EN 61770:2009/A11:2018

Electric appliances connected to the water mains - Avoidance of backsiphonage and failure of hose-sets

2020-08-17: D166/C049 - extension of DOW approved to read 2021-11-18 (instead of 2021-05-18).
2018-03-01: BT approved addition of A-deviation for GB before publication D159/C013.
2021: CLC legacy converted by DCLab NISOSTS

Elektrische Geräte zum Anschluss an die Wasserversorgungsanlage - Vermeidung von Rücksaugung und des Versagens von Schlauchsätzen

Appareils électriques raccordés au réseau d'alimentation en eau - Exigences pour éviter le retour d'eau par siphonnage et la défaillance des ensembles de raccordement

Električne naprave, priključene na vodovod - Preprečevanje povratnega vodnega udara in odpovedi cevnega sestava - Dopolnilo A11

Ta mednarodni standard določa zahteve za naprave za gospodinjska in podobna opravila za preprečevanje povratnega vodnega udara nepitne vode v vodovod. Določa tudi zahteve za cevne sestave, ki se uporabljajo za povezovanje takih naprav z vodovodom, ki dovaja vodo pod tlakom, ki ne presega 1 MPa.

General Information

• Status: Published
• Publication Date: 17-May-2018
• Withdrawal Date: 17-Nov-2021
• ICS: 97.040 - Kitchen equipment
• ICS: 97.060 - Laundry appliances
• Technical Committee: CLC/TC 61 - Safety of household and similar electrical appliances
• Drafting Committee: CLC/TC 61 - Safety of household and similar electrical appliances
• Current Stage: 6060 - Document made available - Publishing
• Start Date: 18-May-2018
• Due Date: 15-Mar-2017
• Completion Date: 18-May-2018
• Directive: 2006/95/EC - Directive 2006/95/EC of the European Parliament and of the Council of 12 December 2006 on the harmonisation of the laws of Member States relating to electrical equipment designed for use within certain voltage limits (codified version)
• Directive: 2014/35/EU - Directive 2014/35/EU of the European Parliament and of the Council of 26 February 2014 on the harmonisation of the laws of the Member States relating to the making available on the market of electrical equipment designed for use within certain voltage limits
• Mandate: M/511 - Mandate to CEN, CENELEC and ETSI relating to harmonised standards in the field of the Low Voltage Directive
• Ref Project: SIST EN 61770:2009/A11:2018 - Electric appliances connected to the water mains - Avoidance of backsiphonage and failure of hose-sets

Relations

• Amends: EN 61770:2009 - Electric appliances connected to the water mains - Avoidance of backsiphonage and failure of hose-sets
• Effective Date: 28-Jan-2023

Overview

EN 61770:2009/A11:2018 (CLC) is a CENELEC amendment that updates safety requirements for electric appliances connected to the water mains to prevent backsiphonage and failure of hose-sets. It applies to household and similar electrical appliances (e.g., washing machines, dishwashers) supplied by water mains at pressures up to 1 MPa. The amendment aligns appliance requirements with the EN 1717 approach for evaluating backflow risk categories and specifying suitable backflow prevention devices.

Key topics and technical requirements

• Scope and exclusions: Covers household and similar appliances; excludes dry-cleaning appliances, medical and industrial appliances, integral water heaters/coolers and general-purpose backflow devices.
• Backflow prevention requirement: Appliances must be fitted with an appropriate backflow prevention device. Components that could pollute potable water (dispensers for chemicals etc.) must not be located upstream of the device.
• Hose-sets: Backflow devices may be integrated in hose-sets but the connection to the appliance must be permanently fixed and non-detachable without irreversible damage.
• Materials: Materials in contact with drinking water must not affect water quality and must comply with national regulations for potable water contact.
• Definitions and device types: Introduces and clarifies terms such as airgap (AA, AB, AF, AG), pipe interrupter, anti-pollution check valve, anti-vacuum valve, and reduced pressure zone backflow preventer.
• Airgap dimensions and overflow: Specifies airgap dimension rules (e.g., distance A ≥ 2D and never less than 20 mm; AF/AG circular overflow sizing) and overflow arrangement requirements for different fluid categories and nominal velocities (≤ 3 m/s).
• Testing and compliance: Devices are tested as installed under normal and fault conditions (ambient 20 °C ± 5 °C). Components already certified to relevant EN product standards need not be retested for functionality/endurance.

Practical applications - who uses this standard

• Appliance manufacturers (washing machines, dishwashers, water-dispensing appliances) for product design and compliance.
• Hose-set and backflow device producers integrating certified protection into assemblies.
• Test laboratories and certification bodies carrying out conformity assessment and Type tests.
• Installers, specifiers, and water utilities ensuring correct installation, protection points and avoidance of potable water contamination.
• Regulatory and conformity assessment professionals referencing CLC/CENELEC rules.

Related standards and references

• EN 61770:2009 (base standard)
• EN 1717 (approach to risk categories and backflow prevention)
• EN 60335-2 series (appliance safety parts)
• Relevant national regulations for materials in contact with drinking water

Keywords: EN 61770:2009/A11:2018, backflow prevention, backsiphonage, hose-sets, airgap, water mains, electric appliances, CLC, CENELEC.

Standards Content (Sample)

SLOVENSKI STANDARD
01-oktober-2018
(OHNWULþQHQDSUDYHSULNOMXþHQHQDYRGRYRG3UHSUHþHYDQMHSRYUDWQHJDYRGQHJD
XGDUDLQRGSRYHGLFHYQHJDVHVWDYD'RSROQLOR$
Electric appliances connected to the water mains - Avoidance of backsiphonage and
failure of hose-sets
Elektrische Geräte zum Anschluss an die Wasserversorgungsanlage - Vermeidung von
Rücksaugung und des Versagens von Schlauchsätzen
Appareils électriques raccordés au réseau d'alimentation en eau - Exigences pour éviter
le retour d'eau par siphonnage et la défaillance des ensembles de raccordement
Ta slovenski standard je istoveten z: EN 61770:2009/A11:2018
ICS:
91.140.60 Sistemi za oskrbo z vodo Water supply systems
97.030 (OHNWULþQLDSDUDWL]DGRPQD Domestic electrical
VSORãQR appliances in general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN 61770:2009/A11

NORME EUROPÉENNE
EUROPÄISCHE NORM
May 2018
ICS 97.040; 97.060
English Version
Electric appliances connected to the water mains - Avoidance of
backsiphonage and failure of hose-sets
Appareils électriques raccordés au réseau d'alimentation en Elektrische Geräte zum Anschluss an die
eau - Exigences pour éviter le retour d'eau par siphonnage Wasserversorgungsanlage - Vermeidung von Rücksaugung
et la défaillance des ensembles de raccordement und des Versagens von Schlauchsätzen
This amendment A11 modifies the European Standard EN 61770:2009; it was approved by CENELEC on 2017-12-25. CENELEC members
are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this amendment 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 CENELEC member.
This amendment exists in three official versions (English, French, German). A version in any other language made by translation under the
responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the same status as
the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden,
Switzerland, Turkey and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2018 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN 61770:2009/A11:2018 E

European foreword
This document (EN 61770:2009/A11:2018) has been prepared by CLC/TC 61 "Safety of household and
similar electrical appliances" in collaboration with CEN/TC 164 “Water Supply”.
It was generated to overcome occurring uncertainties in checking the appliances since extension of the
scope for all EN 60335-2 parts having the necessity to be connected to the water mains.
Significant changes are the adoption of the EN 1717 approach of evaluating the risk categories and
providing provisions / backflow prevention devices to realise prevention against the evaluated risks and to
offer a choice of relevant backflow prevention devices which are already described by separate EN-
Standards but with easing the requirements at points, where definitions which are not safety-relevant for
the use in Electrical Appliances connected to the water mains prohibit industrialised realisation. Examples
are requirements regarding size, stability and markings which are well-grounded for the use in house
installation, but not for the realisation inside an electric appliance.
The following dates are fixed:
• latest date by which this document has
(dop) 2018-11-18
to be implemented at national level by
publication of an identical national
standard or by endorsement
• latest date by which the national
(dow) 2021-05-18
standards conflicting with this
document have to be withdrawn
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
This amendment supplements or modifies the corresponding clauses of EN 61770:2009.
There are no special national conditions causing a deviation from this amendment.
There are no national deviations from this amendment.
Clauses, subclauses, notes, tables, figures and annexes which are additional to those in IEC 61770:2008
are prefixed “Z”.
1 Scope
Replacement:
This European Standard specifies requirements for appliances for household and similar purposes to
prevent the backflow of non-potable water into the water mains. It also specifies requirements for hose
sets used for connecting such appliances to the water mains that supply water at a pressure not
exceeding 1 MPa.
NOTE 1 Examples of similar purposes are the installation of appliances in canteens, restaurants, launderettes and
communal flats.
NOTE 2 The connection of the appliance to the water mains may be temporary or permanent.
NOTE 3 When reference is made to the water mains, water supplied from a cistern or similar system is also included.
This standard does not apply to
a) appliances used for dry cleaning;
b) appliances for medical purposes;
c) appliances intended for industrial purposes;
d) water heaters that are an integral part of the water supply system;
e) water coolers that are an integral part of the water supply system;
f) backflow prevention devices for general purposes.
3 Terms and definitions
3.3 Delete the NOTE.
Replace 3.4 by the following:
3.4
airgaps
3.4.Z1
airgap (general)
backflow prevention device with unobstructed free distance between the water inlet or the end of the feed
pipe and the critical water level
3.4.Z2
airgap AA
visible unobstructed and complete air gap placed permanently and vertically between the lowest point of
the inlet feed orifice and any surface of the receiving vessel that determines the maximum water level at
which the device overflows
3.4.Z3
airgap AB
permanent and vertical distance between the lowest point of the inlet orifice and the critical water level
and having a non-circular overflow
3.4.Z4
airgap AD
horizontal and permanent distance between upstream feed orifice and downstream receiving orifice
3.4.Z5
airgap AF
permanent and vertical distance between the lowest point of the inlet orifice and the critical water level or
the top of the overflow having a circular overflow
3.4.Z6
airgap AG
permanent and vertical distance between the lowest point of the inlet orifice and the critical water level
having an overflow capable of draining the maximum inflow of water under fault condition

Replace 3.6 by the following:
3.6 Void
Add the following new definitions after 3.6:
3.6.Z1
pipe interrupter with movable parts
backflow prevention device having air inlets which are generally open to the atmosphere in no flow
conditions and air inlets are closed at a measurable water flow rate through the device
3.6.Z2
dynamic air inlet device
device to prevent pollution by backflow equipped with at least one obturator that opens the air inlet(s) to
atmosphere in case of vacuum at the feed orifice
Note 1 to entry: In some related IEC standards this device may be called ”dynamic backflow preventer“.

Add the following new definitions:
3.Z1
anti-pollution check valve
single safety device, consisting of one closing element, which permits flow in one direction only and
opens automatically when the pressure in the direction of flow upstream the valve is greater than the
pressure downstream
3.Z2
anti-vacuum valve
safety device which provides protection against backsiphonage by opening air inlets to the atmosphere
3.Z3
backflow preventer with reduced pressure zone
safety device which artificially provides disconnection by the action or the reaction of one or more
hydromechanical closing and venting devices activated by pressure differences
Note 1 to entry: Device which uses reduced intermediate pressure zone for action.
3.Z4
combination of protection devices
series combination of an anti-pollution check valve and an anti-vacuum valve respectively located in
downstream direction
3.Z5
protection point
location in a hydraulic circuit where a backflow prevention device is installed
3.Z6
diameter of feed pipe (bore D)
maximum internal diameter (or calculated from the equivalent cross sectional area) found within the last
metre of the supply pipe to the backflow prevention device or the DN of the inlet connection
Note 1 to entry: The dimension of the diameter “D” is in mm.
3.Z7
non-controllable anti-pollution double-check valve
mechanical protection device, equipped with two independent acting anti-pollution check valves, to permit
flow in one direction only
3.Z8
flow pressure
gauge pressure at a measuring point in the system under flow condition
4 General requirements
Add the following new subclause before 4.1:
4.Z1 All materials coming into contact with water intended for human consumption shall present neither
health risk nor cause any change of the drinking water in terms of quality, appearance, smell or taste.
Products intended for use in drinking water supply systems shall comply, when existing, with national
regulations and testing arrangements that ensure fitness for contact with drinking water.
NOTE Many countries have requirements concerning the prevention of contamination of potable water as a
result of contact with unsuitable materials upstream of a backflow prevention device.
4.1 Replace the text by the following:
Appliances shall be provided with a backflow prevention device.
Components presenting a potable water hazard, such as dispensers for adding cleaning, rinsing,
softening or similar agents to the water, shall not be located upstream of the backflow prevention device.
Pipework containing potable water located upstream of a backflow prevention device shall not pass
through non-potable water in the appliance.
An appliance connected to a water main may have several safety devices. Every safety device shall be
able to protect against the risk for which it is foreseen (see Annex ZA). If a common protection to several
protection points is sought, it is necessary to consider the technical parameter presenting the highest
risk value in the most unfavourable fluid category to all associated parts of the appliance.
Compliance is checked by inspection.
NOTE For a given point in a hydraulic system, "upstream" indicates the side from which the water flows and
"downstream" indicates the side to which the water flows.
4.2 Replace the text by the following:
Suitable backflow prevention devices shall be incorporated in, or fixed to the appliance or they shall be
integrated in a hose set.
If the backflow prevention device is integrated in the hose set then the connection to the appliance shall
be fixed permanently and not be detachable without any irreversible damage.
Backflow prevention devices shall be constructed so that
– their functional characteristics cannot be changed, even intentionally;
– they can only be removed with the aid of a tool;
– if omitted, the appliance is rendered inoperable or manifestly incomplete;
– its selection of the necessary safety level is in compliance with Annex ZA.
Compliance is checked by inspection.
5 General conditions for the tests
5.1 Title the subclause as “5.1 Normal conditions”
rd
3 dashed item: replace “dynamic pressure” by “flow pressure”
Add the following “NOTE Z1”:
NOTE Z1 Components or products previously being tested and shown to comply with the relevant product standard
need not be re-tested on functionality and endurance.
5.2 Title the subclause as: “5.2 Fault conditions”
5.3 Title the subclause as “5.3 Tests”
Replace in the first dashed item “pipe interrupters and dynamic backflow preventers” by “backflow
prevention devices”.
Replace subclause 5.4 by the following:
5.4 Tests on backflow prevention devices
Backflow prevention devices are tested as installed, unless this is impracticable or is otherwise
specified.
Components that have not been separately tested and found to comply with the relevant EN product
standard and components that are not marked or not used in accordance with their marking are tested in
accordance with the conditions occurring in the appliance. The number of samples being that required by
the relevant EN product standard.
When determining the critical water level of appliances having more than one water inlet, and a
programme permitting simultaneous filling, each water inlet is closed in turn, other water inlets being
open.
Unless otherwise specified, the tests are carried out at an ambient temperature of 20 °C ± 5 °C.
Replace 5.5 and 5.6 by the following:
5.5 Void.
5.6 Void.
6 Airgaps
Replace the text by the following:
6 Airgaps
6.Z1 General
This clause specifies the characteristics and the requirements of air gaps for fluid category of risk 3, 4
and 5 for nominal flow velocity not exceeding 3 m/s.
6.Z2 Overflow arrangements
All overflow arrangements subsequently connected to a drain shall meet the requirements as detailed in
ZA.5.
6.Z2.1 AB air gap overflow
Shall be of non-circular design, shall discharge immediately into free air and shall be totally unobstructed.
The height of the overflow arrangement Oω is ≥ 2D + h and never less than 20 mm (see Figure Z2,
Figure Z3 and Figure Z4).
6.Z2.2 AF air gap overflow
Shall be of circular design having a minimum cross sectional area throughout its length equal to four
times the cross sectional area of the feed pipe (D) (see Figure Z6)
6.Z2.3 AG air gap overflow
Shall be of circular design having a minimum internal diameter of 19 mm throughout its length (see Figure
Z7).
6.Z3 Requirements
6.Z3.1 Water inlet device
Every water inlet device and its pipework shall be securely and rigidly fixed to prevent moving or bending
in order to maintain the air gap.
The water feed pipe, inlet device and its outlet shall not come into contact in any way with a fluid from
downstream of the airgap.
For air gaps AA the direction of flow shall be downward and not be more than 15° from the vertical.
6.Z3.2 Backflow/back pressure
If the receiving vessel can be subject to positive pressure backflow, the inlet orifice shall be positioned so
that the ascending/returning backflow fluid cannot contaminate it.
When the air gap is part of an installation which can generate positive pressure backflow, a means of
limiting the flow rate to a rate which shall not compromise the overflow arrangement is incorporated, i.e.
non-return valve fitted upstream of the pressurisation unit.
For multiple water inlets, potable water inlets shall terminate at a higher level than non-potable water
inlets (fluid category 5) and never closer than 2 D measured horizontally and vertically downward.
6.Z4 Characteristics
6.Z4.1 Air gap AA
Key
A Air gap
H Maximum level
D Internal diameter of feed pipe (bore)
1 Feed pipe
2 Feed orifice
3 Receiving vessel
4 Spillover level
5 15° maximum from the vertical
Figure Z1 — Dimensions air gap AA

6.Z4.1.1 Single supply
In the case of a single supply pipe to a single vessel having a continuous, unobstructed overflow around
the top, the distance A, shall not be less than the value A ≥2D but not less than 20 mm. (see Figure Z1).
6.Z4.1.2 Multiple supplies
In the case of multiple feed pipes to a single vessel having a continuous unobstructed overflow around
the spillover, the distance A, shall not be less than the value A ≥2 times the total sum of all inlet bore
diameters (D), but not less than 20 mm.
6.Z4.1.3 Vessels with variable height rim
Vessels having a variable height rim can be assessed against this standard only if they can be tested in a
maximum positive fault condition, and the air gap between the maximum level and the inlet device outlet
can be maintained. The maximum level is determined by measurement of the depth of water above the
spillover level, with the inflow with all feed pipes discharging at an individual inflow calculated at Q =
0,14D in litres per minute, or a flow pressure of 1 MPa (10 bar) if flow rate(s) Q cannot be achieved.
Where D is the bore of the feed pipe and with all outlets including optional warning pipes closed, based
on a velocity of 3 m/s or the maximum recommended flowrate for manufactured appliances when the flow
rate is higher than Q.
6.Z4.2 Air gap AB
Key
A Air gap (distance)
D Internal diameter of feed pipe (bore)
H Maximum level
1 Feed pipe
2 Feed orifice
3 Receiving vessel
4 Spillover level
5 Optional warning pipe
6 Uw ≥ 5h
7 Critical water level (distance h)
Figure Z2 — Dimensions Air gap AB

Key
1 Cw≤ 5h
2 Ow≥ 2D+ h and never less than 20 mm
l l≥ 10h
Figure Z3 — Rectangular overflow arrangement
Key
1 Cw≤ 5h
2 and never less than 20 mm
Ow≥ 2D+ h
l
l≥ 10h
Figure Z4 — Letterbox overflow arrangement

6.Z4.2.1 Single supply
For air gaps AB the critical water level (h) shall be established and the air gap distance A measured
from the lowest point of the water inlet to the critical water level (see Figure Z2).
The distance A is ≥ 2D and not less than 20 mm and h is determined either by:
a) Test, by determining the measurement of the depth of water above the spillover level of the overflow
arrangement, 2 s after the inflow equal to Q = 0,14D in litres per minute has stopped or a flow
pressure of 1 MPa (10 bar) has stopped if the flow rate Q cannot be achieved, where D is the bore of
the inlet, and with all outlets including optional warning pipe (except the overflow arrangement)
closed, based on velocity of 3 m/s, or the maximum recommended flow rate for manufactured
appliances, when the flow rate is higher than Q.
or by:
b) Calculation, by determining the depth of water above the spillover level of the overflow arrangement
using the following equation:
 
10 × Q
 
h=
 
3,143× l
 
where
Q is the inflow in litres per minute at 3 m/s (Q = 0,14 D );
l is the width of the overflow arrangement in millimetres.The calculation is only valid where:
– width (l) is greater than or equal to 10 h at the spillover level;
– crest thickness of the overflow arrangement (Cw) is less than or equal to 5 h;
– upstream face of the overflow arrangement (Uw) is vertical to a depth greater than or equal to 5 h;
– the depth of the overflow arrangement or notch (Ow) is greater than or equal to 2D+h and never
less than 20 mm.
When the overflow is not rectangular in design it shall satisfy air gap dimension A by test detailed above.
6.Z4.2.2 Multiple supplies
In the case of multiple feed pipes to a single vessel having a non-circular unrestricted overflow, the
distance of the air gaps for the potable water supply shall be dimension A above the critical water
level. The critical water level shall be determined 2 s after stopping the inflow with all feed pipes
discharging at an individual inflow calculated at Q = 0,14D in litres per minute. If the flow rate Q cannot
be achieved, apply a flow pressure of 1 MPa (10 bar) on all inlets. No feed orifice shall be less than
distance A above the critical water level. For calculating air gap distance A, use A= 2 D
∑
6.Z4.3 Air gap AD
The receiving vessel shall be so positioned that wasted water is kept to an absolute minimum
and to ensure that any water returning due to the maximum possible positive pressure backflow
does not come into contact with the upstream feed orifice.
The airgap distance is the horizontal distance between the terminal end of the upstream orifice
(injector) and the inlet end of the downstream receiving orifice. The distance, A, shall not be less
than the value A ≥2D but not less than 20 mm (see Figure Z5).

Key
A Air gap
1 injector
2 Receiving vessel
3 Upstream feed orifice (D)
4 Downstream receiving orifice
5 Air break to drain
Figure Z5 — Dimensions Air gap AD
The air break to drain shall be capable of draining off the maximum flow rate without contacting
the inlet device(injector(s)), with all injectors discharging with an individual flowrate of
Q = 0,14 D l/min. or, a flow pressure of 1 MPa (10 bar) if the flow rate Q cannot be achieved
when the receiving vessel feed pipes are closed
6.Z4.4 Air gap AF
Key
1 Feed pipe
2 Feed orifice
3 Receiving vessel
4 Spillover level
5 Critical level (distance h)
6 Overflow pipe
7 Air break to drain
A Air gap (distance)
D Internal diameter of feed pipe (bore)
H Maximum level
Figure Z6 — Dimensions Air gap AF

6.Z4.4.1 Single supply
For air gaps AF the critical water level (h) shall be established and the air gap distance 'A' measured
from the lowest point of the water inlet to the critical water level (see Figure Z6).
The air gap distance A shall be ≥ 2 D and never less than 20 mm and h is determined either by:
a) Test, by determining the measurement of the depth of water above the spillover level of the overflow
arrangement 2 s after the inflow equal to Q = 0,14 D in l/min has stopped or a flow pressure of 1
MPa (10 bar) has stopped if the flow rate Q cannot be achieved, where D is the inlet bore and with
all outlets (except the overflow) closed, based on a velocity of 3 m/s, or the maximum recommended
flow rate for manufactured appliances when the flow rate is higher than Q;
or by:
b) Measurement of the air gap distance 'A' from the lowest point of the water inlet device and the
uppermost point of the overflow outlet bore.
6.Z4.4.2 Multiple supplies
In the case of multiple feed pipes to a single vessel having a circular unrestricted overflow, the distance
of the air gaps for the potable water supply shall be dimension 'A' above the critical water level. The
critical water level shall be determined with all feed pipes discharging at an individual inflow calculated
at Q = 0,14 D .
If the flow rate Q cannot be achieved, apply flow pressure of 1 MPa (10 bar) on all inlets. No feed orifice
shall be less than distance 'A' above the critical water level. After calculations the distance A shall not
be less than 20 mm.
For calculating air gap distance 'A' use A= 2⋅ D
∑
6.Z4.5 Air gap AG
Key
1 Feed pipe
2 Feed orifice
3 Receiving vessel
4 Spillover level
5 Critical level (distance h)
6 Overflow pipe
7 Air break to drain
A Air gap (distance)
D Internal diameter of feed pipe (bore)
H Maximum level
Figure Z7 — Dimensions Air gap AG

6.Z4.5.1 Single supply
For air gaps AG the critical water level (h) shall be established and the air gap distance 'A' measured
from the lowest point of the water inlet to the critical water level (see Figure Z7). For air gap distances
see Table Z1.
The air gap distance A shall be as shown in Table Z1 and can be determined either by measuring h by
test or for ≤ DN 15 by measuring the air gap distance A:
a. Test, by determining the measurement of the depth of water above the spillover level of the overflow
2 s after the inflow equal to Q = 0,14 D in l/min has stopped or, a flow pressure of 1 MPa (10 bar)
has stopped if the flow rate Q cannot be achieved. Where D is the inlet bore (see 3.Z6) and with all
outlets (except the overflow) closed, based on a velocity of 3 m/s, or the maximum recommended
flow rate for manufactured appliances when the flow rate is higher than Q;
Or by
b. Measurement, in the case of a pipe or valve not greater in size than 15 mm (G½), by measurement of
the air gap distance 'A' from the lowest point of the feed orifice and the centre line of the overflow
pipe.
Table Z1 — Air gap distance
Pipe/valve size Distance A
(inch/metric) (mm)
≤ DN 15 (G ½) ≥ 20 mm
≤ DN 20 (G ¾) ≥ 25 mm
2 × D
> DN 22 (G ¾)
6.Z4.5.2 Multiple supplies
In the case of multiple feed pipes to a single vessel having an overflow, the distance of the air gaps for
the potable water supply shall be dimension 'A' above the critical water level (h). The critical water
level (h) shall be determined with all feed pipes discharging at an individual inflow calculated at Q = 0,14
D .
If the flow rate Q cannot be achieved, apply a flow pressure of 1 MPa (10 bar) on all inlets. No feed orifice
shall be less than distance 'A' above the critical water level.
For calculating air gap distance 'A' use
A= 2⋅ D
∑
6.Z5 Verification
6.Z5.1 Air gap AB
Verification can be achieved by test or by calculation.
Procedure for verification by Test, see 6.Z4.2.1 a).
Sequence of test
– Close all outlets (except the overflow);
– Identify D;
– Calculate Q;
– Apply flow rate Q and maintain maximum water level;
– Note contact with inlet device(s) during filling and at maximum level;
– Stop flow rate Q;
– After 2 s establish distance h;
– Measure air gap distance A between distance h and the lowest point of the feed orifice.
Requirements
– No contact between the downstream fluid and the inlet device(s);
– The height Ow shall be ≥ 2D + h and never less than 20 mm.
– The air gap distance A shall be ≥ 2D and never less than 20 mm.
Procedures for verification by calculation, see 6.Z4.2.1 b)
6.Z5.2 Air gap AD
Verification can be achieved by test and by measurement.
Procedure for verification by measurement of air gap ‘A’:
Sequence of test
– measure diameter 'D';
– measure air gap ‘A’;
Requirements
– the air gap distance A shall be ≥ 2 D and never less than 20 mm.
Procedure for verification of air gap distance ‘A’ during backflow
(This test only applies to situations where the receiving vessel is mounted higher than the air
gap.)
Sequence
– close all outlets;
– fill the downstream receiving vessel to its maximum;
– individually test each air gap by opening each outlet;
– note any contact with the upstream inlet orifice.

Requirements
– no contact is permitted between the backflowing water and the upstream inlet orifice.

Procedure for verification by test of air break to drain
Sequence
– close all outlets;
– measure diameter 'D';
– calculate 'Q';
– apply flowrate(s) 'Q';
– stop flowrates 'Q';
– after 2 s note contact with the draining water level and air inlet(s)

Requirement
– no contact is permissible between the draining water level and the outlet orifices.

6.Z5.3 Air gap AF
Verification can be achieved by test or by measurement.
Procedure for verification by test, see 6.Z4.4.1 a)
Sequence of test
– close all outlets (except the overflow);
– identify 'D';
– calculate Q;
– apply flow rate Q and maintain maximum water level;
– note contact with inlet device(s) during filling and at the maximum level;
– stop flow rate Q;
– after 2 s establish distance h;
– measure air gap distance A between distance h and lowest point of the feed orifice.
Requirements
– no contact between the downstream fluid and the inlet device(s);
– the air gap distance A shall be ≥ 2 D and never less than 20 mm.
Procedure for verification by measurement (single supply only)
Sequence of measurement, see 6.Z4.4.1 b)
Requirements
– the measured air gap shall meet the requirements of dimension ’A’.
6Z.5.4 Air gap AG
Verification can be achieved by test or by measurement.
Procedure for verification by test see 6Z.4.5.1 (a)
Sequence of test
 close all outlets (except the overflow);
 identify 'D';
 calculate Q;
 apply flow rate Q and maintain maximum water level;
 note contact with the outlet of the inlet device(s) during filling and the maximum level;
 stop flow rate Q;
 after 2 s establish distance h;
 measure air gap between distance h and lowest point of the feed orifice.
Requirements:
 no contact between the receiving vessel fluid and the outlet of the inlet device(s);
 measured air gap shall meet the requirements of dimension 'A' (see Table Z1).

Procedure for verification by measurement (single supply only ≤ DN 15)
Sequence of measurement
 Verify that the single supply is ≤ DN 15
 see 6.Z4.5.1 (b).
Requirements
 measured air gap shall meet the requirements of dimension 'A' (see Table Z1).

7 Pipe interrupters
Replace the whole Clause 7 by the following:
7.Z1 Pipe interrupter without movable parts
7.Z1.1 Pipe interrupters shall be constructed so that the air-inlet openings remain permanently free and
open to the atmosphere. Water which may leak in normal use from an air-inlet opening shall flow into the
container of the appliance but shall not reach a sufficient level for the vertical dimensions to be reduced
below those specified in 7.Z1.3 and 7.Z1.4.
Pipe interrupters shall be protected against deliberate obstruction or manipulation which could affect the
results of the tests.
Downstream of the pipe interrupter no closing element shall be mounted.
The total cross-sectional area of the air-inlet openings shall not be less than the cross-sectional area of
the water-inlet opening. The smallest dimension of each air-inlet opening shall be at least 3 mm. The
dimensions are measured at right angles to the direction of the airflow.
Compliance is checked by inspection, by measurement and by the tests and measurements of 7.Z1.2 to
7.Z1.4. However, if the measurements of 7.Z1.3 and 7.Z1.4 cannot be made due to the construction of
the appliance, compliance is checked by the test of A.1
7.Z1.2 For pipe interrupters, a vertical tube of glass or other transparent material having
approximately the same internal diameter and a length of at least 500 mm, is connected to the outlet of
the pipe interrupter. The free end of the tube is immersed in water to a depth of at least 25 mm, as
shown in Figure 1.
A vacuum pump is connected directly to the inlet of the pipe interrupter and a negative pressure of
65 kPa ± 15 kPa is applied for at least 5 s. The distance h between the water level in the tube and the
water level in the container is measured.
For pipe interrupters which are incorporated in the appliance downstream of a magnetic valve, the test
is carried out in the appliance. The vacuum pump is connected directly to the water inlet of the appliance
by means of the shortest possible length of tube.
The cross-sectional area of the connection of the vacuum pump shall be sufficient so that the airflow is
not restricted.
NOTE Z1 If the inlet hose cannot be removed even with the aid of a tool, the vacuum pump is connected to the inlet
of the hose.
7.Z1.3 The appliance is operated under fault conditions, until the maximum water level is reached.
The vertical distance between the maximum water level and the lowest rim of the air-inlet opening of the
pipe interrupter is measured. It shall be at least equal to dimension h, shown in Figure 2.
7.Z1.4 Immediately after the test of 7.Z1.3, the water inlet is closed. The vertical distance between the
critical water level and the lowest rim of the air inlet opening is measured. It shall be at least equal to h +
20 mm.
The critical water level in the hoses connecting the pipe interrupter to a water softener downstream of
a dynamic air inlet device is also checked.
NOTE Z1 If the critical water level cannot be observed due to an opaque part or hose, this part or hose is
replaced by a transparent part or transparent hose having the same shape and dimensions.
7.Z2 Pipe interrupter with movable parts
7.Z2.1 Pipe interrupters with movable parts are safety devices with air inlets, which are sealed, when
water at a pressure higher than atmospheric pressure pass it, but the air inlets are open to admit air if the
water flow stops or if there is a sub atmospheric pressure at the water inlet.
Pipe interrupters with movable parts shall be protected against deliberate obstruction or manipulation
which could affect the results of the tests.
The total cross-sectional area of the air-inlet openings shall not be less than the cross-sectional area of
the water-inlet opening. The smallest dimension of each air-inlet opening shall be at least 4 mm. The
dimensions are measured at right angles to the direction of the airflow.
Pipe interrupters with movable parts shall be installed at least 150 mm above the maximum water
level. There shall be no closing device downstream the pipe interrupters with movable parts.
Pipe interrupters with movable parts shall not be fitted with springs for supporting the tightness of the
device. In case of failure or damage of construction parts of the device the protection function of the
device shall not be disturbed.
Compliance is checked by the tests of 7.Z1.2 to 7.Z1.4.
7.Z2.2 Pipe interrupters with movable parts shall be able to resist a static pressure of 1,6 MPa
without the movable part being damaged.
Pipe interrupters with movable parts are to be installed into a test rig and are subjected to a static
pressure of 1,6 MPa for a duration of 10 min. There shall be no damage or permanent deformation
visible.
7.Z2.3 Pipe interrupters with movable parts shall not cause a backsiphonage at a vacuum of at least
50 kPa during 5 s.
Pipe interrupters with movable parts are to be installed into a test rig and are subjected to a vacuum of
at least 50 kPa during 5 s. There shall not occur backsiphonage, no damage or permanent deformation
shall be visible.
7.Z2.4 Pipe interrupters with movable parts shall not cause a backsiphonage with the movable part
removed from the device.
The first test of 7.Z1.2 is repeated. The distance h shall be approximately zero.
7.Z2.5 Pipe interrupters with movable parts shall have adequate mechanical strength and be
constructed to withstand such rough handling that may be expected in normal use.
Pipe interrupters with movable parts are to be installed into a hot water test rig having a temperature of
65 °C ± 2 °C. The appliance is operated at normal conditions. The flow rate through the device is
measured. For the test the device is subjected to a flow rate twice the measured value at 50 % duty cycle.
The cycle time is 12 s. Flow to no flow conditions and vice versa shall be provided within 1 s. The
endurance test has to be carried out for 80 000 cycles. After the test compliance is checked by repeating
7.Z2.3.
8 Dynamic backflow preventers
In the title, replace “Dynamic backflow preventers” by “Dynamic air inlet device”
8.1 Replace subclause 8.1 by the following:
Dynamic air inlet devices shall be constructed so that wear or damage of movable parts, their supports
or guides, or the removal of detachable parts does not allow backsiphonage. The movable parts shall
operate each time the water passes through the device under conditions of normal use.
Compliance is checked by inspection and by operating the dynamic air inlet device as described in 8.2,
followed by the test of Annex A.1.

8.2 Replace “dynamic backflow preventers” by “Dynamic air inlet devices” (4 times).
Add the following new subclause:
8.Z3 Examples of Dynamic air inlet devices

a) pressurized
b) after each cycle or in case of backsiphonage
Figure Z8 — Dynamic air inlet device with one obturator

a) pressurized
b) after each cycle or in case of backsiphonage
Figure Z9 — Dynamic air inlet device with two obturators

9 Hose-sets
Add before 9.1 the following new subclause:
9.Z1 Hose sets shall comply with
– this standard when separated by taps and fittings and are not part of the installation

-6”
9.1.9 Replace “0,5x10 by “(500 ± 50)ppb”

Figure 3 – Kinking test
Add the following text to the key:
P pressure
D hose diameter
Add the following new figures:

Key
1 water inlet
2 regulating valve
3 drain valve
4 regulating valve
5 transparent tube having a diameter of approx. 25 mm
6 anti-pollution check valve to be tested
7 transparent container
8 transparent tube having a diameter of approx. 12 mm
9 open outlet
Figure Z10 — Arrangement for verifying the water tightness and the opening pressure of
anti-pollution check valves
Key
1 static pressure at 1 MPa
2 water supplied at a flow rate of 2 m/s
3 free outlet
4 free outlet
5 anti-pollution check valve
6 changeover valve
Figure Z11 — Arrangement for the endurance test on anti-pollution check valves
Key
1 water inlet
2 regulating valve
3 anti-vacuum valve to be tested
4 flexible transparent hose
Figure Z12 — Arrangement for verifying the durability of anti-vacuum valves

Key
1 water inlet
2 regulating valve
3 anti-vacuum valve to be tested
4 regulating valve
Figure Z13 — Arrangement for verifying the tightness of anti-vacuum valves at
overpressure
Key
1 water inlet
2 water inlet valve
3 device generating underpressure
4 regulating valve
5 anti-vacuum valve to be tested
6 transparent hose
7 container
Figure Z14 — Arrangement for verifying the opening pressure of anti-vacuum valves

Key
1 device generating under pressure
2 regulating valve
3 anti-vacuum valve to be tested
4 transparent hose
5 container
Figure Z15 — Arrangement for verifying anti-vacuum valves under vacuum conditions
Key
A flow rate  maximum pressure 0,3 MPa (3 bar) at zero-flow rate
B static pressure 1 MPa ± 0,05 MPa (10 bar ± 0,5 bar)
C static pressure 0,3 MPa ± 0,03 MPa (3 bar ± 0,3 bar)
P1 pressure gauge
6 regulating valve
7 valve with time control of opening and closing
Figure Z16 — Arrangement for the durability test on backflow preventers with reduced
pressure zone
Add the following new chapters:
Z1 Backflow preventer with reduced pressure zone
Z1.1 General
The settings of the action and difference pressure of the device shall be fixed and not adjustable.
Only the pressure of the water of the supply network can operate the control of the internal components
of the device.
Possible additional control devices (electric, pneumatic) shall not adversely affect the backflow protection
function.
The backflow preventer with reduced pressure zone shall be installed in such a way that the
discharge of the relief valve is in downward position.
The design of the relief valve operation shall be such that when the differential pressure over the
upstream check valve is less than 14 kPa (140 mbar) the relief valve shall be open to ensure positive
safety.
Any water retention shall not be possible within the intermediate zone.
The cross sections of the passage orifices and of the pilot tube for operation the relief device shall be
equal to or greater than 45 mm² with DN ≥15, or 12,5 mm with DN<15, no dimension for the calculation
of the cross section shall be less than 4 mm.
An air break to drain shall exist between any waste drain and any means of collecting the discharged
water.
The backflow preventer with reduced pressure zone with an air break to drain fitted shall evacuate the
full relief flow rate without spilling to the outside.
This air break to drain shall be directly incorporated into the backflow preventer with reduced pressure
zone.
The relief orifice of the device shall permit, neither the fitting of a standardized threaded pipe, nor the
connection of a standardized pipe or shape, be it by glue, welding or interlocking.
Z1.2 Verification of the pressure difference between the upstream and the intermediate
zones
For the following tests the manufacturer has to provide a special sample having the necessary test ports
to verify the function of the backflow preventer with reduced pressure zone.
Test ports have to be provided:
– upstream of the first check valve;
– in the intermediate zone;
– downstream of the second anti-pollution check valve.
Static test
Compliance is checked as follows:
– Record the pressure difference between upstream and intermediate zone over the upstream
pressure from 0,1 MPa to 1 MPa (1 bar to 10 bar).
– The pressure difference between the upstream zone and the intermediate zone shall be greater than
14 kPa (140 mbar).
Z1.3 Verification of the tightness of the downstream anti-pollution check valve (in the
closing direction)
Compliance is checked as follows:
– Downstream of the backflow preventer with reduced pressure zone, apply a pressure of 1,6 MPa
(16 bar) with water at 20°C, the upstream zone being at atmospheric pressure. The pressure is to be
applied in increments of 0,1 MPa (1 bar) per 5 s.
– Hold the pressure for 2 min.
– Isolate the backflow preventer with reduced pressure zone from the supply system for 10 min.
There shall be no leakage, no permanent deformation or deterioration of the downstream anti-pollution
check valve after the test.
Z1.4 Verification of the tightness of the upstream anti-pollution check valve at low
pressure
Compliance is checked as follows:
– Fill the backflow preventer with reduced pressure zone with water so that the water column has a
height of (200 ± 50) mm in the tube (diameter inside 10 + 0/-2 mm).
– Isolate for 5 min ± 30 s.
– Raise the level in the tube to (1000 ± 50) mm.
– Isolate for 5 min ± 30 s.
– Raise the level in the tube to (2000 ± 50) mm.
– Isolate for 5 min ± 30 s.
The tightness of the upstream check valve shall be verified by the water level in the tube which shall be
constant at each test stage.
No sagging of the water level in the tube shall be stated at each of the stages.
Z1.5 Verification of opening st
...