1、STD-BSI BS EN Lb7L-ENGL 1997 D Lb24bb9 Ob57572 720 D 3s EN BRITISH STANDARD Pressure sewerage systems outside buildings The European Standard EN 1671 : 1997 has the status of a British Standard ICs 13.060.30 .671: 1997 n-m 1111 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW -
2、 - STD.BS1 BS EN Lb7L-ENGL 1977 m 1b24bb Ob59573 bb7 W BS EN 1671 : 1997 Amd. No. This British Standard, having been prepared under the direction of the Electrotechnicai Sector Board, was published under the authority of the Standards Board and comes into effect on 15 November 1997 Date Text affecte
3、d O BSI 1997 ISBN O 680 28623 I National foreword This Briish Standard is the English language version of EN 1671 : 1997. The UK participation in its preparation was entrusted by Technid Committee WW5, Waste water engineering, to Subcommittee B/505/23, Vacuum and other special drainage systems, whic
4、h has the responsibiiity to: - aid enquirem to understand the text; - present to the responsible European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; - monitor related international and European developments and promulgate them in the U
5、K A list of organizations represented on this subcommittee can be obtained on request to its secretary. Cross-references The British Standards which implement these intemational or European pubiications may be found in the BSI Standards Catalogue under the section entitled International Standards Co
6、rrespondence Index, or by using the Find facility of the BSI Standasds Electronic Catalogue. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, the EN tite page, pages 2 to 18, a
7、n inside back cover and a back cover. STD.BSI BS EN Lb7L-ENGL 1997 = 1b2LibbS b59594 5T3 m NORME EUROPENNE EUROPAscHE NOW EN 1671 June 1997 ICs 13.060.30 Descriptors: Sanitation, water removal, sewage, pressure pipes, specifications, design, components, dimensions, performance evaluation, installati
8、on, leak tests, maintenance, quality control English version Pressure sewerage systems outside buildIngs Rseaux dassainissement sous pression lextrieur des btiments Druckentw%semngqMeme annex A gives some useful information additional to this standard, annex I3 has the figures, annex C contains the
9、bibliography and national regulations, and annex D contains AdeWons. In drafting this European Standard account has been taken of other available draft Standards. According to the CENKENELEC Internal Regulations, the nai0na.l standards organimions of the following countries are bound to implement th
10、is European Standad Austria, Belgium, Czech Republic, Denmark, Finiand, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. contents Page Foreword 2 Introduction 3 1 1.1 1.2 1.3 1.4 2 3 3.1 3.2 3.3 4 4.1 4.2
11、4.3 4.4 4.6 Scope General Limit of design Application of pressure sewerage Sources of adclitiona information Nonnative references Defnitions collecting chamber pressure generating equipment Presure sewerage system (ES) System description General Main components Collecting chamber Pressure generating
12、 equipment Pipework systems CPSS) 3 3 3 3 3 3 4 4 4 4 4 4 4 4 5 5 5 5.1 6.2 6.3 6.4 6.5 6 6.1 6.2 6.3 6.4 7 8 9 10 10.1 10.2 10.3 Requirements General Essentia requirements Performance requirements Design requirements Calculation requirements Design and calculation of pressure sewerage systems Princ
13、iples Gas formation in sumps and pipes Systems calculation Pipe sizing Installation (pipelaying) Quality control Est methods Commissioning, operation and maintenance General Statutory considerations Cleaning of the pipes Annexes A A. 1 A.2 A.3 A.4 A.6 A.6 B C c.1 c.2 c.3 D (informative) Additional i
14、nformation Application of pressure sewerage systems System description Minimum velocities Design and calculation of pressure sewerage systems Installation (pipe-laYing Operation and maintenance (informative) Figures (informative) Bibliography and national regulations National regulations Bibliograph
15、y Additional bibliography (informative) AdeWons Page 5 5 5 6 6 6 6 6 6 7 7 7 7 8 8 8 8 8 9 9 9 10 10 11 11 12 16 16 16 16 17 O BSI 1997 STD.BSI BS EN Lb7L-ENGL 1997 Lb24bb9 Ob5959b 37b W * * B Introduction This European Standard covers positive pressure sewerage systems (PSS) and has been prepared f
16、or use by the designer, manufacturem, consultants, customers and operators. A PSS is designed to transport domestic wastewaker arising from dwellings and commercial properties and shall not be used for the disposai of stonnwater or rainwater. The PSS comprises a single pressure pipe or a branched ne
17、twork of pressure pipes. The pressure generating equipment is always located at the upstream end of the pressure pipe(s). The downstream boundary of the system is defned as the point at which the total flow from the system discharges from a single pipe at atmospheric pressure into a recipient e.g. m
18、anhole, gravity sewer or sump. The use of compressed air as the only means of generating pressure is not covered in this standard This stanhd covers the control of flow to the pumping main by random operation of pumps using i.e. level control and use of logic real-time control to manage pump output.
19、 However, the annex A is mainly concerned with random operations. The use of small bore pressure pipes in conjunction with PSS may result in reduced environmental impact and consequential reduction in site construction leading to lower instalation costs. 1 scope 1.1 General This European Standard sp
20、ecifies the performance, design, operation, maintenance and insWon with related verification and test method for positive pressure driven sewerage systems outside buildings carrying wastewater. It does not provide for the evaluation of conformity of systems to this European Standard. It does not spe
21、c - the pressure generating equipment (4.4); - compressed air unit, if required (4.4.2); - pipework (4.6); - pipejoints (4.6.2); - pump unit (4.4.1); - (4.6.3). figure B.l shows an example of a pressure sewerage system. 4.3 Collecting chamber The collecting chamber may serve one or more buildings. T
22、he maximum number of buildings Will be dictated by the capacity of the pressure generating equipment. Liability arising from the operation and maintenance of the collecting chamber, or local regulations, may dictate the use of separate collecting chambers for each dwelling or building. The essential
23、 elements of a collecting chamber are: - ventilation; - a suitably rated electrical supply; - controls and alarm equipment; - level control sensors within the chamber for automatic control of the pumps; - non-return valves and isolation valves to prevent back flow from the downstream system. Constsu
24、ction materials shall be suitable for operation with sewage. The working volume in the sump and the residual volume remaining at the end of the pumping sequence shall be designed to be as small as possible without adversely effecting the operation of the pump. (See also 4.2.) When designing and inst
25、aihg the chambers, due account should be taken of the risk of fracture of the pipework passing through the chamber wall, that may resuit from differential movement, vibrations etc. The bottom of the chamber shall be designed to be self cleansing to minimize the risk of sedimentation, and operate wit
26、h small working volume to minimize the retention time, an example of which is given in figures B.2 and B.4. All collecting chambers shall be designed to resist external forces. The collecting chamber shall be watertight and shall not leak. Access frames and covers shall prevent the ingress of surfac
27、e water. National or local regulations may allow use of collecting chambers inside buildings. Where indoor collecting tanks are used, an example of which is given in annex B, figure B.3, they shall incorporate a gas tight cover and be installed and insulated to prevent the transmission of noise and
28、vibration to the property Consideration shaii be given to the prevention of backfiow when designing a system incorporating collection tanks. The cover of a collecting sump is not necessarily gas tight Within the collecting sump the pump(s) are installed together with associated level control sensors
29、, pipework and valves. Figure B.2 illustrates an example of a typical collecting sump. See also A.2.1. O BSI 1997 STD-BSI BS EN Lb71-ENGL 1797 M lb2Libb9 b57598 149 m 4.4 Pressure generating equipment 4.4.1 Pump units Examples of pumps used in pressure sewerage systems are: - mutivane open impeller
30、pumps with grinding device; - semi-positive displacement pumps with grinding device; - single vane nonclogging centrifugai pumps; - vortex pumps. The most commonly used pumps in a PSS are submersible pumps, with or without grinding devices. The pumps are mounted inside the collecting sump (see colle
31、cting chamber, 4.3), with one or two pumps per sump. NOTE. F?ump(s) idare generally mounted externally to collecting tanks (see figure B.3). For the effective function of a F?SS ?standard execution motors? are normally used. However, national or local reguiations can demand explosion-proof certified
32、 motors and level control equipment. For further information see EN 60204-1. Air locks in the pumps shall be avoided See also A.2.2. 4.4.2 Air compressor units Compressed air may be used to support the flow of Wastewater. Where compressed air is required the compressed air station (static or mobile)
33、 should be located (or connected) upstream of the branch that needs support. The compressed air stations can be equipped with air compressors, compressed air reservoirs and compressed air release controls, or compressors which work directly on the pressure pipe without pressure reservoir. See also A
34、.2.3. 4.5 Pipework 4.6.1 General The pipes form a branched network or pipeline tract. The pipelines, in general, are laid to follow ground contour. High and low poins can be arranged as desired. Air bleeding devices (air release and/or air inlet valves or vent stack pipes), suitable for sewage appli
35、cations, might be necessary at high points. All high points shall be clearly identifed. Note though that odours and waterhammer might occur, which shall be checked in the planning stage. Page 5 EN 1671 : 1997 The whole pressure pipeline shall be constructed from corrosion resistant materiais unaffec
36、ted by permanent contact with wastewater, wastewater gases and surrounding ground conditions. The pipes shall have a smooth interior and be resistant to cyclic sresses. The pressure pipelines in a Collecting chamber and in the pipesystem shall be constructed to a minimum pressure rating of 600 kPa (
37、6 bar). Account should be taken of any long term loss of strength of the pipe material, e.g. where pipelines are instaled above ground or are likely to be subject to hot effluent. See ais0 prEN 476. Unused connections are to be sealed against the internai pressure and to prevent the ingress of groun
38、d water. Joins and their components shall comply with the relevant European Product Standard and be instailed in accordance with the manufacturer?s instructions. Until the European standard and unified regulations are available, standards and regulations at the place where the system is being constr
39、ucted shall apply. 4.5.2 Rpe-joints The pipe jointing system shall present a smooth unobstructed interior surface in order to avoid sedimentation and blockages. 4.6.3 Valves Isolation valves shall be provided to help facilitate maintenance, locate leakage and permit repairs, i.e. on each branch. 5 R
40、equirements 5.1 General The PSS shall transport the sewage from the collecting chamber(s) to the outlet under ali nod operating conditions. All PSS?s shall be designed to comply with national and local regulations. In addition, the PSS shall satisfy the following requirements. 6.2 Essential requirem
41、ents The essential requirements of a PSS are that: - there shail be no danger to public heath; - there shall be no danger to operating personnel; - the required design life and structural integrity shall be ensured. O BSI 1997 STD-BSI BS EN 1b71-ENGL 1997 W Lb24bb9 Ob59599 085 Page 6 EN 1671 : 1997
42、6.3 Performance requirements The performance requirements of a PSS are that: - the system shall operate without blockages; - flooding shall be eliminated or limited to identifiable circumstances and frequencies prescribed by national or local authorities; - surcharge of incoming gravity sewers shoul
43、d be eliminated or iimited to identifiable circumstances and frequencies; - they shall not endanger existing adjacent structures and services; - pipes shall be pressuretested in accordance with performance specifications; - odour or other nuisance shall not be generated - access for maintenance shal
44、l be ensured. In the event of power failure pressure generating equipment shall automatically restart on the re-estabiishing of the power supply. An acoustic and/or visual high level warning system shall be provided to indicate operational failure. The system shal fulfil the following design criteri
45、a, i.e. minimum velocity (see 6.4.2) and retention time of the wastewater in the pipes (see 6.4.3). 6.4 Design requirements 6.4.1 Pipes The pressure pipes shali have a bore equal to or exceeding the outlet bore of the pump. There shall be no decrease in the bore in the dbection of flow (see 4.4 and
46、7). Siphon effect in the pipe system that could result in clogging in the collecting chamber andor pump shall be considered. National or local reguhons may dictate the minimum bore of pipe that can be used in a PSS. This minimum bore may be influenced by the type of pressure generating equipment sel
47、ected 6.4.2 Minimum velocities In order to reduce the possibility of sedimentation and settling out of solids a minimum velocity of 0,7 m/s shail be achieved at least once in every 24 h. Velocities below 0,7 m/s may be acceptable during ce ci m is the internal diameter of pipe (bore); g d.$ is the a
48、cceleration due to gravilx 1 m is the length of the pipeline; v m/s is the velocity of water, - is the point loss factor (minor (pipe) loss factor) in the pipeline. When calculating the bt for different flows and presenting the result in a flow-head diagram the curve developed is usually called the
49、system curve. See also A.4.3.1. 6.3.2 Duty point in jlled pipes Pipelines shall be protected from freezing in accordance with local requirements. Benddjunctionshalves shall be stabilized appropriately Sharp changes in direction shall be avoided as far as is practicable in order to prevent blockages developing. Consideration should also be given to forces in the pipeline when empty and precautions taken against possible flotation. Where pipe joints occur they shall be appropriate for the type of pipe selected. See also A.5. The inte
