.4 Expansion valve outlet connection to air break to drain............................................................... 14

5.5 Expansion valve discharge connection to drain device ................................................................. 14

5.6 Connections .................................................................................................................................................... 14

5.7 Replacing of the expansion valve ........................................................................................................... 14

5.8 Check valve ..................................................................................................................................................... 15

6 Apparatus ........................................................................................................................................................ 15

6.1 General ............................................................................................................................................................. 15

6.2 Tolerances of parameters and accuracy of measure instruments ............................................. 15

6.2.1 Tolerances on set parameters ................................................................................................................. 15

6.2.2 Accuracy of measuring instruments ..................................................................................................... 15

6.2.3 Test media ...................................................................................................................................................... 15

7 Hydraulic tests and requirements ......................................................................................................... 15

7.1 Flow rate test ................................................................................................................................................. 15

7.1.1 Procedure........................................................................................................................................................ 15

7.1.2 Requirement .................................................................................................................................................. 15

7.2 Tightness test ................................................................................................................................................. 16

7.2.1 General ............................................................................................................................................................. 16

7.2.2 Tightness test for the isolating valve at a pressure of 1,6 MPa (16 bar) .................................. 16

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SIST EN 1488:2021
EN 1488:2021 (E)

7.2.3 Expansion group tightness test ............................................................................................................... 16

8 Mechanical tests and requirements ....................................................................................................... 16

8.1 Mechanical strength .................................................................................................................................... 16

8.1.1 Pressure test of the body of the expansion group ............................................................................ 16

8.1.2 Bending moment test .................................................................................................................................. 17

8.2 Mechanical strength of the easing gear of the expansion valve ................................................... 18

8.2.1 Procedure ........................................................................................................................................................ 18

8.2.2 Requirement ................................................................................................................................................... 18

8.3 Torsional strength of the expansion group’s body ........................................................................... 18

8.3.1 General ............................................................................................................................................................. 18

8.3.2 Procedure ........................................................................................................................................................ 18

8.3.3 Requirement ................................................................................................................................................... 19

8.4 Torque test of the captive rotating nuts/tail pieces ........................................................................ 19

8.4.1 General ............................................................................................................................................................. 19

8.4.2 Procedure ........................................................................................................................................................ 19

8.4.3 Requirement ................................................................................................................................................... 19

9 Tests and requirements of the components of the expansion group ........................................ 20

9.1 Isolating valve ................................................................................................................................................ 20

9.1.1 General ............................................................................................................................................................. 20

9.1.2 General requirements ................................................................................................................................. 20

9.1.3 Test of manual operation ........................................................................................................................... 20

9.1.4 Endurance test ............................................................................................................................................... 20

9.2 Tightness between check valve and group's body ............................................................................ 21

9.2.1 General ............................................................................................................................................................. 21

9.2.2 Verification of the leak tightness between the group’s body and the check valve at

low pressure ................................................................................................................................................... 21

9.2.3 Verification of the leak tightness between the group’s body and the check valve

under high pressure .................................................................................................................................... 21

9.3 Expansion valve ............................................................................................................................................. 21

9.3.1 Pressures ......................................................................................................................................................... 21

9.3.2 Cold water pressure tests .......................................................................................................................... 22

9.4 Endurance test ............................................................................................................................................... 23

9.4.1 Procedure ........................................................................................................................................................ 23

9.4.2 Requirement ................................................................................................................................................... 23

9.5 Easing gear (manual control device) ..................................................................................................... 24

9.5.1 Operation of the easing gear ..................................................................................................................... 24

9.5.2 Easing gear endurance test ....................................................................................................................... 24

9.6 Air break to drain ......................................................................................................................................... 24

10 Acoustic tests and requirements............................................................................................................. 24

11 Classification .................................................................................................................................................. 25

12 Designation ..................................................................................................................................................... 25

13 Marking ............................................................................................................................................................ 26

14 Technical documents and presentation at delivery ......................................................................... 26

Annex A (informative) Classification of water heaters according to heating method ...................... 27

Bibliography ................................................................................................................................................................. 29

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SIST EN 1488:2021
EN 1488:2021 (E)
European foreword

This document (EN 1488:2021) 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 November 2021, and conflicting national standards

shall be withdrawn at the latest by November 2021.

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 1488:2000.

In comparison with the previous edition, the following technical modifications have been made:

— chapter on materials was completely revised;
— testing with disinfectant was introduced;
— torque test was added;
— testing for safety valve was changed and optimized;
— coating test procedure was revised;
— normative references were updated;
— editorial changes have been made throughout the entire document.

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, Turkey and the

United Kingdom.
---------------------- Page: 6 ----------------------
SIST EN 1488:2021
EN 1488:2021 (E)
Introduction

With regards to potential adverse effect on the quality of water intended for human consumption,

caused by the product covered by this document:

1) 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.

2) It should be noted that, whilst awaiting the adoption of verifiable European criteria, existing

national regulations concerning the use or the characteristics of this product remain in force.

---------------------- Page: 7 ----------------------
SIST EN 1488:2021
EN 1488:2021 (E)
1 Scope

This document specifies, dimensions, materials and performance requirements (including methods of

test) for expansion groups, of nominal sizes from DN 15 to DN 25, having working pressures from

0,1 MPa (1 bar) to 1,0 MPa (10 bar).

Expansion groups are fitted to the cold potable water supply only for expansion purposes, e.g. of

storage water heaters, having a maximum distribution temperature of 95 °C.

Expansion groups limit pressure in the water heater to which they are fitted, that is produced by

thermal expansion of the water, prevent the backflow of water into the supply pipe and prevent the

discharged water to get into contact with the water in the water heater.

Expansion groups do not control temperature and alone do not constitute the protection required for

storage water heaters.

NOTE The use of the device specified in this document does not override the need to use controls (e.g.

thermostats and thermal cut-outs) which act directly on the power sources of water heaters (for more

information see Annex A).
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 (all parts), Specifications for installations inside buildings conveying water for human

consumption

EN 1254-2, Copper and copper alloys — Plumbing fittings — Part 2: Fittings with compression ends for

use with copper tubes

EN 1567, Building valves — Water pressure reducing valves and combination water pressure reducing

valves — Requirements and tests

EN 1717:2000, Protection against pollution of potable water in water installations and general

requirements of devices to prevent pollution by backflow

EN 10226-1, Pipe threads where pressure tight joints are made on the threads — Part 1: Taper external

threads and parallel internal threads — Dimensions, tolerances and designation

EN 13959, Anti-pollution check valves — DN 6 to DN 250 inclusive family E, type A, B, C and D

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 6509 (all parts), Corrosion of metals and alloys — Determination of dezincification resistance of

copper alloys with zinc (ISO 6509)

EN ISO 228-1, Pipe threads where pressure-tight joints are not made on the threads — Part 1: Dimensions,

tolerances and designation (ISO 228-1)

EN ISO 9227, Corrosion tests in artificial atmospheres — Salt spray tests (ISO 9227)

1 All pressures are gauge unless otherwise stated.
---------------------- Page: 8 ----------------------
SIST EN 1488:2021
EN 1488:2021 (E)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.

ISO and IEC maintain terminological 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
expansion group

group that limits the pressure increase due to the volume expansion when water is heated, prevents the

backflow of the water into the main circuit and the contamination of water contained in the water

heater with discharged water, allows to control the function of the backflow prevention and isolates the

water heater for maintenance services

Note 1 to entry: An expansion group comprises of the following components in a single unit, in an upstream to

downstream order as shown in Table 1.
Table 1 — Components of the expansion group
Quantity
Component
an isolating valve 1
a test port for monitoring the check valve 1
a check valve 1
an isolating valve
an additional outlet connection
an expansion valve 1
an air break to drain 1
a pressure measuring port
optional
3.2
isolating valve
valve that isolates the water heater from the potable water supply
3.3
check valve

valve that allows water to flow into a water heater, and automatically prevents water returning to the

water supply
3.4
additional outlet connection

connection to supply cold potable water to be supplied to an additional device, e.g. inline hot water

supply tempering valves, etc.
3.5
expansion valve

valve that limits the pressure of the water in the water heater to a predetermined value by discharging

water to drain
---------------------- Page: 9 ----------------------
SIST EN 1488:2021
EN 1488:2021 (E)
3.6
air break to drain

device that prevents discharged water from returning to the expansion group and thus to the water

heater
3.7
pressure measuring port
measuring port that allows pressure measuring equipment to be connected
3.8
nominal set pressure
pressure of the expansion valve which is set on production
Note 1 to entry: The “nominal set pressure” (P ) is often called “set pressure”.
3.9
water tightness pressure
pressure up to which the expansion valve is closed
Note 1 to entry: See Figure 1.
3.10
initial opening pressure

pressure at which the expansion valve opens for the first time, as indicated by the first droplet of water

at the outlet of the expansion group, after a period of storage
Note 1 to entry: See Figure 1.
3.11
opening pressure

pressure at which the expansion valve open as indicated by the appearance of water at the outlet of the

expansion group
Note 1 to entry: See Figure 1.
3.12
rating pressure
pressure at which the discharged flow is above the limit
Note 1 to entry: See Figure 1 and Table 8.
---------------------- Page: 10 ----------------------
SIST EN 1488:2021
EN 1488:2021 (E)
3.13
closing pressure

pressure at which the expansion valve closes after having reached the rating pressure

Note 1 to entry: See Figure 1.
Key
pressure
X time
Figure 1 — Pressures
4 Materials and surface finishes
4.1 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 insufficient corrosion resistance (e.g. cast iron, aluminium) 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 recommendations or international standards.

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SIST EN 1488:2021
EN 1488:2021 (E)
4.2 Materials

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.

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 the standard

EN ISO 6509 (all parts) and the product shall be marked in compliance with the indications according to

Clause 13.
4.3 Detection of residual stress
4.3.1 General

This test shall be performed for bodies made out of brass materials and with female threads according

to EN 10226-1 and compression ends according to EN 1254-2.
4.3.2 Test

This test is based on ISO 6957. Its purpose is to verify the resistance to cracking under stress corrosion

in ammonia medium (as described in 4.3.3 b).

The test entails exposing test specimens consisting of the assembled expansion group in an atmosphere

loaded with ammonia vapour.
4.3.3 Test method (Procedure)
The paragraph below details ISO 6957.
Test solution:
a) Use solutions of analysis quality and of distilled water.
b) Solution of ammonia at 20 % (in weight).

c) The pH of the test solution is to be adjusted to 9.5 by using hydrochloric acid.

d) The test temperature is to be (23 ± 2) °C with a measurement uncertainty of ± 1 °C.

Test specimen:

e) The test specimen consists of three samples of a single assembled product. The test specimen is

inserted into the test enclosure under no stress.
---------------------- Page: 12 ----------------------
SIST EN 1488:2021
EN 1488:2021 (E)
Instructions:

f) Rinse the test specimens with a clean non-chlorinated solvent (for example, ethanol).

g) Let it dry in the air.

h) Insert the test specimens into the test enclosure along with the ammonia solution. The volume of

the container made of glass (e.g. desiccator) is to be minimum (10 ± 1) l.

i) The volume of the solution inserted is to be (200 ± 10) ml per 3 l of total volume of the container

(e.g. for a 10 l container it means (667 ± 33) ml.

j) Place the test specimens in the container in such a way that they will not touch each other and that

they will not be in contact with the solution.
k) After an exposure of 24 h , remove the test specimens and rinse them.
4.3.4 Requirements

After the test, the expansion group shall be disassembled and inspected visually for stress corrosion

cracking. No cracking shall occur on any component.
At least two samples shall be in acco
...

SLOVENSKI STANDARD
oSIST prEN 1488:2020
01-junij-2020
Ventili v stavbah - Ekspanzijski bloki - Preskusi in zahteve
Building valves - Expansion groups - Tests and requirements
Gebäudearmaturen - Sicherheitsgruppen für Expansionswasser - Prüfungen und
Anforderungen
Robinetterie de bâtiment - Groupes d'expansion - Essais et exigences
Ta slovenski standard je istoveten z: prEN 1488
ICS:
23.060.01 Ventili na splošno Valves in general
91.140.60 Sistemi za oskrbo z vodo Water supply systems
oSIST prEN 1488:2020 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
oSIST prEN 1488:2020
---------------------- Page: 2 ----------------------
oSIST prEN 1488:2020
DRAFT
EUROPEAN STANDARD
prEN 1488
NORME EUROPÉENNE
EUROPÄISCHE NORM
April 2020
ICS 91.140.60 Will supersede EN 1488:2000
English Version
Building valves - Expansion groups - Tests and
requirements

Robinetterie de bâtiment - Groupes d'expansion - Gebäudearmaturen - Sicherheitsgruppen für

Essais et exigences Expansionswasser - Prüfungen und Anforderungen

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 1488:2020 E

worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
oSIST prEN 1488:2020
prEN 1488:2020 (E)
Contents Page

European foreword ....................................................................................................................................................... 4

Introduction .................................................................................................................................................................... 5

1 Scope .................................................................................................................................................................... 6

2 Normative references .................................................................................................................................... 6

3 Terms and definitions ................................................................................................................................... 7

4 Materials and surface finishes .................................................................................................................... 9

4.1 General ................................................................................................................................................................ 9

4.2 Materials .......................................................................................................................................................... 10

4.3 Detection of residual stress ...................................................................................................................... 10

4.3.1 General ............................................................................................................................................................. 10

4.3.2 Test .................................................................................................................................................................... 10

4.3.3 Test method (Procedure) .......................................................................................................................... 10

4.3.4 Requirements ................................................................................................................................................ 11

4.4 Corrosion resistance test ........................................................................................................................... 11

4.4.1 General ............................................................................................................................................................. 11

4.4.2 Test method ................................................................................................................................................... 11

4.4.3 Requirements ................................................................................................................................................ 11

4.5 Coating adherence test ............................................................................................................................... 11

4.5.1 General ............................................................................................................................................................. 11

4.5.2 Test method ................................................................................................................................................... 11

4.5.3 Requirements ................................................................................................................................................ 12

4.6 Compatibility with the products used for shock disinfection of the networks...................... 12

4.6.1 General ............................................................................................................................................................. 12

4.6.2 Test method ................................................................................................................................................... 12

4.6.3 Requirements ................................................................................................................................................ 13

5 Design and dimensional requirements ................................................................................................ 13

5.1 General guidance .......................................................................................................................................... 13

5.2 Dimensional characteristics..................................................................................................................... 13

5.3 Test port and pressure measuring port ............................................................................................... 13

5.3.1 Expansion valve outlet connection to air break to drain............................................................... 14

5.4 Expansion valve discharge connection to drain device ................................................................. 14

5.5 Exclusions ....................................................................................................................................................... 14

5.6 Replacing of the expansion valve ........................................................................................................... 14

5.7 Check valve ..................................................................................................................................................... 14

6 Apparatus ........................................................................................................................................................ 14

6.1 General ............................................................................................................................................................. 14

6.2 Tolerances of parameters and accuracy of measure instruments ............................................. 15

6.2.1 Tolerances on set parameters ................................................................................................................. 15

6.2.2 Accuracy of measuring instruments ..................................................................................................... 15

6.2.3 Test media ...................................................................................................................................................... 15

7 Hydraulic tests and requirements ......................................................................................................... 15

7.1 Flow rate test ................................................................................................................................................. 15

7.1.1 Procedure........................................................................................................................................................ 15

7.1.2 Requirement .................................................................................................................................................. 15

7.2 Tightness test ................................................................................................................................................. 15

7.2.1 General ............................................................................................................................................................. 15

7.2.2 Tightness test for the isolating valve at a pressure of 1,6 MPa (16 bar) .................................. 16

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7.2.3 Expansion group tightness test ............................................................................................................... 16

8 Mechanical tests and requirements ....................................................................................................... 16

8.1 Mechanical strength .................................................................................................................................... 16

8.1.1 Pressure test of the body of the expansion group ............................................................................ 16

8.1.2 Bending moment test .................................................................................................................................. 16

8.2 Mechanical strength of the easing gear of the expansion valve ................................................... 18

8.2.1 Procedure ........................................................................................................................................................ 18

8.2.2 Requirement ................................................................................................................................................... 18

8.3 Torsional strength of the expansion group’s body ........................................................................... 18

8.3.1 General ............................................................................................................................................................. 18

8.3.2 Procedure ........................................................................................................................................................ 18

8.3.3 Requirement ................................................................................................................................................... 19

8.4 Torque test of the captive rotating nuts/tail pieces and backnuts ............................................. 19

8.4.1 General ............................................................................................................................................................. 19

8.4.2 Procedure ........................................................................................................................................................ 19

8.4.3 Requirement ................................................................................................................................................... 19

9 Tests and requirements of the components of the expansion group ........................................ 19

9.1 Isolating valve ................................................................................................................................................ 19

9.1.1 General requirements ................................................................................................................................. 19

9.1.2 Test of manual operation ........................................................................................................................... 20

9.1.3 Endurance test ............................................................................................................................................... 20

9.2 Tightness between check valve and valve body ................................................................................ 20

9.2.1 General ............................................................................................................................................................. 20

9.2.2 Verification of the leak tightness between the group’s body and the check valve at

low pressure ................................................................................................................................................... 20

9.2.3 Verification of the leak tightness between the group’s body and the check valve

under high pressure .................................................................................................................................... 21

9.3 Expansion valve ............................................................................................................................................. 21

9.3.1 Pressures ......................................................................................................................................................... 21

9.3.2 Cold water pressure tests .......................................................................................................................... 22

9.4 Endurance test ............................................................................................................................................... 23

9.4.1 Procedure ........................................................................................................................................................ 23

9.4.2 Requirement ................................................................................................................................................... 23

9.5 Easing gear (manual control device) ..................................................................................................... 23

9.5.1 Operation of the easing gear ..................................................................................................................... 23

9.5.2 Easing gear endurance test ....................................................................................................................... 23

9.6 Air break to drain ......................................................................................................................................... 23

10 Acoustic tests and requirements............................................................................................................. 24

11 Classification .................................................................................................................................................. 24

12 Designation ..................................................................................................................................................... 24

13 Marking ............................................................................................................................................................ 25

14 Technical documents and presentation at delivery ......................................................................... 25

Annex A (informative) Classification of water heaters according to heating method ........................ 27

Bibliography ................................................................................................................................................................. 28

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European foreword

This document (prEN 1488:2020) 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 1488:2000.

In comparison with the previous edition, the following technical modifications have been made:

— chapter on materials was completely revised;
— testing with disinfectant was introduced;
— torque test was added;
— testing for safety valve was changed and optimised;
— coating test procedure was revised;
— normative references were updated;
— editorial changes have been made throughout the entire document.
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Introduction

The product standards on check valves are currently being worked out within CEN/TC 164/WG 4. The

requirements for the endurance tests that will be laid down for these products may cause the revision of

the present document for reasons of homogeneity.

With regards to potential adverse effect on the quality of water intended for human consumption, caused

by the product covered by this document:

1) 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.

2) It should be noted that, whilst awaiting the adoption of verifiable European criteria, existing national

regulations concerning the use or the characteristics of this product remain in force.

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1 Scope

This document specifies, dimensions, materials and performance requirements (including methods of

test) for expansion groups, of nominal sizes from DN 15 to DN 25, having working pressures ) from

0,1 MPa (1 bar) to 1,0 MPa (10 bar).

Expansion groups shall be fitted to the cold potable water supply only for expansion purposes, e.g. of

storage water heaters, having a maximum distribution temperature of 95 °C.

Expansion groups limit pressure in the water heater to which they are fitted, that is produced by thermal

expansion of the water, prevent the backflow of water into the supply pipe and prevent the discharged

water to get into contact with the water in the water heater.

Expansion groups do not control temperature and alone do not constitute the protection required for

storage water heaters.

NOTE The use of the device specified in this document does not override the need to use controls (e.g.

thermostats and thermal cut-outs) which act directly on the power sources of water heaters.

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 (all parts), Specifications for installations inside buildings conveying water for human consumption

EN 1254-2, Copper and copper alloys — Plumbing fittings — Part 2: Fittings with compression ends for use

with copper tubes

EN 1567, Building valves — Water pressure reducing valves and combination water pressure reducing

valves — Requirements and tests

EN 1717:2000, Protection against pollution of potable water in water installations and general

requirements of devices to prevent pollution by backflow

EN 10226-1, Pipe threads where pressure tight joints are made on the threads — Part 1: Taper external

threads and parallel internal threads — Dimensions, tolerances and designation

EN 13959, Anti-pollution check valves — DN 6 to DN 250 inclusive family E, type A, B, C and D

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 6509, Corrosion of metals and alloys — Determination of dezincification resistance of brass

(ISO 6509)
1) All pressures are gauge unless otherwise stated.
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EN ISO 228-1, Pipe threads where pressure-tight joints are not made on the threads — Part 1: Dimensions,

tolerances and designation (ISO 228-1)
ISO 6957, Copper alloys — Ammonia test for stress corrosion resistance
EN ISO 9227, Corrosion tests in artificial atmospheres — Salt spray tests
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.

ISO and IEC maintain terminological 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
Expansion group

Limits the pressure increase due to the volume expansion when water is heated, prevents the backflow

of the water into the main circuit and the contamination of water contained in the water heater with

discharged water, allows to control the function of the backflow prevention and isolates the water heater

for maintenance services

Note 1 to entry: An expansion group comprises of at least the following components in a single unit, in an

upstream to downstream order as shown in Table 1.
Table 1 — Components of the expansion group
Component
an isolating valve 1
a test port for monitoring the check valve 1
a check valve 1
an isolating valve 1
an additional outlet connection 1
an expansion valve 1
an air break to drain 1
a pressure measuring port 1
optional
3.2
isolating valve

sllows to isolate the water heater from the potable water supply. If a second isolating valve is fitted, it

shall be between the check valve and the expansion valve
3.3
check valve

allows water to flow into a water heater, and automatically prevents water returning to the water supply

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3.4
additional outlet connection

allows cold potable water to be supplied to an additional device, e.g. inline hot water supply tempering

valves etc.
3.5
expansion valve

limits the pressure of the water in the water heater to a predetermined value by discharging water to

drain
3.6
air break to drain

prevents discharged water from returning to the expansion group and thus to the water heater

3.7
pressure measuring port
allows pressure measuring equipment to be connected
3.8
nominal set pressure (P )
pressure of the expansion valve which is set on production
Note 1 to entry: The “nominal set pressure” (P ) is often called “set pressure”.
3.9
water tightness pressure (P )
pressure up to which the expansion valve is closed
Note 1 to entry: See Figure 1.
3.10
initial opening pressure (P )

pressure at which the expansion valve opens for the first time, as indicated by the first droplet of water

at the outlet of the expansion group, after a period of storage
Note 1 to entry: See Figure 1.
3.11
opening pressure (P )

pressure at which the expansion valves open as indicated by the appearance of water at the outlet of the

expansion group
Note 1 to entry: See Figure 1.
3.12
rating pressure (P )
pressure at which the discharged flow is above the limit given in Table 9
Note 1 to entry: See Figure 1 and Table 9.
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3.13
closing pressure (P )

pressure at which the expansion valve closes after having reached the rating pressure

Note 1 to entry: See Figure 1.
Key
Y pressure
X time
Figure 1 — Pressures (see Clause 3)
4 Materials and surface finishes
4.1 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 insufficient corrosion resistance (e.g. cast iron, aluminium) 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 recommendations or international standards.

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4.2 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 the standard

EN ISO 6509 and the product shall be marked in compliance with the indications according to Clause 13.

4.3 Detection of residual stress
4.3.1 General

This test shall be performed for bodies made out of brass materials and with female threads according to

EN 10226-1 and compression ends according to EN 1254-2.
4.3.2 Test

This test is based on ISO 6957. Its purpose is to verify the resistance to cracking under stress corrosion

in ammonia medium (as described in 4.3.3 b).

The test entails exposing test specimens consisting of the assembled expansion group in an atmosphere

loaded with ammonia vapour.
4.3.3 Test method (Procedure)
The paragraph below details ISO 6957.
Test solution:
a) Use solutions of analysis quality and of distilled water.
b) Solution of ammonia at 20 % (in weight).

c) The pH of the test solution is to be adjusted to 9,5 by using hydrochloric acid.

d) The test temperature is to be (23 ± 2) °C with a measurement uncertainty of ± 1 °C.

Test specimen:

e) The test specimen consists of three samples of a single assembled product. The test specimen is

inserted into the test enclosure under no stress.
Instructions:

f) Rinse the test specimens with a clean non-chlorinated solvent (for example, ethanol).

g) Let it dry in the air.

h) Insert the test specimens into the test enclosure along with the ammonia solution. The volume of the

container made of glass (e.g. desiccator) is to be minimum (10 ± 1) l.

i) The volume of the solution inserted is to be (200 ± 10) ml per 3 l of total volume of the container (e.g.

for a 10 l container it means (667 ± 33) ml.

j) Place the test specimens in the container in such a way that they will not touch each other and that

they will not be in contact with the solution.
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k) After an exposure of 24 h , remove the test specimens and rinse them.
4.3.4 Requirements

After the test, the expansion valve shall be disassembled and inspected visually for stress corrosion

cracking. No cracking shall occur on any component.
At least two samples shall be in accordance with the test in 7.2.
4.4 Corrosion resistance test
4.4.1 General

The purpose of the corrosion resistance test is to qualify all used materials of an expansion group,

especially when used in a humid atmosphere where condensation water may occur. The whole expansion

group shall be tested, not only the parts in contact with potable water, e.g. springs, spring caps etc.

4.4.2 Test method

Samples shall be prepared for the corrosion resistance test as described as follows.

Carry out the test under the conditions described in EN ISO 9227 specifically for the neutral saline-spray

test, in the following way:

a) Subject the device to spraying for at least 100 h, interrupt the spraying treatment for (48 ± 1) h while

maintaining t
...

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