EN 13077-2018 Devices to prevent pollution by backflow of potable water - Air gap with non-circular overflow (unrestricted) - Family A - Type B.pdf

1、BSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06Devices to prevent pollution by backflow of potable water - Air gap with non-circular overflow (unrestricted) - Family A - Type BBS EN 13077:2018National forewordThis British Standard is the UK implementation of EN 1307

2、7:2018. It supersedes BS EN 13077:2008, which is withdrawn.The UK participation in its preparation was entrusted to Technical Committee B/504, Water supply.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include a

3、ll the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2018 Published by BSI Standards Limited 2018ISBN 978 0 580 95886 1ICS 13.060.20Compliance with a British Standard cannot confer immunity from legal obligations.This British

4、 Standard was published under the authority of the Standards Policy and Strategy Committee on 30 April 2018.Amendments/corrigenda issued since publicationDate Text affectedBRITISH STANDARDBS EN 13077:2018EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 13077March 2018ICS 13.060.20 Supersedes EN 130

5、77:2008EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGCEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2018 CEN Ref. No. EN 13077:2018: EAll rights of exploitation in any form and by any means reserved worldwide for CEN national Memb

6、ersDevices to prevent pollution by backflow of potable water - Air gap with non-circular overflow (unrestricted) - Family A - Type BDispositifs de protection contre la pollution de leau potable par retour - Surverse avec trop-plein non circulaire (totale) - Famille A, type BSicherungseinrichtungen z

7、um Schutz des Trinkwassers gegen Verschmutzung durch Rckflieen - Freier Auslauf mit nicht kreisfrmigem berlauf (uneingeschrnkt) - Familie A - Typ BThis European Standard was approved by CEN on 26 February 2018.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate

8、the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member.This European Standar

9、d exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions.CEN members are the nationa

10、l standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia

11、, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom.English VersionEN 13077:2018 (E)European foreword 3Introduction . 41 Scope . 52 Normative references 53 Terms and definitions . 54 Designation 65 Symbolization 66 Materials . 67 Requirements 77.1 General . 77.2 Water inlet d

12、evice . 77.3 Overflow arrangements 87.4 Air gap distance A 107.4.1 Single supply.107.4.2 Multiple supplies 107.4.3 Backflow/back pressure 117.5 Verification 117.5.1 General. 117.5.2 Procedure for verification by test (see 7.4.1 a) or 7.4.2)117.5.3 Procedures for verification by calculation 128 Marki

13、ng (not required for products constructed on-site) .129 Technical documents 12Annex A (informative) Relationship between h and l for air gap Family A, Type B with rectangular overflow .13Annex B (normative) Alternative overflow arrangements .14Annex C (normative) Vacuum Test .162Contents PageBS EN 1

14、3077:2018EN 13077:2018 (E)European forewordThis document (EN 13077:2018) has been prepared by Technical Committee CEN/TC 164 “Water supply”, the secretariat of which is held by AFNOR.This European Standard shall be given the status of a national standard, either by publication of an identical text o

15、r by endorsement, at the latest by September 2018, and conflicting national standards shall be withdrawn at the latest by September 2018.Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN not be held responsible for identifying a

16、ny or all such patent rights.This document supersedes EN 13077:2008.Compared to the previous edition of the document the following changes have been made:a) the scope has been adjusted;b) Figure 3 was updated and redrawn;c) terms and definitions were updated;d) mainly Clause 7 was revised and improv

17、ed;e) the entire standard was revised editorially.According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland,

18、Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.3BS EN 13077:2018EN 13077:2018

19、 (E)IntroductionIn respect of potential adverse effects on the quality of water intended for human consumption, caused by the product covered by this European Standard:a) this European Standard provides no information as to whether the product may be used without restriction in any of the Member Sta

20、te of the EU or EFTA;b) it should be noted that, while awaiting the adoption of verifiable European criteria, existing national regulations concerning the use and/or the characteristics of this product remain in force.4BS EN 13077:2018EN 13077:2018 (E)1 ScopeThis European Standard specifies the char

21、acteristics 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

22、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.2 Normative referencesThe following documents, in whole or in part, are normatively referenced in this document a

23、nd are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.EN 806-1, Specifications for installations inside buildings conveying water for human consumption P

24、art 1: GeneralEN 1717:2000, Protection against pollution of potable water in water installations and general requirements of devices to prevent pollution by backflow3 Terms and definitionsFor the purposes of this document, the terms and definitions given in EN 806-1 and EN 1717:2000 and the followin

25、g apply.3.1air gap with non-circular overflow (unrestricted) Family A, Type B (“AB” air gap)permanent and vertical distance between the lowest point of the inlet orifice and the critical water level of the receiving vessel having an overflow which is non-circular in designNOTE See Figure 1 for the d

26、esign principle. Figure 1 Design principle3.2spillover levellevel at which water will start to overflow the receiving vessel with all outlets closed3.3critical water levelphysical or piezometric level of the liquid reached in any part of the appliance 2 s after closing the water inlet starting from

27、maximum level5BS EN 13077:2018EN 13077:2018 (E)3.4dimension hheight between the spillover level and the critical levelNOTE See 7.4 for measurement and calculation. For example, see Annex A.3.5maximum levelhighest water level H reached above the spillover level with flow rate Q applied and all outlet

28、s closed3.6diameter 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 or DN of the inlet connection4 DesignationAn air gap with non-circular overflow (unrestricted) Family A, Type B is designated by:

29、 name; reference to this European Standard, i.e. EN 13077; family and type; denomination shall correspond to the type of connection of the inlet; maximum permitted flow rate.EXAMPLE Air gap, EN 13077, Family A, Type B, G 1/2, 14 l/min.5 SymbolizationThe graphic representation of the air gap with non

30、-circular overflow (unrestricted) Family A, Type B is as follows (see Figure 2).Figure 2 Graphic symbol6 MaterialsAll materials coming into contact with water intended for human consumption shall present no health risk nor cause any change of the drinking water in terms of quality, appearances, smel

31、l or taste. All materials shall be compatible among themselves and with the water supplied and with the fluids or substances that can come into contact with them.There are no special requirements concerning the materials downstream of the feed orifice provided they do not have any harmful effect on

32、the upstream part or the overflow arrangement.6 BS EN 13077:2018EN 13077:2018 (E)7 Requirements7.1 GeneralThe protection assembly comprises three parts: water inlet device; receiving vessel (container); non-circular overflow.7.2 Water inlet deviceEvery float-operated valve or other device, which con

33、trols the inflow of water to a receiving vessel, shall be securely and rigidly fixed to the vessel.Every feed pipe supplying water to such a valve assembly or other device shall be fixed in its position to prevent it from moving or buckling and to maintain a 2D radial clearance around the outlet. If

34、 a 2D clearance is not present in addition to the air gap validation a vacuum test in accordance with Annex C shall be undertaken.The direction of flow from a feed pipe into the receiving vessel shall be into air at atmospheric pressure, downwards and not more than 30 from the vertical. If the direc

35、tion of flow is not more than 15, the air gap shall be validated by calculation or by test, if it is more than 15 it shall be verified by test.The feed orifice shall not be in contact with the receiving vessel.No contact shall be observed between the upstream components and the liquid in the receivi

36、ng vessel.When maintaining the maximum flow rate at normal operating conditions, the feed pipe, inlet device and its outlet shall not come into contact in any way with a product from downstream; it shall always be above level H (see Figure 3).The water pathway to the overflow shall be unrestricted/u

37、nobstructed.7BS EN 13077:2018EN 13077:2018 (E)KeyA air gap (distance) 4 spillover levelD internal diameter of feed pipe (bore) 5 optional warning pipeH maximum level 6 Uw 5h(internal vertical surface)1 feed pipe 7 critical water level (distance h)2 feed orifice 8 2D Minimum radial clearance3 receivi

38、ng vessel a 15 maximum from the vertical(validation by test or calculation)b 30 maximum from the vertical(validation by test only)Figure 3 Air gap with non-circular overflow (unrestricted) Family A, Type B7.3 Overflow arrangementsThe overflow arrangements shall be of non-circular design, shall disch

39、arge immediately into free air and shall be totally unobstructed.Verification of the dimensions of the overflow arrangement shall be based upon the largest possible single rectangular that can be accommodated within the non-circular overflow.If the receiving vessel has more than one overflow arrange

40、ment, each one shall fulfil the given requirements. If the overflow has an extension (see Annex B) the air gap shall be verified by test as defined in 7.4.1 a).If the overflow is the only air inlet then a vacuum test shall be undertaken as defined in Annex C.8 BS EN 13077:2018EN 13077:2018 (E)The he

41、ight of the overflow arrangement Ow is 2D + h and never less than 20 mm (see Figures 4 and 5).Key1 Cw 5 h2 Ow 2D + h and never less than 20 mm (single inlet)Ow A + h and never less than 20 mm (multiple inlets)3 l 10 hFigure 4 Rectangular overflow arrangementKey1 Cw 5 h2 Ow 2D + h and never less than

42、 20 mm (single inlet)Ow A + h and never less than 20 mm (multiple inlets)3 l 10 hFigure 5 Letterbox overflow arrangementNOTE There is no relationship between the maximum water level and the top most level of the overflow arrangement. An additional warning pipe can also be fitted if required.9BS EN 1

43、3077:2018EN 13077:2018 (E)7.4 Air gap distance A7.4.1 Single supplyFor air gaps Family A, Type B the critical water level shall be established and the air gap distance A measured from the lowest point of the water inlet to the critical water level (h) (see Figure 3).The distance A is 2D and not less

44、 than 20 mm and h is determined either by:a) test by measurement of the depth of water above the spillover level of the overflow arrangement, 2 s after the inflow equal to Q = 0,14 D2in litres per minute has stopped. If the flow rate Q cannot be achieved then apply a flow pressure of 1 MPa (10 bar);

45、NOTE Where D is the bore of the inlet, (see 3.6) 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 byb) calculation by det

46、ermining the depth of water above the spillover level of the overflow arrangement using the following formula:whereQ is the inflow in litres per minute at 3 m/s (Q = 0,14 D2);l is the width of the overflow arrangement in millimetres.The calculation is only valid where: width (l) is greater than or e

47、qual to 10 h at the spillover level; crest thickness of the overflow arrangement (Cw) is less than or equal to 5 h; upstream internal vertical face of the overflow arrangement (Uw) is greater than or equal to 5 h; the depth of the overflow arrangement or notch (Ow) is greater than or equal to 2D + h

48、 and never less than 20 mm; the direction of flow from the feed pipe into the receiving vessel is downward and not more than 15 from the vertical; the overflow is rectangular in design.In all other cases the air gap dimension A has to be determined by test; see 7.4.1 a).7.4.2 Multiple suppliesIn the

49、 case of multiple feed pipes to a single vessel having a non-circular unrestricted overflow, the minimum air gap for the potable water supplies shall be dimension A above the critical water level using all (potable and non-potable) bore diameters D.For inlets having individual feed pipe bore diameters (D) of less than 25 mm then the critical water level (3.3) shall be determined by measurement only using 7.4.1 a).For inlets having one feed pipe bore diameters (D) greater or equal to 25 mm then the critical water level (3.3)