1、BRITISH STANDARD Vacuum sewerage systems outside buildings The European Standard EN 1091 : 1996 has the status of a British Standard ICs 13.060.30 BS EN 1091 : 1997 U- NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW STD-BSI BS EN L72-ENGL 2797 LbZqbbS Ob30427 71T = Amd. No. BS
2、 EN 1091 : 1997 Date Text affected This British Standard, having been prepared under the direction of the Sector Board for Buiiding and Civil Engineering, was published under the authority of the Standards Board and comes into effect on 15 August 1997 O BSI 1997 Committees responsible for this Briti
3、sh Standard The preparation of this British Standard was entrusted by Technical Committee B/505, Wastewater engineering, to Subcommittee B/505/23, Vacuum and other special sewerage systems, upon which the following bodies were represented British Plastics Federation Chartered institution of Water an
4、d Environmental Management Depament of Environment (l3uilding Research Establishment) institute of Plumbing Water Services Association of England and Wales The following BSI references relate to the work on this Committee reference BI505123 Draft for comment 9W105013 DC ISBN O 680 27964 6 standard B
5、S EN 1091 : 1997 * m * O BSI 1997 Contents Committees responsible Nationai foreword Page inside front cover ii Foreword Text of EN 1091 2 3 i BS EN 1091 : 1997 National foreword This British Standard has been prepared by Technical Committee B/505, and is the English language version of EN 1091 : 199
6、6, Vacuum sewerage systems outside buildings published by the European Commitke for Standardization (CEN). The United Kingdom was an active participant in the draftuig process and voted for the finalclrail This standard does not supersede any British Standard. Cross-reference Publication referred to
7、 EN 752-2 Corresponding British Standard BS EN 752 Drain and sewer systems outside buildings Past 2 : 1997 Pe?$omuznce requirements Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages “his document comprises a front cover, an inside front co
8、ver, pages i and ii, the EN title page, pages 2 to 28, an inside back cover and a back cover. O BSI 1997 STD-BSI BS EN LOSI-ENGL 1977 m LbZYbbS 0b30?422 YOY m EUROPW STANDARD NORME EUR0PEE?E EuRopATscHE NORM EN 1091 December 1996 ICs 13.060.30 Descriptors: Sanitation, water removal, sewage water pip
9、elines, buildings, exterior, vacuum technology, performance evaluation, tests, design English version Vacuum sewerage systems outside buildings Rseaux d?assainissement sous vide l?extrieur des btiments Gebuden Unterdnickentwihse-e aui3erhalb von This European Standard was approved by CEN on 19961130
10、. CEN members are bound to comply with the CENICENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a nationai standard without any alteration. Upwe lists and bibliographical references concerning such national standards may be obtained on appli
11、cation to the Centrai Secretariat or to any CEN member. This European Standard 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 Central Secretariat has t
12、he same status as the officiai versions. CEN members are the national standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Irehd, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. European Committee for Standardizati
13、on Comit Europen de Nomakation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1060 Brussels O 1996 AU rights of reproduction and communication in any form and by any means reserved in ali countries to CEN and its members. Ref. No. EN 1091 : 1996 E STD*BSI BS EN LOSL-ENGL 1
14、797 = 1b29bb7 0b30Y23 390 Page 2 EN 1091 : 1996 Foreword Contents This European Standard has been prepared by Technical Committee CEN/rC 165, Waste Water Engineering, the Secretariat of which is held by DIN. “his European Standard shaii be given the status of a Foreword Introduction nationai b) floo
15、ding shall not occur or sha31 be limited to identifiable circumstances and prescribed frequencies; c) surcharging of collection chambers and sewers shall be imited to identifiable circumstances and prescribed frequencies; d) the system shall not endanger existing adjacent sbnidures and services; e)
16、the system shall be water and air tight as tested; f) odour, or other nuisance, shall not be gene-, g) provision shall be made for maintenance. 6.2 Performance and quantitative requirements 6.2.1 Gravitg drains New gravity drains discharging to collection chamber sumps shal be in accordance with EN
17、752-2. Where air inlet valves are installed on new gravity drains they shall be designed to suit the vacuum sewerage system 6.2.2 Flows fiwm interceptor sewers and commercial developments Where vacuum pipelines are used to intercept sewerage systems or accept domestic sewage from commercial developm
18、ents the design performance criteria including the peak flow shall be specified 6.2.3 Collection chamers NOTE. One or more properties may be connected to a collection chamber in accordance with local or national regulations. The chamber shall resist external forces and internal water pressure. The c
19、hamber shall be watertight. Frames andor covers shall prevent the ingress of surface water. Sepasate chambers shall be provided to serve properties at Merent elevations where there is a risk of sewage from one property flooding another property. Thermal conductivity calculations or recorded past per
20、formance shall demonstrate that the valve mechanism will function during the anticipated extremes of temperature. 6.2.4 Collection sumps Collection sumps shail be watertight Collection sumps serving domestic properties shall provide capacity to store a minimum of 25 % of average daily flow in the ev
21、ent of a power faiure or similar emergency; account may be taken of the storage in the gravity system. The sump sha be constructed of material which is corrosion resistant and unaffected by contact with sewage. The internal surface of the sump shall be smooth and the sump shall have benching to main
22、tain self cleansing flows. Where the interface valve is situated over the collection sump a working platform shail be provided if needed for health or safety reasons. The sump shall be sufficiently vented to allow the intake of air without causing a noise nuisance and to ensure that the operation of
23、 the vacuum system does not unseal the water traps on the gravity drainage system. NOTE. National or local regulations may require additional measures to prevent bacliooding from sumps inta houses. These measwes may include the provision of an ovedow from the sump to define a backnood level below wh
24、ich no sanitary apparatus may be fitted. O BSI 1997 STD-BSI BS EN LOSL-ENGL 1997 = 1b24bbS Db3042b 05T 6.2.6 InteMace valve The interface vaive shall fail safe in the closed position and shall prevent backflows from the semice connection to the collection sump. The sewer vacuum sha ensure positive v
25、alve seating. When the valve is open the flow path shall not be obstructed by the vaive mechanism. The vaive shail evacuate at least the batch volume each time it cycles. Vahres installed in the sump shall be capable of operating when submerged provided that the breather pipe is not also submerged T
26、he fixing arrangements shaii enable the interface valve andor control system to be readily replaced in not more than 30 min. 6.2.6 Level sensor The vahe shaU be equipped with a sensor to determine the level of sewage in the coiection sump; this sensor shall be designed to be fouling resistant. Level
27、 sensor pipes shall not be less than DND 45. 6.2.7 InteMace valve controller The controller shai open the valve only if there is a minimum partiai vacuum of 15 kPa below atmospheric available and shall maintain the valve fully open und at least the batch volume has been evacuated If the design provi
28、des for the introduction of air ailer the sewage has been evacuated the controller shaii maintain the valve open for a further period The controller shall be 4ustable so that a range of air to sewage ratios can be obtained. Controllers instaied in sumps shall be capable of operating when submerged.
29、6.2.8 Explosion proof The valve mechanism and controller shall be explosion proof if exposed to potentialy explosive atmosphere. Until a European Standard is produced the standards in the country of instailation shall be met. NOTE. National and local reguiations can prescribe explosive proof electri
30、cal equipment. 6.2.9 Life of membranes and seals The manufacturer shall on request state the operating life of valve membranes and other seals employed. 6.2.10 Vacuum pipeline components The vacuum pipeline components, including pipes, fittings, joints and sealing materials shall comply with prEN 12
31、93. 6.2.11 Pipe size The suction pipe DNAD shail not be greater than the DN/ID of the interface valve. The minimum diameter of service connections shall be DNAD 50 and shall be greater than the DNAD of the suction pipe. Vuum sewers shall have a minimum diameter of DN/ID 65 where nationai or local re
32、gulations control the discharge of gross solids to sewers. Vacuum sewers shall have a minimum diameter of DN/ID 80 where there are no such controls over the discharge of gross solids to sewers or where national or local regulations require larger diameters. NOTE. The maximum lengths of service conne
33、ctions and vacuum sewers corresponding to a particular DNAD may be specified. NOTE. Sharp bends should be avoided. O BSI 1997 Page 5 EN 1091 : 1996 6.2.12 Service connections Service connections shail initdy faii away from the interface valve and shall connect into the top sector of the vacuum sewer
34、 contained within the angle of It 60“ about the vertical axis. I Figure 1. Service connection 6.2.13 Branch connections Ail branch connections to vacuum sewers shall be by a junction connected to the sewer above the horizontal axis. In plan, the angle of the junction shall ensure that flow towards t
35、he vacuum Station is generated and bacliows are minimised. No connection shai be made within 2 m of a lift. 6.2.14 Isolation measures Means of isolating lengths of vacuum sewer to permit repairs or to locate fauts shall be provided at distances of not more than 450 m and on branch sewers longer than
36、 200 m. Buried valves shall have extension spindles and surface boxes. The valve clear opening shall be not less than the DNAD of the pipe. NOTE. Isolation valves or other means of isolation such as inspection pipes which allow the introduction of inflatable balls may be employed. Isolation valves s
37、hould be suitable for service in sewage under both vacuum and pressure should be capable of sustaining a differential vacuum of 80 kPa below atmospheric. 6.2.16 Vacuum vesseVsewage sump Each vessel shall be furnished with the required number of correctly sized sewage inlet and outlet pipes which sha
38、ll be integral with the vessel. No inlet pipes shall be connected below the system emergency stop leveL The inlet and outlet pipes shall be sited to encourage flow through the vessel and thus prevent the build up of solids. It shall be possible to inspect the vessel internally Each vessel shall be f
39、urnished with access openings to allow for internai inspection and cleaning. Each vessel shall be fitted with a level control system which is suitable for operation in a vacuum and is easily removed for a4psbnent or replacement. When the sewage sump is used in coNunction with ejector pumps it shaU h
40、ave a minimum liquid capacity of 400 1 per installed duty ejector. Page 6 EN 1091 : 1996 1 branch a) 1 I i / i 1, i I,/. i .I(-. i I - 1 3 /. a) direction of flow b) vertical angle Figure 2. Branch O BSI 1997 STD-BSI BS EN 1071-ENGL 1997 1b24bb9 Ob30Li28 922 6.2.16 Vacuum station control The controi
41、s shall pennit the selection of duty, duty assist (where provided) and standby vacuum generators and forwarding pumps and shail provide for the autodc introduction of the standby units in the event of failure. The vacuum generators sha be controlled by monitoring the vacuum in the vacuum vessel via
42、austable pressure switches set to the desired operating range. 6.2.17 Level control The level contsol system shall respond to the foliowing sewage levels in the vacuum vessel or the sewage sump: Emergency stop level - stops vacuum generation; Start level Normal stop level - forwarding pump(s) operat
43、e; - starts fowardlng pump(s); - stops forwarding pump(s); The following alarms with appropriate remote signahg shall be provided - low vacuum alarm, indicating that system vacuum is below the selected minimum preset level; - high sewage alarm, indicating that sewage level in the vacuum vessel or se
44、wage sump is at the high level mark - emergency alarm, indicating that a major piece of plant has failed or that the selected maximum continuous running time for the vacuum generator has been exceeded or that there is a power failure. Page 7 EN 1091 : 1996 5.2.21 Replacement sf forwaniing pumps Forw
45、arding pumps instailed outside the vacuum vessel shall be fitted with isolation valves to allow removal of the pump without disrupting the system operation. Where the discharge pipework is manifold the finai discharge pipe shall also be fitted with an isolation valve. Where forwarding pumps are inst
46、ailed inside the vacuum vessel it shall be possible to remove and replace a pump in not more than 4 h. Where system shutdown for 4 h is not acceptable pumps shaii be instaled externally unies two vacuum vessels are employed and the system can be operated with one vessel out of action. 6.2.22 Explosi
47、ve proof electrical equipment All electrical equipment operating in a potentiaiy explosive atmosphere shall be explosive proof. NOTE. National and local regulations can prescribe explosive proof electrical equipment. 6.2.23 Non-return valves Each discharge pipe from the vacuum vessel shall be fitted
48、 with non-return valves to prevent the black flow of sewage. Non-return valves shall also be fitted on the discharge pipework from each forwarding pump. Where the non-return valves, are instailed inside the vacuum vessel it shall be possible to remove and replace them in not more than 4 h. Where the
49、 discharge pipework is manifold the fmal discharge pipe shall also be fitted with a non-return valve. 6.2.24 aector pumps Where ejector pumps are employed as vacuum generators, unchokable sewage pumps of equal capacity shall be installed such that one pump can be capacity Isolation Valves shall be fitted to permit the 6.2.18 Equipment Vacuum generators (e.g. liquid ring or rotary vane to serve the system. A minimum of two vacuum Pumps Or ejer Pumps) have sufficient capacity removed for without loss of system gene*= of equal capacity One Pump be wed such remo
