oSIST prEN 1488:2026

• Abstract:

  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).

• Status: Not Published
• Public Enquiry End Date: 24-Nov-2026
• ICS: 23.060.01 - Valves in general
• ICS: 91.140.60 - Water supply systems
• Technical Committee: IOVO - Water supply and waste water engineering
• Current Stage: 4020 - Public enquire (PE) (Adopted Project)
• Start Date: 02-Oct-2026
• Due Date: 19-Feb-2027
• Directive: 98/83/EC - Quality of water intended for human consumption
• Ref Project: prEN 1488 - Building valves - Expansion groups - Tests and requirements

• Referred By: SIST EN ISO 11970:2026 - Specification and qualification of welding procedures for production welding of steel castings (ISO 11970:2025)
• Effective Date: 28-Jan-2026
• Referred By: SIST EN ISO 15614-9:2026 - Specification and qualification of welding procedures for metallic materials - Welding procedure test - Part 9: Underwater hyperbaric wet welding (ISO 15614-9:2025)
• Effective Date: 28-Jan-2026
• Referred By: SIST EN 14025:2024 - Tanks for the transport of dangerous goods - Metallic pressure tanks - Design and construction
• Effective Date: 28-Jan-2026
• Revises: SIST EN 1488:2021 - Building valves - Expansion groups - Tests and requirements
• Effective Date: 18-Dec-2024

oSIST prEN 1488:2026 is the SIST publication of prEN 1488, a CEN draft European Standard for building valves - expansion groups. It specifies the dimensions, materials and performance requirements, including test methods, for expansion groups used on the cold potable water supply of storage water heaters. The document is aimed at manufacturers, test laboratories, installers, specifiers and buyers who need a defined product for managing thermal expansion in potable water systems.

What does oSIST prEN 1488:2026 specify?

oSIST prEN 1488:2026 specifies expansion groups for nominal sizes DN 15 to DN 25 and working pressures from 0,1 MPa to 1,0 MPa. These devices are fitted only to the cold potable water supply for expansion purposes, for example on storage water heaters with a maximum distribution temperature of 95 °C.

The standard describes a unit that limits pressure rise caused by heated water, prevents backflow into the supply pipe and keeps discharged water separate from the water in the heater. It also makes clear that an expansion group does not control temperature and is not, by itself, the full protection needed for storage water heaters. Annex A points readers to the additional controls that act directly on the water heater power source.

The document is organized in clauses 1 to 15, with three informative annexes.

Annex	What it covers
Annex A	Test sequences
Annex B	Classification of water heaters according to heating method
Annex C	Disinfection of test rig

What are the key requirements of oSIST prEN 1488:2026?

oSIST prEN 1488:2026 combines product design rules with a defined test programme. The main practical point is that the device must keep working as a pressure-limiting, backflow-preventing and maintainable assembly after hydraulic, mechanical, corrosion and disinfection checks.

Scope of the device and functional layout

Clause 3 defines the expansion group as a single unit made up of an isolating valve, test port, check valve, second isolating valve, additional outlet connection, expansion valve, air break to drain and pressure measuring port. For the reader, this means the product is not just one valve - it is a functional assembly with a defined order and purpose for each part.

Clause 6 adds design rules that matter in use. The expansion valve spring must be separated from the water by a diaphragm or equivalent, sliding parts must not seize, and setting controls must not be reachable by the end user without damage. The device also needs a way to check operation regularly, and if the rotary control works in only one direction, that direction is counterclockwise.

Materials, corrosion and disinfection resistance

Clause 4 requires corrosion-resistant materials or protection against corrosion, and coatings must not impair function. Where dezincification-resistant copper alloy is required, the material has to meet the stated dezincification criterion and the product must be marked accordingly. In practice, this is about keeping brass parts and coatings reliable in long-term potable-water service.

Clause 4 also includes a corrosion resistance test for the whole device, not just wetted parts, and the result must stay within the permitted change in performance. Clause 5 adds a disinfection compatibility test so the device can continue to function after shock disinfection in a drinking water installation. Annex C gives the test rig arrangement for that procedure.

Clause 4.5 covers detection of residual stress for brass bodies with female threads and compression ends. The body is exposed to an ammonia-based stress-corrosion test and must show no cracking. This matters because threaded brass bodies are vulnerable to cracking if manufacturing stresses remain in the metal.

Hydraulic performance and pressure behavior

Clause 8 sets the flow rate test and tightness checks. The device must achieve the minimum flow rate for its nominal size, and both the isolating valve and the complete device must remain leak-tight under the specified test conditions. For buyers and inspectors, this separates a product that merely fits from one that can pass water reliably without seepage.

Clause 10.3 defines how the expansion valve is judged against its nominal set pressure. The document links water-tightness, opening, discharge and closing behavior to that set pressure, and the valve must open, discharge and reclose within the required band. Repeated pressure checks must give consistent results.

Mechanical strength and endurance

Clause 9 checks that the body and controls survive installation and handling. The body is pressure-tested, the assembly is loaded with bending and torsional forces, and captive rotating nuts or tail pieces are checked for torque resistance. The practical point is that the valve must tolerate pipework stresses and installation torque without visible damage or permanent deformation.

Clause 10 goes further with endurance testing of the isolating valve, the expansion valve and the operating control. These repeated-cycle tests show whether the device keeps sealing and operating after use over time. For maintenance teams, that means the functional parts should still move and reseal after service life exposure.

Acoustics, classification, marking and delivery information

Clause 11 assigns acoustic groups based on noise emission from the cold-water flow passages. Clause 12 then classifies expansion groups by nominal size and by the water-heater limits they can be used with. Clause 13 defines the designation format, and Clause 14 lists the permanent marking needed on the product, including manufacturer identification, nominal size, set pressure, flow direction and acoustic class.

Clause 15 requires technical documentation with installation, use, inspection and maintenance information. It also includes the practical notices about upstream pressure reduction where needed, normal dripping during heating, and the need for manual operation after installation.

What terms does oSIST prEN 1488:2026 define?

• Expansion group - A combined assembly that limits pressure rise from heated water, prevents backflow, allows backflow-prevention checks and isolates the water heater for maintenance.
• Isolating valve - The valve that separates the water heater from the potable water supply.
• Check valve - The valve that allows flow into the heater and automatically stops reverse flow to the supply.
• Expansion valve - The valve that limits heater pressure by discharging water to drain.
• Air break to drain - A vertical separation or full disconnection that prevents contaminated water from re-entering the system.
• Nominal set pressure (Pnr) - The pressure value set during production for the expansion valve.
• Acoustic group - The noise class assigned from laboratory measurement of cold-water noise emission.

Who uses oSIST prEN 1488:2026?

oSIST prEN 1488:2026 is used by manufacturers of building valves and water-heater safety components, by test laboratories that run type tests and endurance tests, and by certification or compliance teams that assess product conformity. It is also relevant to installers and designers of potable-water and storage-water-heater systems who need the right device for the heating method, pressure range and installation conditions.

What changed in oSIST prEN 1488:2026 from the previous edition?

oSIST prEN 1488:2026 supersedes EN 1488:2021. The foreword states these significant technical changes:

• the materials chapter was completely revised;
• disinfection testing was introduced;
• a torque test was added;
• the safety-valve testing was changed and optimized;
• the coating test procedure was revised;
• the normative references were updated;
• editorial changes were made throughout the document.

Which standards are used with oSIST prEN 1488:2026?

Standard	Contribution in this document
EN 806 (all parts)	Installation requirements for water systems in buildings
EN 1717	Backflow protection and discharge connection conditions
EN 10226-1	Taper external and parallel internal threads
EN 1254-2	Compression fittings for copper tubes
EN 13959	Check valve functional reference
EN ISO 228-1	Parallel pipe-thread dimensions and designation
EN ISO 3822-1	Acoustic measurement method
EN ISO 3822-3	Acoustic mounting and operating conditions
EN ISO 9227	Neutral salt-spray corrosion test
EN ISO 6509-1	Dezincification resistance test for copper alloys
ISO 6957	Ammonia test for stress corrosion resistance
EN 1487, EN 1489, EN 1490, EN 1491	Related building-valve safety device standards named in Annex B and the bibliography
EN 1567	Pressure reducing valve reference in the installation notes
EN 1213, EN 13828, EN 14597, EN 1254-20	Related standards named in the bibliography and annexes for valves, controls and fittings

What does the oSIST prEN 1488:2026 document contain?

oSIST prEN 1488:2026 contains detailed test methods for corrosion, residual stress, disinfection compatibility, hydraulic flow and tightness, mechanical strength, torque resistance, endurance and acoustic performance. It also includes pressure definitions and test diagrams, plus tables for port dimensions, flow rates, bending moments, discharge flow rates, acoustic groups and classification limits.

The annexes add practical support for testing and selection. Annex A gives the test sequence, Annex B helps match the device to the water-heating method, and Annex C shows how to disinfect the test rig. For engineering teams, the document is therefore both a product specification and a test-and-marking guide.

SLOVENSKI STANDARD
01-november-2026
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
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
EUROPEAN STANDARD
NORME EUROPÉENNE
EUROPÄISCHE NORM
September 2026
ICS 91.140.60 Will supersede EN 1488:2021
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, Türkiye 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
© 2026 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 1488:2026 E
worldwide for CEN national Members.

Contents Page
European foreword . 4
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Materials . 9
4.1 General. 9
4.2 Dezincification resistant copper alloy . 9
4.3 Surface coating . 9
4.4 Corrosion . 9
4.4.1 General. 9
4.4.2 Corrosion resistance test . 10
4.5 Detection of residual stress . 10
4.5.1 General. 10
4.5.2 Principle . 10
4.5.3 Procedure . 10
4.5.4 Requirements . 11
5 Compatibility of the expansion group with disinfection . 11
5.1 General. 11
5.2 Requirements . 11
5.3 Procedure . 11
6 Design and dimensional characteristics . 12
6.1 General. 12
6.2 Dimensional characteristics . 12
6.3 Test port and pressure measuring port. 12
6.4 Expansion valve outlet connection to air break to drain . 13
6.5 Expansion valve discharge connection to drain device . 13
6.6 Connections . 13
6.7 Replacing of the expansion valve . 13
6.8 Check valve . 13
7 Apparatus . 14
7.1 General. 14
7.2 Tolerances of parameters and accuracy of measure instruments . 14
7.2.1 Tolerances on set parameters . 14
7.2.2 Accuracy of measuring instruments . 14
7.2.3 Test media . 14
8 Hydraulic tests . 14
8.1 Flow rate test . 14
8.1.1 Procedure . 14
8.1.2 Requirements . 14
8.2 Tightness test . 15
8.2.1 General. 15
8.2.2 Tightness test for the isolating valve at a pressure of 1,6 MPa (16 bar) . 15
8.2.3 Tightness test for the expansion group . 15
9 Mechanical tests . 15
9.1 Mechanical strength tests . 15
9.1.1 Pressure test of the body of the expansion group . 15
9.1.2 Bending moment test . 16
9.2 Mechanical strength test of the operating control of the expansion valve . 16
9.2.1 Procedure . 16
9.2.2 Requirements . 17
9.3 Torsional strength test of the expansion group’s body . 17
9.3.1 General . 17
9.3.2 Procedure . 17
9.3.3 Requirements . 17
9.4 Torque test of the captive rotating nuts/tail pieces . 17
9.4.1 General . 17
9.4.2 Procedure . 17
9.4.3 Requirements . 18
10 Expansion group component tests . 18
10.1 Isolating valve . 18
10.1.1 General . 18
10.1.2 Manual operation test . 18
10.1.3 Endurance test . 19
10.2 Tightness between check valve and group’s body . 19
10.2.1 General . 19
10.2.2 Leak tightness between the group’s body and the check valve at low pressure . 19
10.2.3 Leak tightness between the group’s body and the check valve under high pressure. 19
10.3 Expansion valve . 19
10.3.1 Pressures . 19
10.3.2 Cold water pressure tests . 20
10.3.3 Repeat tests . 21
10.4 Endurance test . 21
10.4.1 Procedure . 21
10.4.2 Requirements . 22
10.5 Operating control tests . 22
10.5.1 Operation test . 22
10.5.2 Endurance test . 22
10.6 Air break to drain . 22
11 Acoustic tests . 22
12 Classification . 23
13 Designation . 23
14 Marking . 23
15 Technical documents and presentation at delivery . 24
Annex A (informative) Test sequences . 26
Annex B (informative) Classification of water heaters according to heating method . 28
Annex C (informative) Disinfection of test rig . 30
Bibliography . 31

European foreword
This document (prEN 1488:2026) 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 1488:2021.
— 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.
Introduction
With regards to potential adverse effect on the quality of water intended for human consumption, caused
by the product covered by this document:
a) This document provides no information as to whether the product may be used without restriction
in any of the Member States of the EU or EFTA.
b) It should be noted that, whilst awaiting the adoption of verifiable European criteria, existing national
regulations concerning the use or the characteristics of this product remain in force.
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: Compression fittings for use with copper
tubes
EN 1717, Protection against pollution of water intended for human consumption in potable water
installations and general requirements for 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 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 3822-1, Acoustics - Laboratory tests on noise emission from appliances and equipment used in water
supply installations - Part 1: Method of measurement (ISO 3822-1:1999)
EN ISO 3822-3, Acoustics - Laboratory tests on noise emission from appliances and equipment used in water
supply installations - Part 3: Mounting and operating conditions for in-line valves and appliances (ISO 3822-
3:2018)
EN ISO 9227, Corrosion tests in artificial atmospheres - Salt spray tests (ISO 9227)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.

All pressures are gauge unless otherwise stated.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp/
— IEC Electropedia: available at https://www.electropedia.org/
3.1
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.
Note 2 to entry: For the purpose of this standard the expansion group is hereafter referred as the “device”.
Table 1 — Components of the expansion group
Component Quantity
an isolating valve 1
a test port for monitoring the check valve 1
a check valve 1
a
an isolating valve 1
a
an additional outlet connection 1
an expansion valve 1
an air break to drain 1
a
a pressure measuring port 1
a
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
3.6
air break to drain
vertical distance realised by air inlets or full disconnection between the lowest point of the outlet and
spill over level of the atmospheric over flow
3.7
pressure measuring port
measuring port that allows pressure measuring equipment to be connected
3.8
nominal set pressure
P
nr
pressure of the expansion valve which is set on production
Note 1 to entry: The “nominal set pressure” (P ) is often called “set pressure”.
nr
3.9
water tightness pressure
P
e
pressure up to which the expansion valve is closed
Note 1 to entry: See Figure 1.
3.10
initial opening pressure
P
dc
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
o
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
Pdn
pressure at which the discharged flow is above the limit
Note 1 to entry: See Figure 1 and Table 8.
3.13
closing pressure
P
f
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
4 Materials
4.1 General
NOTE Health and quality requirements in accordance with European and national legislation for final materials
in contact with water intended for human consumption are not covered by this document.
4.2 Dezincification resistant copper alloy
Copper-zinc alloys containing more than 15 % zinc are subject to dezincification when submitted to
water capable of dezincification. In the countries where the use of products made of dezincification
resistant materials is required, the materials used shall guarantee a dezincification depth less than
200 μm in any direction. For this purpose, materials shall be tested in accordance with EN ISO 6509-1
and the product shall be marked in compliance with the indications according to Clause 14.
4.3 Surface coating
The outside and inside surfaces of the device can contain a coating. Such coating shall not impair the
functional characteristics of the device.
Only for materials with inadequate corrosion resistance (e.g. iron steel) the corrosion resistance test in
4.4.2 shall be determined.
4.4 Corrosion
4.4.1 General
The applied materials shall be corrosion resistant or protected against corrosion. The materials used shall
not have an adverse effect on each other.
Only for materials with inadequate corrosion resistance (e.g. iron steel) the corrosion resistance test in
4.4.2 shall be determined.
4.4.2 Corrosion resistance test
4.4.2.1 General
The purpose of the corrosion resistance test is to qualify all used materials of the external part of the
product. The whole device shall be tested, not only the parts in contact with potable water.
4.4.2.2 Procedure
Samples shall be prepared for the corrosion resistance test as described as follows.
Carry out the test in accordance with the neutral saline-spray test of EN ISO 9227 and the following:
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.
c) After treatment and before visual examination, rinse the test samples in water to remove any salt
residue.
4.4.2.3 Requirements
The device shall comply with the requirements as included in cold water pressure test (10.3.2). The
results shall not deviate by more than 10 % from the original values.
4.5 Detection of residual stress
4.5.1 General
This test shall be performed for devices which have bodies made out of brass materials and with female
threads according to EN 10226-1 and compression ends according to EN 1254-2.
4.5.2 Principle
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 4.5.3 b)).
The test entails exposing test specimens consisting of the assembled device in an atmosphere loaded with
ammonia vapour.
4.5.3 Procedure
This subclause integrates elements of 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:
a) 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:
a) Rinse the test specimens with a clean non-chlorinated solvent (for example, ethanol).
b) Let it dry in the air.
c) 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.
d) 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.
e) 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.
+2
f) After an exposure of ( 24 ) h, remove the test specimens and rinse them.
4.5.4 Requirements
After the test, the body of the device shall be inspected visually for stress corrosion cracking. No cracking
shall occur.
At least two samples shall be in accordance with the test in 10.3.2.
5 Compatibility of the expansion group with disinfection
5.1 General
The disinfection test is carried out to ensure that a device can continue to fulfil its function after several
curative disinfection measures (shock disinfection) in a drinking water installation (see Table 2).
NOTE See Annex C.
5.2 Requirements
The entire device shall remain functional after carrying out the disinfection test with one of the three
disinfectant solutions (Table 2).
The device shall comply with th
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