CEN/TC 164/WG 14 - Valves and fitting for buildings and devices to prevent pollution by backflow

This document specifies additional requirements to the product standards given in Clause 5 for valves and devices to prevent pollution by backflow of potable water with polymer parts and housings under internal pressure and without external loads intended for installations and equipment inside buildings conveying water for human consumption.

This document specifies:
- general construction, performance and material requirements for Frost Resistant Taps for outdoor use (FRT), PN 10.
- the application in the potable water installation with a static pressure of maximum 1,0 MPa (10 bar) and a distribution temperature of maximum 25 °C (PWC).
FRT valves shall consist of the 3 areas shown in Figure 1.
The conditions of use are according to the following Table 1.
The requirements with regard to the potable water quality are specified in national regulations.

This document specifies:
- general construction, performance and material requirements for Frost Resistant Taps for outdoor use (FRT), PN 10.
- the application in the potable water installation with a static pressure of maximum 1,0 MPa (10 bar) and a distribution temperature of maximum 25 °C (PWC).
FRT valves shall consist of the 3 areas shown in Figure 1.
The conditions of use are according to the following Table 1.
The requirements with regard to the potable water quality are specified in national regulations.

This document specifies the characteristics and the requirements of air gap with non-circular overflow (unrestricted) Family A, Type B for nominal flow velocity not exceeding 3 m/s. Air gaps are devices for protection of potable water in water installations from pollution by backflow. This document applies to air gaps in factory-assembled products and to constructed air gaps in situ and specifies requirements and methods to verify and ensure compliance with this document during normal working use.
The fluid in the receiving vessel is assumed to have similar properties to water. Where this is not the case, additional care or tests could be required to verify the efficacy of the solution in practical use.
The AB device is intended to be used in potable water installations according to EN 806 (all parts).

This document specifies the field of application, the dimensional, the physico-chemical, the design, the hydraulic, the mechanical, and the acoustic characteristics of controllable backflow preventers with reduced pressure zone, Family B, Type A.
This document covers controllable backflow preventers of Family B, Type A, with reduced pressure zones, intended to prevent pollution of potable water by backflow, caused by backsiphonage or by backpressure.
It is applicable to controllable backflow preventers in denominations DN 6 up to DN 250.
It covers controllable backflow preventers of PN 10 that are capable of working without modification or adjustment:
- at any pressure, up to 1 MPa (10 bar);
- with any pressure variation, up to 1 MPa (10 bar);
- in permanent duty at a limited temperature of 65 °C and for maximum 1 h at 90 °C.
It specifies also the test methods and requirements for verifying their characteristics, the marking and the presentation at delivery.

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).

This document specifies the dimensional, physical-chemical, design, hydraulic, mechanical and acoustic characteristics of mechanical disconnectors, direct actuated Family G, Type A.
This document is applicable to mechanical disconnectors in nominal sizes DN 8 up to DN 250, intended to prevent the return of water having lost its original sanitary and drinking qualities (called “polluted water” in this document), into the potable water distribution system whenever the pressure of the latter is temporarily lower than in the polluted circuit.
This document covers the mechanical disconnectors of PN 10 that are capable of working without modification or adjustment:
— at any pressure up to 1,0 MPa (10 bar);
— with any pressure variation up to 1,0 MPa (10 bar);
— in permanent duty at a limit temperature of 65 °C and 90 °C for 1 h maximum.
It specifies also the test methods and requirements for verifying these characteristics, the marking and the presentation at delivery.

This document specifies the dimensional, physical-chemical, design, hydraulic, mechanical and acoustic characteristics of mechanical disconnectors, flow actuated Family G, Type B.
This document is applicable to mechanical disconnectors flow actuated in nominal sizes DN 8 up to DN 250, intended to prevent the return of water having lost its original sanitary and drinking qualities (called “polluted water” in this document), into the potable water distribution system whenever the pressure of the latter is temporarily lower than in the polluted circuit.
This document covers the mechanical disconnectors of PN 10 that are capable of working without modification or adjustment:
— at any pressure up to 1,0 MPa (10 bar);
— in permanent duty at a limit temperature of 65 °C and 90 °C for 1 h maximum.
It specifies also the test methods and requirements for verifying these characteristics, the marking and the presentation at delivery.

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).

This document specifies the field of application, the dimensional, the physico-chemical, the design, the hydraulic, the mechanical, and the acoustic characteristics of in-line anti vacuum valve family D Type A.
This document covers in-line anti vacuum valve family D Type A, intended to prevent pollution of potable water by backflow, caused by backsiphoning only.
It is applicable to in-line anti vacuum valve in denominations DN 10 up to DN 50.
It covers in-line anti vacuum valve of PN 10 that are capable of working without modification or adjustment:
-   at any pressure, up to 1 MPa (10 bar);
-   with any pressure variation, up to 1 MPa (10 bar);
-   in permanent duty at a limited temperature of 65 °C and for maximum 1 h at 90 °C.
It specifies also the test methods and requirements for verifying their characteristics, the marking and the presentation at delivery.

This document specifies:
a)   the field of application;
b)   the requirements of hose union anti vacuum valves;
c)   dimensional and physio-chemical properties, and properties of general hydraulic, mechanical and acoustic design of hose union anti-vacuum valves of nominal sizes DN 15 up to and including DN 25;
d)   marking and technical product information.
This document specifies the characteristics of hose union anti-vacuum valves of nominal size DN 15 up to and including DN 25 that are suitable for use in drinking water systems at pressures up to and including 1 MPa (10 bar) and temperatures up to and including 65 °C and for 1 h at 90 °C.
HB protects against back siphonage only and is installed in vertical downward flow position.
HD protects against back flow and is installed in vertical downward flow position.
HB and HD anti-vacuum valves are for installation exclusively at the connecting point between stop valve and hose in vertical downward flow position.

This European Standard specifies dimensions, materials and performance requirements (including methods of test) for hydraulic safety groups, of nominal sizes from DN 15 to DN 25, having working pressures ) from 0,1 MPa (1 bar) to 0,7 MPa (7 bar). Hydraulic safety groups are intended for fitting to the potable water supply of storage water heaters, having a maximum storage temperature of 95°C.
Hydraulic safety groups limit the pressure in hot water heaters, prevent the backflow of water into the main circuit and prevent the discharged water to get into contact with the water in the water heater.
Hydraulic safety groups do not control the temperature. They ensure the hydraulic safety of water heaters if the mechanical resistance of the water heater remains at least equal to the rating pressure.
NOTE   The use of the device specified in this European Standard does not override the need to use controls (e.g. thermostats and cut-outs) which act directly on the power sources of water heaters.

This European Standard specifies dimensions, materials and performance requirements (including methods of test) for in line hot water supply tempering valves for sanitary hot water systems, of nominal sizes from DN 15 to DN 50. Tempering valves reduce the temperature of sanitary hot water for distribution throughout the hot water system. The conditions of use are specified in Table 1.
The valves are intended to be used with storage water heaters to provide tempered hot water to the terminal fitting. They are not intended to control the temperature at the point of use.
Tempering valves control the distribution temperature from a water heater to a preset value or an adjustable range, both between 45 °C and 65 °C.
Table 1 - Conditions of use

This document specifies:
a)   field of application;
b)   requirements for pressurised air inlet valves;
c)   dimensional and the physico-chemical properties and the properties of general hydraulic, mechanical and acoustic design of pressurised air inlet valves DN 15 to DN 50;
d)   test procedure and requirements for verifying these properties;
e)   marking and presentation;
f)   acoustics.
This document specifies the characteristics of pressurised air inlet valves DN 15 to DN 50 that are suitable for use in drinking water systems at pressures up to 1 MPa (10 bar) and temperatures up to 65 °C and for 1 h at 90 °C.

This European Standard specifies the characteristics and the requirements of air gaps with circular overflow (restricted) family A, type F for nominal flow velocity not exceeding 3 m/s. Air gaps are devices for protection of potable water in water installations from pollution. This document applies to air gaps in factory assembled products and to constructed air gaps in situ, and defines the physicochemical characteristics of materials of construction used for the purpose and application to ensure compliance with this document during normal working use.

This European Standard specifies the characteristics and the requirements of air gaps with overflow, family A, type G for nominal flow velocity not exceeding 3 m/s. Air gaps are devices for protection of potable water in water installations from pollution. This European Standard applies to air gaps in factory assembled products and to constructed air gaps in situ, and defines the physicochemical characteristics of materials of construction used for the purpose and application to ensure compliance with this document during normal working use.

This document specifies:
a)   field of application;
b)   requirements for automatic diverters;
c)   dimensional and the physico chemical properties and the properties of general hydraulic, mechanical and acoustic design of automatic diverters;
d)   test method and requirements for verifying these properties. For sanitary tapware (see Clause 2) with integrated devices, the automatic diverter is only considered to be a backflow protection device if it has passed the requirements of this document and additionally those of the applicable product standard for the draw off tap or mixing valve;
e)   marking and presentation;
f)   acoustics.
This document specifies the characteristics of automatic diverters suitable for use in drinking water systems at pressures up to 1 MPa (10 bar) and temperatures up to 65 °C and for 1 h at 90 °C. They are intended only for installation with no downstream closing device.
This document is applicable to the product type indicated as follows:
i)   integrated in spout (outlet);
ii)   integrated in the mixing body;
iii)   non-integrated (part of a set) above the maximum water level.
This document is not applicable to the product type non-integrated below the maximum water level.

This document specifies the:
field of application;
the dimensional, the physico-chemical, the design, the hydraulic, the mechanical and the acoustic characteristics of non-controllable backflow preventer with different pressure zones - family C - type A and of nominal sizes DN 6 to DN 50 inclusive and in nominal pressure PN 10.
It is applicable to:
-   Family C, type A, class "a" for general use: devices of class "a" shall be capable of working:
at any pressure up to 1 MPa (10 bar);
with any pressure variation up to 1 MPa (10 bar);
at a supply temperature limit of 65 °C and 90 °C for 1 h;
-   Family C, type A, class "b" for specific use: devices of class "b" shall be capable of working:
at any downstream pressure up to 300 kPa (3 bar);
with any downstream pressure variation up to 300 kPa (3 bar);
The devices of class "b" having specific hydraulic and no acoustic requirements and are meant for equipped filling devices built-in one or two functions boilers (heating only or heating and production of sanitation hot water).It concerns boilers with a 70 kW  maximum power and maximum temperature of 110°C.
It specifies also
-   test methods and requirements for verifying these characteristics;
-   marking;
-   presentation and the delivery.

This document specifies:
a)   field of application;
b)   requirements for pipe interrupters with atmospheric vent and moving element;
c)   dimensional and the physico-chemical properties, and the properties of general hydraulic, mechanical and acoustic design of pipe interrupters with elastic membrane of DN 10 to  DN 20;
d)   test procedure and requirements for verifying these properties;
e)   marking and presentation;
f)   acoustics.
This document specifies the characteristics of pipe interrupters with atmospheric vent and moving element, DN 10 to DN 20 that are suitable for use in drinking water systems at pressures up to 1 MPa (10 bar) and temperatures up to 65 °C and for 1 h at 90 °C.

This document specifies:
a)   field of application;
b)   requirements for pipe interrupters with permanent atmospheric vent;
c)   dimensional, the physico-chemical properties and the properties of general hydraulic, mechanical and acoustic design of pipe interrupters with permanent atmospheric vent, DN 10 to DN 20;
d)   test method and requirements for verifying these properties;
e)   marking and presentation;
f)   acoustics.
This document specifies the characteristics of pipe interrupters with permanent atmospheric vent, DN 10 to DN 20 that are suitable for use in drinking water systems at pressures up to 1 MPa (10 bar) and temperatures up to 65 °C and for 1 h 90 °C.
Backflow protection devices integrated in flushing valves are similar to DC and are not covered under this document. The requirements are stated in EN 12541.
This document specifies:
a)   field of application;
b)   requirements for pipe interrupters with permanent atmospheric vent;
c)   dimensional, the physico-chemical properties and the properties of general hydraulic, mechanical and acoustic design of pipe interrupters with permanent atmospheric vent, DN 10 to DN 20;
d)   test method and requirements for verifying these properties;
e)   marking and presentation;
f)   acoustics.
This document specifies the characteristics of pipe interrupters with permanent atmospheric vent, DN 10 to DN 20 that are suitable for use in drinking water systems at pressures up to 1 MPa (10 bar) and temperatures up to 65 °C and for 1 h 90 °C.
Backflow protection devices integrated in flushing valves are similar to DC and are not covered under this document. The requirements are stated in EN 12541.

This document specifies:
a)   field of application;
b)   requirements for hose union backflow preventer;
c)   dimensional and the physico-chemical properties and the properties of general hydraulic, mechanical and acoustic design of hose union backflow preventers DN 15  to DN 32;
d)   test method and requirements for verifying these properties;
e)   marking and presentation;
f)   acoustics.
This document specifies the characteristics of hose union backflow preventers DN 15 to DN 32 that are suit-able for use in drinking water systems at pressures up to 1 MPa (10 bar) and temperatures up to 65 °C and for 1 h at 90 °C.

The purpose of this European Standard is to specify:
-   field of application of Anti-pollution Check Valves;
-   backflow prevention properties, dimensional and physio-chemical properties, and properties of general hydraulic, mechanical and acoustic design to which Anti-pollution Check Valves of nominal sizes DN 6 to DN 250 inclusive shall conform;
-   Family E, type A, controllable Anti-pollution Check Valve (with test port);
-   Family E, type B, non-controllable Anti-pollution Check Valve, including Cartridge Check Valve;
-   Family E, type C, controllable Anti-pollution Double Check Valve (with test ports);
-   Family E, type D, non-controllable Anti-pollution Double Check Valve, including Cartridge Double Check Valve;
-   test procedures and requirements for verifying the backflow protection properties of stop valves, draw-off taps etc. which incorporate a check valve function. Stop valves, draw off taps etc, need also to comply with a recognised standard;
-   marking;
-   presentation at delivery.
This standard specifies the characteristics of Anti-pollution Check Valves of DN 6 up to and including DN 250 that are suitable for use in drinking water systems. For application feasibility see Table 1.
Table 1 - Nominal size vs Conditions of use
Nominalsize(DN)   Max. Operatingtemperature   Max. Operating pressure   Installation
DN <= 50                   65 °C + 90 °C, 1 hour   1 000 kPa (10 bar)                   Any position
DN > 50                   65 °C                                   1 000 kPa (10 bar)                   Horizontal only
Anti-pollution Check Valves covered by this standard are of Pressure Class PN 10.
The field of application of EN 1717 is limited to 10 bar, flanges could be drilled in PN 16 pattern.
Anti-pollution Check Valves of PN 16 shall satisfy the requirements of standard EN 13959 and comply with tests which characterise the PN of the device.

This European Standard specifies the characteristics and the requirements of air gaps with submerged feed incorporating air inlet and an overflow, Family A, type C. Air gaps are devices for protection of potable water in water installations from pollution. This standard applies to air gaps in factory assembled products and to constructed air gaps in situ and defines the physico-chemical characteristics of materials of construction used for the purpose and application to ensure compliance with this standard during normal working use.
Annex A specifies the vacuum test.

This European Standard specifies the characteristics and the requirements of air gaps with injector Family A Type D intended for protection of potable water in water installations from pollution.
This standard applies to air gaps in factory assembled products and to constructed air gaps in situ, and defines the physico-chemical characteristics of materials of construction used for the purpose and application to ensure compliance with this standard during normal working use.

This European standard applies primarily to copper alloy ball valves, dimensions DN 8 to DN 100, for potable water supply in buildings up to PN 10 and a distribution temperature of 65 °C. Occasional excursions up to 90 °C are permitted for a period of 1 h maximum.
This standard applies also to ball valves in combination with other components in the same body.
This standard specifies:
- the requirements of the materials and the design of ball valves;
- the mechanical, hydraulic and acoustic requirements of ball valves;
- the test methods to verify the requirements of ball valves;
- the marking requirements of ball valves.
Ball valves in combination with other valves should fulfil the same requirements.

This CEN standard specifies the characteristics of type AA air gaps for inlet or feed pipes. Air gaps that comply with the requirements of this standard are devices for protection of drinking water installations from pollution. In addition to factory assembled products this standard includes requirements for site constructed air gaps. This is a performance standard for "AA" air gaps. Materials of construction must be fit for the purpose and application to ensure compliance with this standard during normal working use.

This standard deals with the means to be used to prevent the pollution of potable water inside premises and the general requirements of protection devices to avoid pollution by backflow. The hygiene protection specifications ofthis standard are applicable to all the standards for systems or appliances connected to the private supply system for water intended for human consumption.This standard specifies the minimum requirements for product standards of protection units. The product standards are used to detail product specifications.

This European Standard specifies, dimensions, materials and performance requirements (including methods of test) for pressure safety valves, of nominal sizes from DN 15 to DN 40, having working pressures from 0,1 MPa (1 bar) to 1,0 MPa (10 bar). Pressure safety valves are intended for fitting to the cold water supply of storage water heaters, having a maximum distribution temperature of 95°C, for all energy sources. Pressure safety valves do not control the temperature and alone do not constitute the protection required for storage waters heaters.

This European Standard specifies, dimensions, materials and performance requirements (including methods of test) for combined temperature and pressure relief valves, of nominal sizes from DN 15 to DN 40, having working pressures from 0,1 MPa (1 bar) to 1,0 MPa (10 bar). Combined temperature an pressure relief valves are intended for fitting to storage water heaters, having a maximum distribution temperature of 95°C, for all energy sources.

The purpose of this Standard EN 1213 is to specify: - the requirements for the materials and the design of stopvalves; - the mechanical, hydraulic and acousticrequirements ; - the test methods; - the marking requirements; for copper alloy stopvalves for use with drinking water supply in buildings. This standard applies primarily to copper alloy stopvalves, dimensions DN 10 to DN 100, for potable water supply in buildings up to PN 10 and a distribution temperature of 65°C. Occasional excursions up to 95°C are permitted for a period of 1 hr. maximum.

This European Standard specifies dimensions, materials and performance requirements (including methods of test) for Water Pressrue Reducing Valves and Combination Pressure Reducing Valves, of nominal size from DN 8 to DN 100, for inlet pressures that do not exceed 1,6 MPa (16 bar) and a temperature that does not exceed 30°C for cold water application and 80°C for hot water application. Except when stated otherwise by the manufacturer, the valves can be mounted in any orientation.

This document specifies the characteristics and the requirements of air gap with injector Family A, Type D for nominal flow velocity not exceeding 3 m/s. Air gaps are devices for protection of potable water in water installations from pollution by backflow. This document applies to air gaps in factory-assembled products and to constructed air gaps in situ and defines requirements and methods to verify and ensure compliance with this document during normal working use.
The fluid in the receiving vessel is assumed to have similar properties to the water supply. Where this is not the case, additional care or tests may be required to verify the efficacy of the solution in practical use.
The AD device is intended to be used in potable water installations according to EN 806 (all parts).

This document applies primarily to copper alloy and stainless steel ball valves with dimensions DN 6 to DN 100, for installations in buildings for potable water supply up to PN16 and a maximum distribution temperature of 65 °C. Occasional excursions up to 90 °C are permitted for a period of 1 h maximum.
The ball valves are classified by their nominal pressure being either PN10 or PN16.
This document specifies:
-   the requirements of the materials and the design of ball valves;
-   the mechanical, hydraulic and acoustic requirements of ball valves;
-   the test methods to verify the requirements of ball valves;
-   the marking requirements of ball valves.

This document specifies an analysing methodology for protecting potable water in potable water installations within and outside buildings but within premises from the risk of pollution by backflow of non-potable water and gives recommendations on the design, risk analysis, backflow prevention devices and their installation methods (see Figure 1 and Figure 2).
This methodology is also intended to be used outside premises for all water systems connected to a potable water distribution system up to and including the point of use (see Figure 3).
The product standards for the specific backflow prevention devices or arrangements are intended to be used in conjunction with this document. For the development of new devices or systems, this document is intended to be used as a reference to establish the necessary level of backflow protection.

This European Standard specifies the characteristics and the requirements of air gap with non-circular overflow (unrestricted) Family A, Type B for nominal flow velocity not exceeding 3 m/s. Air gaps are devices for protection of potable water in water installations from pollution by backflow. This European Standard applies to air gaps in factory-assembled products and to constructed air gaps in situ, and defines requirements and methods to verify and ensure compliance with this European Standard during normal working use.

The purpose of this standard is to define - the field of application; - the dimensional, physico-chemical, design, hydraulic, mechanical and acoustic characteristics; - the working and the prescriptions for the tests to check , these characteristics; - the marking and the presentation. To be adhered to for reduced pressure principle backflow preventers, controllable BA.

This European Standard specifies, dimensions, materials and performance requirements (including methods of test) for expansion valves, of nominal sizes from DN 15 to DN 40, having working pressures from 0,1 MPa (1 bar) to 1,0 MPa (10 bar).  Expansion valves are intended for fitting to the cold 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 does not constitute the protection required for storage water heaters.

This European Standard specifies, dimensions, materials and performance requirements (including methods of test) for expansion groups, of nominal sizes from DN 15 to DN 40, having working pressures from 0,1 MPa (1 bar) to 1,0 MPa (10 bar). Expansion groups are intended for fitting to the cold water supply of storage water heaters, having a maximum distribution temperature of 95°C, for all energy sources. Expansion groups limit pressure, in the water heater to which they are fitted, that is produced by thermal expansion of the water.

This European Standard specifies:
a)   the field of application;
b)   the requirements of hose union anti vacuum valves;
c)   dimensional and physio-chemical properties, and properties of general hydraulic, mechanical and acous-tic design of hose union anti-vacuum valves of nominal sizes DN 15 up to and including DN 25;
d)   marking and technical product information.
This standard specifies the characteristics of hose union anti-vacuum valves of nominal size DN 15 up to and including DN 25 that are suitable for use in drinking water systems at pressures up to and including 1 MPa (10 bar) and temperatures up to and including 65 °C and for 1 h at 90 °C.
HB protects against back siphonage only and should be installed in vertical downward flowposition.
HB and HD anti-vacuum valves are for installation exclusively at the connecting point between stop valve and hose in vertical downward flow position.

This document specifies:
a)   field of application;
b)   requirements for in line anti-vacuum valves;
c)   dimensional, the physico-chemical properties and the properties of general hydraulic, mechanical and acoustic design of in-line anti-vacuum valves DN 8 to DN 80;
d)   test method and requirements for verifying these properties;
e)   marking and presentation;
f)   acoustics.
This document specifies the characteristics of in-line anti-vacuum valves DN 8 to DN 80 that are suitable for use in drinking water systems at pressures up to 1 MPa (10 bar) and temperatures up to 65 °C and for 1 h at 90 °C.

This European Standard specifies the characteristics and the requirements of air gap with non-circular overflow (unrestricted) Family A, Type B for nominal flow velocity not exceeding 3 m/s. Air gaps are devices for protection of potable water in water installations from pollution. This European Standard applies to air gaps in factory-assembled products and to constructed air gaps in situ, and defines the physico-chemical characteristics of materials of construction used for the purpose and application to ensure compliance with this European Standard during normal working use.

This European Standard specifies, dimensions, materials and performance requirements (including methods of test) for hydraulic safety groups, of nominal sizes from DN 15 to DN 40, having working pressures from 0,1 MPa (1 bar) to 0,7 MPa ( 7 bar). Hydraulic safety groups are intended for fitting to the cold water supply of storage water heaters, having a maximum distribution temperature of 95°C,, for all energy sources.

This European Standard specifies, the dimensional, the physico-chemical, the design, the hydraulic, the mechanical and the acoustic characteristics of mechanical disconnector, hydraulic actuated Family G, type B.
This European Standard is applicable to mechanical disconnectors hydraulic actuated in nominal sizes DN 8 up to DN 250 included, intended to prevent the return of water having lost its original sanitary and drinking qualities (called "polluted water" in this European Standard), into the potable water distribution system when-ever the pressure of the latter is temporarily lower than in the polluted circuit.
This European Standard covers the mechanical disconnectors hydraulic actuated of PN 10 that are capable of working without modification or adjustment:
-   at any pressure up to 1 MPa (10 bar);
-   with any pressure variation up to 1 MPa (10 bar);
-   in permanent duty at a limit temperature of 65 °C and 90 °C for 1 h maximum.
It specifies also the test methods and requirements for verifying these characteristics, the marking and the presentation at delivery.

This European Standard specifies, the dimensional, the physico-chemical, the design, the hydraulic, the mechanical and the acoustic characteristics of mechanical disconnector, direct actuated Family G, type A.
This European Standard is applicable to mechanical disconnector direct actuated in nominal sizes DN 8 up to DN 250 included, intended to prevent the return of water having lost its original sanitary and drinking qualities (called "polluted water" in this European Standard), into the potable water distribution system whenever the pressure of the latter is temporarily lower than in the polluted circuit.
This European Standard covers the mechanical disconnector direct actuated of PN 10 that are capable of working without modification or adjustment:
-   at any pressure up to 1 MPa (10 bar);
-   with any pressure variation up to 1 MPa (10 bar);
-   in permanent duty at a limit temperature of 65 °C and 90 °C for 1 h maximum.
It specifies also the test methods and requirements for verifying these characteristics, the marking and the presentation at delivery.

This European Standard specifies the characteristics and the requirements of air gap with non-circular overflow (unrestricted) Family A Type B for nominal flow velocity not exceeding 3 m/s. Air gaps are devices for protection of potable water in water installations from pollution. This standard applies to air gaps in factory assembled products and to constructed air gaps in situ, and defines the physico-chemical characteristics of materials of construction used for the purpose and application to ensure compliance with this standard during normal working use.
The annex A gives a relationship for rectangular overflow and the annex B is a note for alternative constructions.