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1、BS EN 13077:2008 ICS 13.060.20; 23.060.99; 91.140.60 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BRITISH STANDARD Devices to prevent pollution by backflow of potable water Air gap with non-circular overflow (unrestricted) Family A Type B Licensed CopyChinese University of
2、Hong Kong, 20/10/2008 09:57, Uncontrolled Copy, (c) BSI This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 July 2008 BSI 2008 ISBN 978 0 580 56793 3 Amendments/corrigenda issued since publication DateComments BS EN 13077:2008 National forewor
3、d This British Standard is the UK implementation of EN 13077:2008. It supersedes BS EN 13077:2003 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee B/504/4, Backflow Prevention. A list of organizations represented on this committee can be obtained on re
4、quest to its secretary. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard cannot confer immunity from legal obligations. Licensed CopyChinese University of Hong Kong, 20/10/20
5、08 09:57, Uncontrolled Copy, (c) BSI BS EN 13077:2008 EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 13077 June 2008 ICS 13.060.20; 23.060.99; 91.140.60Supersedes EN 13077:2003 English Version Devices to prevent pollution by backflow of potable water - Air gap with non-circular overflow (unres
6、tricted) - Family A - Type B Dispositif de protection contre la pollution de leau potable par retour - Surverse avec trop-plein non-circulaire (to-tale) - Famille A - Type B Sicherungseinrichtungen zum Schutz des Trinkwassers gegen Verschmutzung durch Rckflieen - Freier Auslauf mit nicht kreisfrmige
7、m berlauf (uneingeschrnkt) - Familie A, Typ B This European Standard was approved by CEN on 29 May 2008. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration
8、. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translati
9、on under the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, G
10、reece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Manag
11、ement Centre: rue de Stassart, 36 B-1050 Brussels 2008 CENAll rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 13077:2008: E Licensed CopyChinese University of Hong Kong, 20/10/2008 09:57, Uncontrolled Copy, (c) BSI BS EN 13077:2008 EN 1307
12、7:2008 (E) 2 Contents Page Foreword3 Introduction.4 1 Scope 5 2 Normative references5 3 Terms and definitions .5 4 Designation 6 5 Symbolization.6 6 Materials .7 7 Requirements.7 8 Marking (not required for site constructed products) .12 9 Technical documents12 Annex A (informative) Relationship bet
13、ween h and l for air gap Family A, Type B with rectangular overflow13 Annex B (normative) Alternative overflow arrangements.14 B.1 General14 B.2 Horizontal overflow arrangement.14 B.3 Letterbox overflow extension arrangement15 Licensed CopyChinese University of Hong Kong, 20/10/2008 09:57, Uncontrol
14、led Copy, (c) BSI BS EN 13077:2008 EN 13077:2008 (E) 3 Foreword This document (EN 13077:2008) 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
15、of an identical text or by endorsement, at the latest by December 2008, and conflicting national standards shall be withdrawn at the latest by December 2008. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall
16、 not be held responsible for identifying any or all such patent rights. This document supersedes EN 13077:2003. Compared to the previous edition of the document the following changes have been made: a) definitions in Clause 3 revised; b) Annex B on alternative overflow arrangements added; c) editori
17、al errors corrected. 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, Cyprus, Czech Repub- lic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ic
18、eland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Licensed CopyChinese University of Hong Kong, 20/10/2008 09:57, Uncontrolled Copy, (c) BSI BS EN 13077:2008 EN 13077:200
19、8 (E) 4 Introduction In 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 restric- tion in any of the Me
20、mber State of the EU or EFTA; b) it should be noted that, while awaiting the adoption of verifiable European criteria, existing national regu- lations concerning the use and/or the characteristics of this product remain in force. Licensed CopyChinese University of Hong Kong, 20/10/2008 09:57, Uncont
21、rolled Copy, (c) BSI BS EN 13077:2008 EN 13077:2008 (E) 5 1 Scope 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 pota
22、ble 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
23、this European Standard during normal working use. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated refer- ences, only the edition cited applies. For undated references, the latest edition of the referenced document (including
24、 any amendments) applies. EN 1717:2000, Protection against pollution of potable water in water installations and general requirements of devices to prevent pollution by backflow 3 Terms and definitions For the purposes of this document, the terms and definitions given in EN 1717:2000 and the followi
25、ng apply. 3.1 air 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, and whose overflow is non-circular in design NOTE See Figure 1 for the design principle. Figure
26、1 Design principle 3.2 spillover level level at which water will start to overflow the receiving vessel with all outlets closed Licensed CopyChinese University of Hong Kong, 20/10/2008 09:57, Uncontrolled Copy, (c) BSI BS EN 13077:2008 EN 13077:2008 (E) 6 3.3 critical water level physical or piezome
27、tric level of the liquid reached in any part of the appliance 2 s after closing the water inlet starting from maximum level 3.4 dimension h height between the spillover level and the critical level NOTE See 7.4 for measurement and calculation. For example, see Annex A. 3.5 maximum level highest wate
28、r level H reached above the spillover level with flow rate Q applied and all outlets closed 3.6 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 or the DN of the inlet connection 4 Designa
29、tion An air gap with non-circular overflow (unrestricted) Family A, Type B is designated by: name; reference to this European Standard, i.e. EN 13077; family and type; denomination (see 3.7 DN or D). EXAMPLE Air gap, EN 13077, Family A, Type B, DN 15. 5 Symbolization The graphic representation of th
30、e air gap with non-circular overflow (unrestricted) Family A, Type B is as follows (see Figure 2). Figure 2 Graphic symbol Licensed CopyChinese University of Hong Kong, 20/10/2008 09:57, Uncontrolled Copy, (c) BSI BS EN 13077:2008 EN 13077:2008 (E) 7 6 Materials The manufacturer shall state the type
31、 of materials chosen in his technical and commercial documents. The materials used in water installations, including the materials of protection units in contact with drinking water, shall satisfy the European Standards and national acceptance criteria and/or national restrictions for use currently
32、in force in EU and EFTA. They 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 atmospheric outlet opening provided they do not have any
33、 harmful effect on the upstream part. 7 Requirements 7.1 General The protection assembly comprises three parts: water inlet device; receiving vessel (container); non-circular overflow. 7.2 Water inlet device Every float-operated valve or other device, which controls the inflow of water to a receivin
34、g vessel, shall be securely and rigidly fixed to that vessel. Every feed pipe supplying water to such a valve assembly or other device shall be fixed in its position to pre- vent it from moving or buckling. The feed pipe, inlet device and its outlet shall not come into contact in any way with a prod
35、uct from down- stream; it shall always be above level H (see Figure 3). When maintaining the maximum flow rate at normal operating conditions, if contact is observed between the upstream components and the liquid in the receiving vessel due to splashing, foaming or turbulence, the air gap shall be i
36、ncreased to a point where no contact is observed. Licensed CopyChinese University of Hong Kong, 20/10/2008 09:57, Uncontrolled Copy, (c) BSI BS EN 13077:2008 EN 13077:2008 (E) 8 Key A air gap (distance) D internal diameter of feed pipe (bore) H maximum level 1 feed pipe 2 feed orifice 3 receiving ve
37、ssel 4 spillover level 5 optional warning pipe 6 Uw 5h 7 critical water level (distance h) Figure 3 Air gap with non-circular overflow (unrestricted) Family A, Type B 7.3 Overflow arrangements The overflow arrangements shall be of non-circular design, shall discharge immediately into free air and sh
38、all be totally unobstructed. For air gaps Family A, Type B the critical water level shall be established and the air gap distance measured from the lowest point of the water inlet to the critical water level (see 3.3). The height of the overflow arrangement Ow is 2D + h and never less than 20 mm (se
39、e Figures 4 and 5). Licensed CopyChinese University of Hong Kong, 20/10/2008 09:57, Uncontrolled Copy, (c) BSI BS EN 13077:2008 EN 13077:2008 (E) 9 Key 1 Cw 5 h 2 Ow 2D + h and never less than 20 mm 3 l 10 h Figure 4 Rectangular overflow arrangement Key 1 Cw 5 h 2 Ow 2D + h and never less than 20 mm
40、 3 l 10 h Figure 5 Letterbox overflow arrangement For multiple inlets D is the largest feed pipe bore diameter. NOTE There is no relationship between the maximum water level and the top most level of the overflow arrangement. An additional circular warning pipe can also be fitted if required. Licens
41、ed CopyChinese University of Hong Kong, 20/10/2008 09:57, Uncontrolled Copy, (c) BSI BS EN 13077:2008 EN 13077:2008 (E) 10 7.4 Air gap distance 7.4.1 Single supply For 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
42、 the water inlet to the critical water level (see Figure 3). The distance A is 2D and not less than 20 mm and h is determined either by: a) measurement of the depth of water above the spillover level of the overflow arrangement, 2 s after the inflow equal to Q = 0,14D2 in litres per minute has stopp
43、ed or a dynamic pressure of 1 MPa (10 bar) has stopped if the flow rate Q cannot be achieved, where D is the bore of the inlet, (see 3.6) and with all out- lets including optional warning pipe (except the overflow arrangement) closed, based on velocity of 3 m/s, or the maximum recommended flow rate
44、for manufactured appliances, when the flow rate is higher than Q; b) calculating the depth of water above the spillover level of the overflow arrangement using the following equation: 3 2 3 143, 3 10 = l Q h (1) where Q is the inflow in litres per minute at 3 m/s (Q = 0,14 D2); l is the width of the
45、 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 t
46、han 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; see 7.4.1 a). 7.4.2 Multiple supplies In the case of multiple feed pipes
47、 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 (3.3) shall be determined 2 s after stopping the inflow with all feed pipes discharging at an indiv
48、idual in- flow calculated at Q = 0,14D2 in litres per minute. If the flow rate Q cannot be achieved, apply a dynamic pres- sure 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: = 2 2DA (2) Licensed
49、 CopyChinese University of Hong Kong, 20/10/2008 09:57, Uncontrolled Copy, (c) BSI BS EN 13077:2008 EN 13077:2008 (E) 11 7.4.3 Backflow/back pressure If the receiving vessel can be subject to positive pressure backflow, it is important that the inlet orifice is posi- tioned 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, it is essential that a means of limiting the flow rate to a rate
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