EN 1491:2022

Building valves - Expansion valves - Tests and requirements

This document specifies dimensions, materials and performance requirements (including methods of test) for expansion valves, of nominal sizes from DN 15 to DN 32, having working pressures ) from 0,1 MPa (l bar) to 1,0 MPa (10 bar).
Expansion valves are intended for fitting to the cold potable water supply of storage water heaters, having a maximum distribution temperature of 95 °C, for all energy sources.
Expansion valves do not control the temperature and alone do not constitute the protection required for storage water heaters. Expansion valves limit pressure, in the water heaters to what they are fitted, that is produced by thermal expansion of the water.
NOTE   The use of the device specified in this document does not override the need to use controls (e.g. thermostats and cut-outs) which act directly on the power sources of water heaters (for more information see Annex A).

Gebäudearmaturen - Sicherheitsventile für Expansionswasser - Prüfungen und Anforderungen

Dieses Dokument legt Abmessungen, Werkstoffe und Leistungsanforderungen (einschließlich Prüfverfahren) für Sicherheitsventile für Expansionswasser mit einer Nennweite von DN 15 bis DN 32 und Betriebsdrücken  von 0,1 MPa (1 bar) bis 1,0 MPa (10 bar) fest.
Sicherheitsventile für Expansionswasser sind für den Anschluss an die kalte Trinkwasserversorgung von Speicherwassererwärmern mit einer maximalen Gebrauchstemperatur von 95 °C, unabhängig von den verwendeten Energiequellen, bestimmt.
Das Expansionsventil für Expansionswasser überwacht nicht die Temperaturen und stellt auch nicht die einzige für einen Speicherwassererwärmer erforderliche Sicherheit dar. Das Sicherheitsventil für Expansionswasser begrenzt den durch die Wärmeausdehnung des Wassers verursachten Druckanstieg im Wassererwärmer, in den es eingebaut ist.
ANMERKUNG   Durch die Verwendung des in diesem Dokument beschriebenen Gerätes wird die Notwendigkeit zu Verwendung von Steuereinrichtungen (z. B. Thermostate und Auslöser), die direkt an den Leistungsquellen von Warmwasserbereitern zum Einsatz kommen, nicht aufgehoben (für weitere Informationen siehe Anhang A).

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

Le présent document spécifie les dimensions, les matériaux et les exigences de performance (y compris les méthodes d´essai) auxquels doivent satisfaire les soupapes d’expansion de diamètre nominal allant de DN 15 à DN 32, dont les pressions de service ) sont comprises entre 0,1 MPa (1 bar) et 1,0 MPa (10 bar).
Les soupapes d’expansion sont destinées à être montées au niveau de l’alimentation en eau potable froide des chauffe-eau à accumulation, dont la température de distribution ne dépasse pas 95 °C, quelles que soient les sources d’énergie utilisées.
Les soupapes d'expansion ne contrôlent pas la température et ne constituent pas, à elles seules, la protection nécessaire aux chauffe-eau à accumulation. Les soupapes d’expansion limitent la pression dans les chauffe-eau où elles sont montées, occasionnée par la dilatation thermique de l’eau.
NOTE   L'utilisation du dispositif spécifié dans le présent document ne doit pas prévaloir sur la nécessité d'utiliser des commandes (telles que les thermostats et dispositifs de coupure) qui agissent directement sur les sources d'énergie des chauffe-eau (pour plus d’informations, voir l’Annexe A).

Ventili v stavbah - Ekspanzijski ventili - Preskusi in zahteve

Ta dokument določa mere, materiale in tehnične zahteve (vključno s preskusnimi metodami) za ekspanzijske ventile nazivnih velikosti od DN 15 do DN 32 z delovnimi tlaki od 0,1 MPa (1 bar) do 1,0 MPa (10 barov).
Ekspanzijski ventili so namenjeni vgradnji na dovod hladne pitne vode akumulacijskih grelnikov vode z najvišjo distribucijsko temperaturo 95 °C za vse vire energije.
Ekspanzijski ventili ne regulirajo temperature in sami po sebi ne predstavljajo zaščite, zahtevane za akumulacijske grelnike vode. Ekspanzijski ventili omejujejo tlak, ki nastane zaradi toplotnega raztezanja vode v grelnikih vode, v katere so vgrajeni.
OPOMBA:   Uporaba naprave, navedene v tem dokumentu, ne izključuje zahteve za uporabo krmilnikov (npr. termostatov in izklopnih stikal), ki delujejo neposredno na vire napajanja grelnikov vode (za več informacij glej dodatek A).

General Information

• Status: Published
• Publication Date: 30-Oct-2022
• Withdrawal Date: 30-Jan-2023
• ICS: 91.140.60 - Water supply systems
• Technical Committee: CEN/TC 164 - Water supply
• Drafting Committee: CEN/TC 164/WG 14 - Valves and fitting for buildings and devices to prevent pollution by backflow
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 20-Jul-2022
• Due Date: 04-Dec-2021
• Completion Date: 20-Jul-2022
• Directive: 98/83/EC - Quality of water intended for human consumption
• Ref Project: SIST EN 1491:2022 - Building valves - Expansion valves - Tests and requirements

Relations

• Replaces: EN 1491:2000 - Building valves - Expansion valves - Tests and requirements
• Effective Date: 26-Jun-2019

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN 1491:2022
01-september-2022
Nadomešča:
SIST EN 1491:2000
Ventili v stavbah - Ekspanzijski ventili - Preskusi in zahteve
Building valves - Expansion valves - Tests and requirements
Gebäudearmaturen - Sicherheitsventile für Expansionswasser - Prüfungen und
Anforderungen
Robinetterie de bâtiment - Soupapes d'expansion - Essais et exigences
Ta slovenski standard je istoveten z: EN 1491:2022
ICS:
23.060.01 Ventili na splošno Valves in general
91.140.60 Sistemi za oskrbo z vodo Water supply systems
SIST EN 1491:2022 en,fr,de

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

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SIST EN 1491:2022
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SIST EN 1491:2022
EN 1491
EUROPEAN STANDARD
NORME EUROPÉENNE
July 2022
EUROPÄISCHE NORM
ICS 91.140.60 Supersedes EN 1491:2000
English Version
Building valves - Expansion valves - Tests and
requirements

Robinetterie de bâtiment - Soupapes d'expansion - Gebäudearmaturen - Sicherheitsventile für

Essais et exigences Expansionswasser - Prüfungen und Anforderungen
This European Standard was approved by CEN on 13 June 2022.

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

© 2022 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 1491:2022 E

worldwide for CEN national Members.
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SIST EN 1491:2022
EN 1491:2022 (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 .......................................................................................................... 8

4.1 General ...................................................................................................................................................... 8

4.2 Materials ................................................................................................................................................... 9

4.3 Detection of residual stress ............................................................................................................... 9

4.3.1 General ...................................................................................................................................................... 9

4.3.2 Test ............................................................................................................................................................. 9

4.3.3 Test method (Procedure) ................................................................................................................... 9

4.3.4 Requirements .......................................................................................................................................10

4.4 Corrosion resistance test ..................................................................................................................10

4.4.1 General ....................................................................................................................................................10

4.4.2 Test method ..........................................................................................................................................10

4.4.3 Requirements .......................................................................................................................................10

4.5 Coating adherence test ......................................................................................................................10

4.5.1 General ....................................................................................................................................................10

4.5.2 Test method ..........................................................................................................................................10

4.5.3 Requirements .......................................................................................................................................11

4.6 Compatibility with the products used for shock disinfection of the networks.............11

4.6.1 General ....................................................................................................................................................11

4.6.2 Test method ..........................................................................................................................................11

4.6.3 Requirements .......................................................................................................................................11

5 Design, dimensional and pressure requirements ...................................................................12

5.1 General guidance .................................................................................................................................12

5.2 Dimensional characteristics............................................................................................................12

5.2.1 Nominal outlet diameter ..................................................................................................................12

5.2.2 End connections ...................................................................................................................................12

5.3 Expansion valve outlet connection to air break to drain......................................................12

5.4 Expansion valve discharge connection to drain service .......................................................12

5.5 Connections ...........................................................................................................................................12

5.6 Pressures ................................................................................................................................................13

5.6.1 General ....................................................................................................................................................13

5.6.2 Nominal set pressure (P ) ...............................................................................................................13

5.6.3 Water tightness pressure (P ) .........................................................................................................13

5.6.4 Opening pressure (Po) ........................................................................................................................13

5.6.5 Rating pressure (P ) ..........................................................................................................................13

5.6.6 Clossing pressure (P ) .........................................................................................................................13

5.6.7 Initial opening pressure (P ) ..........................................................................................................13

6 Apparatus ...............................................................................................................................................13

6.1 General ....................................................................................................................................................13

6.2 Tolerances of parameters and accuracy of measure instruments ....................................14

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SIST EN 1491:2022
EN 1491:2022 (E)

6.2.1 Tolerances on set parameters ....................................................................................................... 14

6.2.2 Accuracy of measuring instruments ............................................................................................ 14

6.2.3 Test media ............................................................................................................................................. 14

7 Hydraulic tests and requirements ................................................................................................ 14

7.1 Cold water pressure tests ................................................................................................................ 14

7.1.1 General ................................................................................................................................................... 14

7.1.2 Water tightness pressure (P ) test ................................................................................................ 14

7.1.3 Repeat tests ........................................................................................................................................... 15

7.2 Endurance test ..................................................................................................................................... 15

7.2.1 Procedure .............................................................................................................................................. 15

7.2.2 Requirement ......................................................................................................................................... 16

7.3 Easing gear (manual control device) ........................................................................................... 16

7.3.1 Operation of the easing gear........................................................................................................... 16

7.3.2 Easing gear endurance test ............................................................................................................. 16

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

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

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

8.1.2 Bending moment test of the body of the expansion valve ................................................... 17

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

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

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

8.3 Torsional strength of the expansion valve'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 Classification ........................................................................................................................................ 19

10 Designation ........................................................................................................................................... 20

11 Marking .................................................................................................................................................. 20

12 Technical documents and presentation at delivery ............................................................... 21

Annex A (informative) Classification of water heaters according to heating method ............ 22

A.1 Indirect heating ................................................................................................................................... 22

A.2 Classification of water heaters according to heating method ............................................ 22

A.2.1 Indirect heating ................................................................................................................................... 22

A.2.2 Direct heating ....................................................................................................................................... 23

Bibliography ....................................................................................................................................................... 24

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SIST EN 1491:2022
EN 1491:2022 (E)
European foreword

This document (EN 1491:2022) 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 January 2023, and conflicting national standards shall

be withdrawn at the latest by January 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 1491:2000.

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 of the expansion valve was changed and optimized;
— coating test procedure was revised;
— normative references were updated;
— editorial changes have been made throughout the entire document.

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, Turkey and the United

Kingdom.
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SIST EN 1491:2022
EN 1491:2022 (E)
Introduction

With regard 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 and or the characteristics of this product remain in force.

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SIST EN 1491:2022
EN 1491:2022 (E)
1 Scope

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

test) for expansion valves, of nominal sizes from DN 15 to DN 32, having working pressures ) from

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

Expansion valves are intended for fitting to the cold potable water supply of storage water heaters, having

a maximum distribution temperature of 95 °C, for all energy sources.

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

storage water heaters. Expansion valves limit pressure, in the water heaters to what they are fitted, that

is produced by thermal expansion of the water.

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

thermostats and 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: Compression fittings for use with copper

tubes

EN 1717, 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 ISO 6509 (all parts), Corrosion of metals and alloys - Determination of dezincification resistance of brass

(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)

ISO 6957, Copper alloys — Ammonia test for stress corrosion resistance
All pressures are gauge unless otherwise stated.
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SIST EN 1491:2022
EN 1491:2022 (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:

— IEC Electropedia: available at https://www.electropedia.org/
— ISO Online browsing platform: available at https://www.iso.org/obp
3.1
expansion valve

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

water to drain
3.2
air break to drain

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

3.3
nominal set pressure
Pnr
pressure of the expansion valve which is set on production
Note 1 to entry: The “nominal set pressure” (P ) is often called “set pressure”.
Key
Y pressure
X time
Figure 1 — Pressures
3.4
water tightness pressure
pressure up to which the expansion valve is closed
Note 1 to entry: See Figure 1.
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SIST EN 1491:2022
EN 1491:2022 (E)
3.5
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 valve, after a period of storage
Note 1 to entry: See Figure 1.
3.6
opening pressure

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

expansion valve
Note 1 to entry: See Figure 1.
3.7
rating pressure
pressure at which the discharged flow is above the limit
Note 1 to entry: See Figure 1 and Table 2.
3.8
closing pressure

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

Note 1 to entry: See Figure 1.
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 1491:2022
EN 1491:2022 (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 It is pointed out that 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

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

Clause 11.
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 valve 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 shall be adjusted to 9,5 by using hydrochloric acid.

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

Test specimen:

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

be 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) shall be minimum (10 ± 1) l.
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SIST EN 1491:2022
EN 1491:2022 (E)

i) The volume of the solution inserted shall 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.
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 crackings shall occur on any component.
At least two samples shall be in accordance with the test in 7.1.2.
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 valve,

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

valve 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 the heat in the tank and resume the spraying treatment for another (100 ± 1) h.

b) For the duration of the tests, the tank should only be opened to check and maintain the conditions,

the maximum rest period in spraying being 30 min per day. The heating should not be interrupted;

samples under test should not be handled, washed or checked.

After treatment and before visual examination, rinse the test samples in water to remove any salt residue.

4.4.3 Requirements
The expansion valve shall comply with the requirements as included in 7.1.

After the test, the expansion valve shall be disassembled and inspected visually for corrosion. No

corrosion shall occur on any component.
4.5 Coating adherence test
4.5.1 General

The coating adherence test is only applicable for the valve housing and if the purpose of the coating is

corrosion protection as specified in 4.1 c).
4.5.2 Test method

At 3 different locations on the coated surface, cut with a cutting tool with a tungsten carbide tip of the

type shown on Figure 2, crosses or V’s approximately 10 mm × 10 mm in length. The crosses or V’s shall

be cut by pulling the handle of the chisel parallel to the surface. The depth shall be such that they

completely cut through the coating layer, without forcing the coating into the base metal.

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SIST EN 1491:2022
EN 1491:2022 (E)
a) Front view b) Side view
Figure 2 — Cutting tool
4.5.3 Requirements
The coating shall neither scale nor unstick.
4.6 Compatibility with the products used for shock disinfection of the networks
4.6.1 General

All the constituent parts of the device, and in particular those made of elastomer, shall be compatible with

the treated water used for the shock disinfection of the networks using sodium hypochlorite, hydrogen

peroxide or chlorine dioxide.
4.6.2 Test method

The compatibility is checked by exposing the internal parts of the device to the chemicals as specified in

Table 1.
Table 1 — Test chemicals
Chemical Chemical Contact
Concentration Temperature
formula solution time
sodium 100 mg in 1 l demineralized
NaOCl 24 h ambient
hypochlorite water
H O
hydrogen peroxide 24 h 1 g in 1l demineralized water ambient
2 2
6 mg in 1 l demineralized
ClO
chlorine dioxide 12 h ambient
water
The quality of the water used for this test shall be pH (7 ± 0,5).

Each of the contacts being carried out under a static pressure of 0,3 MPa ± 0,1 MPa (3 bar ± 1 bar)

measured upstream.

The test shall be carried out with at least one of the given chemicals as specified in Table 1.

4.6.3 Requirements
After the performance of the test the valve shall comply with 7.1.
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SIST EN 1491:2022
EN 1491:2022 (E)
5 Design, dimensional and pressure requirements
5.1 General guidance

a) The expansion valve shall be of the type where the spring is isolated from the water by a diaphragm

or equivalent.

b) All sliding elements of the expansion valve shall be designed to prevent any risk of seizure or sticking.

c) Sliding or rotating parts of expansion valves shall not be in contact with water.

d) The components controlling the setting of the expansion valve shall no
...

SLOVENSKI STANDARD
oSIST prEN 1491:2021
01-april-2021
Ventili v stavbah - Ekspanzijski ventili - Preskusi in zahteve
Building valves - Expansion valves - Tests and requirements
Gebäudearmaturen - Sicherheitsventile für Expansionswasser - Prüfungen und
Anforderungen
Robinetterie de bâtiment - Soupapes d'expansion - Essais et prescriptions
Ta slovenski standard je istoveten z: prEN 1491
ICS:
91.140.60 Sistemi za oskrbo z vodo Water supply systems
oSIST prEN 1491:2021 en,fr,de

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

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oSIST prEN 1491:2021
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oSIST prEN 1491:2021
DRAFT
EUROPEAN STANDARD
prEN 1491
NORME EUROPÉENNE
EUROPÄISCHE NORM
February 2021
ICS 91.140.60 Will supersede EN 1491:2000
English Version
Building valves - Expansion valves - Tests and
requirements

Robinetterie de bâtiment - Soupapes d'expansion - Gebäudearmaturen - Sicherheitsventile für

Essais et prescriptions 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

© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 1491:2021 E

worldwide for CEN national Members.
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oSIST prEN 1491:2021
prEN 1491:2021 (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 ................................................................................................................... 8

4.1 General................................................................................................................................................................ 8

4.2 Materials ............................................................................................................................................................ 9

4.3 Detection of residual stress ......................................................................................................................... 9

4.3.1 General................................................................................................................................................................ 9

4.3.2 Test ....................................................................................................................................................................... 9

4.3.3 Test method (Procedure) ............................................................................................................................. 9

4.3.4 Requirements ................................................................................................................................................. 10

4.4 Corrosion resistance test ........................................................................................................................... 10

4.4.1 General.............................................................................................................................................................. 10

4.4.2 Test method .................................................................................................................................................... 10

4.4.3 Requirements ................................................................................................................................................. 10

4.5 Coating adherence test................................................................................................................................ 10

4.5.1 General.............................................................................................................................................................. 10

4.5.2 Test method .................................................................................................................................................... 10

4.5.3 Requirements ................................................................................................................................................. 11

4.6 Compatibility with the products used for shock disinfection of the networks ...................... 11

4.6.1 General.............................................................................................................................................................. 11

4.6.2 Test method .................................................................................................................................................... 11

4.6.3 Requirements ................................................................................................................................................. 12

5 Design, dimensional and pressure requirements ............................................................................. 12

5.1 General guidance .......................................................................................................................................... 12

5.2 Dimensional characteristics ..................................................................................................................... 12

5.2.1 Nominal outlet diameter ............................................................................................................................ 12

5.2.2 End connections ............................................................................................................................................ 12

5.3 Expansion valve outlet connection to air break to drain ............................................................... 12

5.4 Expansion valve discharge connection to drain service ................................................................. 13

5.5 Connections ..................................................................................................................................................... 13

5.6 Pressures ......................................................................................................................................................... 13

5.6.1 General.............................................................................................................................................................. 13

5.6.2 Nominal set pressure (P ) ........................................................................................................................ 13

5.6.3 Water tightness pressure (P ) .................................................................................................................. 13

5.6.4 Opening pressure (Po) ................................................................................................................................. 13

5.6.5 Rating pressure (P ) ................................................................................................................................... 13

5.6.6 Clossing pressure (P ) .................................................................................................................................. 13

5.6.7 Initial opening pressure (P ) ................................................................................................................... 13

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

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

6.2 Tolerances of parameters and accuracy of measure instruments .............................................. 14

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6.2.1 Tolerances on set parameters ................................................................................................................. 14

6.2.2 Accuracy of measuring instruments ...................................................................................................... 14

6.2.3 Test media ....................................................................................................................................................... 14

7 Hydraulic tests and requirements .......................................................................................................... 14

7.1 Cold water pressure tests .......................................................................................................................... 14

7.1.1 General ............................................................................................................................................................. 14

7.1.2 Water tightness pressure (P ) test ......................................................................................................... 14

7.1.3 Repeat tests ..................................................................................................................................................... 15

7.2 Endurance test ............................................................................................................................................... 15

7.2.1 Procedure ........................................................................................................................................................ 15

7.2.2 Requirement ................................................................................................................................................... 16

7.3 Easing gear (manual control device) ..................................................................................................... 16

7.3.1 Operation of the easing gear..................................................................................................................... 16

7.3.2 Easing gear endurance test ....................................................................................................................... 16

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

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

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

8.1.2 Bending moment test of the body of the expansion valve ............................................................. 17

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

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

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

8.3 Torsional strength of the expansion valve's body ............................................................................ 18

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

8.3.2 Procedure ........................................................................................................................................................ 19

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 Classification .................................................................................................................................................. 20

10 Designation ..................................................................................................................................................... 20

11 Marking ............................................................................................................................................................ 20

12 Technical documents and presentation at delivery ......................................................................... 21

Annex A (informative) Classification of water heaters according to heating method ...................... 22

A.1 Indirect heating ............................................................................................................................................. 22

A.2 Classification of water heaters according to heating method ...................................................... 22

A.2.1 Indirect heating ............................................................................................................................................. 22

A.2.2 Direct heating ................................................................................................................................................. 23

Bibliography ................................................................................................................................................................. 24

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oSIST prEN 1491:2021
prEN 1491:2021 (E)
European foreword

This document (prEN 1491:2021) 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 1491:2000.

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 of the expansion valve was changed and optimized;
— coating test procedure was revised;
— normative references were updated;
— editorial changes have been made throughout the entire document.
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Introduction

With regard 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 and 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 valves, of nominal sizes from DN 15 to DN 32, having working pressures ) from

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

Expansion valves are intended for fitting to the cold potable water supply of storage water heaters,

having a maximum distribution temperature of 95 °C, for all energy sources.

Expansion valves do not control the temperature and alone do not constitute the protection required

for storage water heaters. Expansion valves limit pressure, in the water heaters to what they are fitted,

that is produced by thermal expansion of the water.

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

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

with copper tubes

EN 1717, 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 ISO 6509 (all parts), Corrosion of metals and alloys - Determination of dezincification resistance of

brass (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)

All pressures are gauge unless otherwise stated.
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oSIST prEN 1491:2021
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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:

— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at https://www.iso.org/obp
3.1
expansion valve

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

water to drain
3.2
air break to drain

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

heater
3.3
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”.
Key
Y pressure
X time
Figure 1 — Pressures
3.4
water tightness pressure
pressure up to which the expansion valve is closed
Note 1 to entry: See Figure 1.
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3.5
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 valve, after a period of storage
Note 1 to entry: See Figure 1.
3.6
opening pressure

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

the expansion valve
Note 1 to entry: See Figure 1.
3.7
rating pressure
pressure at which the discharged flow is above the limit
Note 1 to entry: See Figure 1 and Table 2.
3.8
closing pressure

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

Note 1 to entry: See Figure 1.
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 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 It is pointed out that 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

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

Clause 11.
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 valve 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.
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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.
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 crackings shall occur on any component.
At least two samples shall be in accordance with the test in 7.1.2.
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 valve,

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

expansion valve 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 the heat in the tank and resume the spraying treatment for another 100 ± 1 h.

b) For the duration of the tests, the tank should only be opened to check and maintain the conditions,

the maximum rest period in spraying being 30 min per day. The heating should not be interrupted;

samples under test should not be handled, washed or checked.

After treatment and before visual examination, rinse the test samples in water to remove any salt

residue.
4.4.3 Requirements
The expansion valve shall comply with the requirements as included in 7.1.

After the test, the expansion valve shall be disassembled and inspected visually for corrosion. No

corrosion shall occur on any component.
4.5 Coating adherence test
4.5.1 General

The coating adherence test is only applicable for the valve housing and if the purpose of the coating is

corrosion protection as defined in 4.1 c).
4.5.2 Test method

At 3 different locations on the coated surface, cut with a cutting tool with a tungsten carbide tip of the

type shown on Figure 2, crosses or V’s approximately 10 mm × 10 mm in length. The crosses or V’s shall

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be cut by pulling the handle of the chisel parallel to the surface. The depth shall be such that they

completely cut through the coating layer, without forcing the coating into the base metal.

a) Front view b) Side view
Figure 2 — Cutting tool
4.5.3 Requirements
The coating shall neither scale nor unstick.
4.6 Compatibility with the products used for shock disinfection of the networks
4.6.1 General

All the constituent parts of the device, and in particular those made of elastomer, shall be compatible

with the treated water used for the shock disinfection of the networks using sodium hypochlorite,

hydrogen peroxide or chlorine dioxide.
4.6.2 Test method

The compatibility is checked by exposing the internal parts of the device to the chemicals as defined in

Table 1.
Table 1 — Test chemicals
Chemical Chemical
Contact time Concentration Temperature
formula solution
100 mg in 1 l
sodium
NaOCl 24 h demineralized ambient
hypochlorite
water
1 g in 1l
hydrogene
H O
24 h demineralized ambient
2 2
peroxide
water
6 mg in 1 l
ClO
chlorine dioxide 12 h demineralized ambient
water
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The quality of the water used for this test shall be ph (7 ± 0,5).

Each of the contacts being carried out under a static pressure of 0,3 MPa ± 0,1 MPa (3 bar ± 1 bar)

measured upstream.

The test shall be carried out with at least one of the given chemicals as defined in Table 1.

4.6.3 Requirements
After the performance of the test the valve shall comply with 7.1.
5 Design, dimensional and pressure requirements
5.1 General guidance

a) The expansion valve shall be of the type where the spring is isolated from the water by a diaphragm

or equivalent.

b) All sliding elements of the expansion valve shall be designed to prevent any risk of seizure or

sticking.

c) Sliding or rotating parts of expansion valves shall not be in contact with water.

d) The components controlling the setting of the expansion valve shall not be accessible to the end

user without damage to the valve.
e) Wing or similar guide
...