1、February 2011DEUTSCHE NORM DIN-Normenausschuss Wasserwesen (NAW)DIN-SprachendienstEnglish price group 10No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale f
2、or German Standards (DIN-Normen).ICS 13.060.20; 91.140.60!%jv“2027183www.din.deDDIN 1988-500Codes of practice for drinking water installations Part 500: Pressure boosting stations with RPM-regulated pumps; DVGW Code of practice,English translation of DIN 1988-500:2011-02Technische Regeln fr Trinkwas
3、ser-Installationen Teil 500: Druckerhhungsanlagen mit drehzahlgeregelten Pumpen; Technische Regel des DVGW,Englische bersetzung von DIN 1988-500:2011-02Directives techniques relatives aux installations deau potable Partie 500: Installations de relevage de compression par des pompes avec une vitesse
4、derotation rgle; Directive technique du DVGW,Traduction anglaise de DIN 1988-500:2011-02SupersedesDIN 1988-500:2010-10www.beuth.deDocument comprises 15 pages03.16 DIN 1988-500:2011-02 2 A comma is used as the decimal marker. Contents Page Foreword . 3 1 Scope . 4 2 Normative references . 4 3 Terms a
5、nd definitions 4 4 Design principles 6 4.1 General . 6 4.2 Supply pressure 6 4.3 Pressure increase . 6 4.4 Supply security and hygiene . 7 4.5 Flow rate 8 4.6 Pump differential pressure 8 4.7 Pressure zones . 8 4.8 Types of connection . 11 4.8.1 General . 11 4.8.2 Direct connection 11 4.8.3 Indirect
6、 connection . 11 4.9 System components . 11 4.9.1 Pressure measurement 11 4.9.2 Pressure reducing valve 11 4.9.3 Expansion vessels 11 4.9.4 Break tank 11 4.9.5 Pressure boosters 12 4.9.6 Valves . 13 4.9.7 Pressure-relief valve . 13 4.9.8 Set-up and pipe connections . 13 4.9.9 Pressure booster locati
7、on . 13 5 Operational readiness 14 6 Inspection and maintenance . 14 Bibliography . 15 DIN 1988-500:2011-02 3 This standard has been prepared in agreement with the DVGW Deutscher Verein des Gas- und Wasserfaches e.V. (German Association of Gas and Water Engineers). It has been included in its body o
8、f technical rules and codes of practice for water. Foreword This standard has been prepared by Working Committee NA 119-04-07 AA Husliche Wasserversorgung of the Normenausschuss Wasserwesen (Water Engineering Standards Committee). DIN EN 806-2:2005-06, Clause 15, describes design principles for wate
9、r pressure boosting systems with constant speed pumps. The use of such pumps can lead to pressure fluctuations and frequently requires the installation of diaphragm expansion tanks upstream and downstream, which can lead to health hazards or the impairment of drinking water quality. The design and i
10、nstallation requirements of the present standard, DIN 1988-500, make it possible to meet more stringent requirements for comfort, hygiene and energy efficiency to be satisfied. This modern booster design normally makes it possible to dispense with diaphragm tanks and ensures the maintenance of a con
11、stant pressure within the range of characteristic curves. This national standard is included in the set of technical rules on drinking water supply systems which apply in Germany, namely the Technische Regeln fr Trinkwasser-Installationen (TRWI) (Codes of practice for drinking water installations),
12、which comprises several European Standards and the corresponding supplemental national provisions. Amendments The following correction has been made to DIN 1988-500:2010-10: a) the restriction that the standard is not to be used for new designs has been deleted from the title. Previous editions DIN
13、1988-500: 2010-10 DIN 1988-500:2011-02 4 1 Scope This standard specifies criteria for the design and installation of water pressure boosting systems (“pressure boosters”, for short) as part of drinking water installations which will ensure fault-free and economic operation. This standard does not co
14、ver pressure boosters that are only used for the purposes of extinguishing fires (see DIN 14462). NOTE See DIN EN 806-1 for terms and definitions, graphical symbols, units and abbreviations. 2 Normative references The following referenced documents are indispensable for the application of this docum
15、ent. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. DIN 1986-100, Drainage systems on private ground Part 100: Specifications in relation to DIN EN 752 and DIN EN 12056 DIN 1988-3, Codes
16、of practice for drinking water installations Pipe sizing; DVGW Code of practice DIN 4109 (all parts), Sound insulation in buildings DIN 4807-5, Expansion vessels Part 5: Closed expansion vessels with membrane for drinking water installations Requirements, test, design and designation; DVGW Code of p
17、ractice DIN EN 806-2:2005-06, Specifications for installations inside buildings conveying water for human consumption Part 2: Design DIN EN 1717, Protection against pollution of potable water in water installations and general requirements for devices to prevent pollution by backflow; Technical rule
18、 of the DVGW DIN EN 12056 (all parts), Gravity drainage systems inside buildings AD 2000-Merkblatt A 2, Sicherheitseinrichtungen gegen Druckberschreitung Sicherheitsventile (Safety devices against excess pressure Safety valves)1)3 Terms and definitions For the purposes of this document, the followin
19、g terms and definitions apply. 3.1 lowest normal service pressure SPLN minimum flow pressure at the point of delivery occurring during periods of high demand according to information provided by the water supplier 3.2 maximum supply pressure maximum static pressure at the point of connection of the
20、service pipe to the public water main according to information provided by the responsible water supplier 1)Obtainable from Beuth Verlag GmbH, 10772 Berlin. DIN 1988-500:2011-02 5 3.3 flow pressure PFL gauge pressure at a measuring point of a drinking water installation under flow conditions 3.4 min
21、imum flow pressure PminFL static pressure required at the draw-off point of a water tap to achieve the minimum flow rate 3.5 pump differential pressure Pp difference between the pressure at the delivery pressure side of the pump of a pressure booster and the pressure immediately upstream of the boos
22、ter pumps at a given flow rate 3.6 head loss pressure loss P difference in pressure at two points of the drinking water installation due to pipe friction and other resistances 3.7 head loss due to difference in elevation Pe product of the difference in elevation, acceleration due to gravity and the
23、density of water 3.8 peak flow rate QD flow rate as a basic parameter in hydraulic design and allowing for the simultaneous demand of water likely to be expected in service 3.9 effective capacity VB effective volume of the break tank installed upstream of the booster pumps DIN 1988-500:2011-02 6 4 D
24、esign principles 4.1 General Installation of a pressure booster is only required where the lowest normal service pressure is less than the sum of the total head loss across the drinking water installation, the head loss due to difference in elevation, and the minimum flow pressure. This is to be che
25、cked by making a detailed calculation of head losses, whereby an economic operation of the system is to be considered when determining friction and individual resistances (i.e. 1 kPa/m to 2 kPa/m) (see Figure 1). Key 1 Lowest normal service pressure 2 Service pipe Figure 1 Drinking water installatio
26、n without a pressure booster 4.2 Supply pressure Pressure boosters shall be designed on the basis of the lowest normal service pressure SPLN (3.1) and the maximum supply pressure (e.g. as declared by the water supplier) and any other technical requirements (e.g. design flow rate). 4.3 Pressure incre
27、ase The increase in pressure shall be the difference between the flow pressure PFl(3.3) and the lowest normal service pressure SPLN (3.1) (see Figure 2). DIN 1988-500:2011-02 7 Key 1 Water main 2 Service pipe Figure 2 Pressure boosting 4.4 Supply security and hygiene Pressure boosters shall be desig
28、ned, operated and maintained so as to ensure continuous and safe operation of the drinking water installation and so that neither the public water supply nor other connected systems are adversely effected. Any adverse changes to the drinking water quality, especially in terms of hygiene, shall be pr
29、ecluded. DIN 1988-500:2011-02 8 4.5 Flow rate The necessary flow rate (peak flow rate QD) of pressure boosters shall be calculated as specified in DIN 1988-3. The maximum flow rate in the pipe serving the pressure booster shall not exceed the values, specified in DIN 1988-3. The maximum difference i
30、n the flow velocities in the service pipe and in the pipe serving the pressure booster, generated by operation of the level switches of each booster pump or of valves, shall be less than or equal to 0,15 m/s, and shall not exceed 0,5 m/s in the event of failure of all pumps (e.g. as a result of powe
31、r failure). This is to ensure that the static pressure in the service pipe and in the pipe serving the pressure booster does not rise by more than half and by less than 0,1 MPa when each pump or valve starts, and by no more than 0,1 MPa when they are switched off. NOTE 1 The limitation of flow veloc
32、ities is required in order to prevent unacceptable drops in the mains pressure in neighbouring systems, as well as pressure surges in service pipes and the distributing pipework of the central water supply system. NOTE 2 Pressure surges and fluctuations in flow velocity are normally not caused by th
33、e pressure booster but by downstream consumers, valves, appliances and cisterns. 4.6 Pump differential pressure The pump differential pressure Pp(3.5) is obtained as the sum of the head loss due to difference in elevation Pe(3.7), the minimum flow pressure PminFl (3.4) at the draw-off point with the
34、 most unfavourable location, and the head loss P(3.6) due to friction and individual resistances, minus the lowest normal service pressure SPLN (3.1) (cf. Figure 2). The available flow pressure downstream of the pressure booster is obtained as the sum of the lowest normal service pressure SPLN (3.1)
35、 and the pump differential pressure Ppof the pressure booster (3.5). 4.7 Pressure zones Where the system is designed to include a number of pressure zones, one of the following configurations can be used. For reasons of energy efficiency, the pressure zones should be selected so as to minimize the n
36、ecessity of using pressure reducing valves. DIN 1988-500:2011-02 9 Configuration A The water is supplied directly to the site via the public main; pressure boosters are installed only where required (see Figure 3). Key 1 Pressure zone 1 2 Pressure zone 2 Figure 3 Configuration A Configuration B Seve
37、ral pressure boosters are installed so that there is a separate pressure booster in each pressure zone (see Figure 4). Key 1 Pressure zone 1 2 Pressure zone 2 Figure 4 Configuration B DIN 1988-500:2011-02 10 Configuration C One pressure booster with a central pressure reducing valve for each pressur
38、e zone (see Figure 5). Key 1 Pressure zone 1 2 Pressure zone 2 Figure 5 Configuration C Configuration D One pressure booster with one pressure reducing valve per storey (decentral) (see Figure 6). Key 1 Pressure zone 1 2 Pressure zone 2 3 Pressure zone 3 4 Pressure zone 4 Figure 6 Configuration D DI
39、N 1988-500:2011-02 11 4.8 Types of connection 4.8.1 General Pressure boosters can be connected to the installation directly or indirectly. For reasons of drinking water hygiene and energy efficiency, a direct connection should be given preference. 4.8.2 Direct connection A direct connection is one i
40、n which the pressure booster is installed in the supply pipe so as to form a closed system. Since the supply pressure acts directly on the pressure booster, a lower input power to drive the booster will be required. 4.8.3 Indirect connection In indirectly connected boosting systems, an atmospheric b
41、reak tank (with a free outlet) is installed between the pumping unit and the service pipe. An indirect connection is required where, for example, the lowest normal service pressure SPLN is 100 kPa, the minimum flow pressure PminFlrequired at the maximum flow rate through the pressure booster, taking
42、 upstream draw-off points into consideration, is not achieved, or a temporary demand is to be satisfied. 4.9 System components 4.9.1 Pressure measurement For monitoring the service pressure, a pressure gauge (preferably fitted with a trailing pointer) shall be installed directly behind the water met
43、er. 4.9.2 Pressure reducing valve A pressure reducing valve only needs to be installed upstream of the pressure booster if the pump and the system characteristics so require. 4.9.3 Expansion vessels Downstream expansion vessels do not need a switching function. Low capacity vessels may be required t
44、o allow for short-time draw-off or changes in volume due to thermal effects. Expansion vessels shall conform to DIN 4807-5 and, for example, bear a DVGW certification mark. 4.9.4 Break tank 4.9.4.1 Effective capacity The effective capacity of the break tank is a function of the lowest normal service
45、 pressure SPLN (3.1) in the water main or the available pressure upstream of the break tank, and of the peak flow rate QDin the pipework downstream of the pressure booster. DIN 1988-500:2011-02 12 The effective capacity VBis to be calculated from the following equation: VB 0,03 QD(1) where VBis the
46、effective capacity, in m3; QDis the peak flow rate, in m3/h. Where the required peak flow rate QDcannot be generated from the supply pressure in the water main, the effective capacity of the tank shall be determined using the mass-curve method. 4.9.4.2 Design of break tank The design, materials used
47、 and water inlet control device of break tanks shall conform to DIN EN 806-2:2005-06, 19.1.3, 19.1.5 and 19.1.8. The protection unit shall be of type AB (air gap) as in DIN EN 1717. The level indicator shall be designed so as not to cause any inacceptable changes in flow velocity or pressure surges.
48、 Any deformation of the break tank due to the lifting force of the inlet valve (float) shall be precluded. The tank design shall ensure a laminar flow of the water at the inlet and that there is no suction of air by the downstream pressure booster. To ensure a uniform water exchange, there shall be no stagnation zones. An air break to drain for run-off water (as specified in DIN EN 1717) shall be realised even in the case of failure of the level indicator. 4.9.5 Pressure boosters Pressure boosters shal
