SIST EN 1825-2:2002

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Y]GUåHYDQMHAbscheideranlagen für Fette - Teil 2: Wahl der Nenngröße, Einbau, Betrieb und WartungInstallations de séparation de graisses - Partie 2: Choix des tailles nominales, installation, service et entretienGrease separators - Part 2: Selection of nominal size, installation, operation and maintenance13.060.30Odpadna vodaSewage waterICS:Ta slovenski standard je istoveten z:EN 1825-2:2002SIST EN 1825-2:2002en01-december-2002SIST EN 1825-2:2002SLOVENSKI
STANDARD



SIST EN 1825-2:2002



EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 1825-2February 2002ICS 13.060.30English versionGrease separators - Part 2: Selection of nominal size,installation, operation and maintenanceInstallations de séparation de graisses - Partie 2: Choix destailles nominales, installation, service et entretienAbscheideranlagen für Fette - Teil 2: Wahl der Nenngröße,Einbau, Betrieb und WartungThis European Standard was approved by CEN on 29 September 2001.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the 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 translationunder the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the officialversions.CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2002 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 1825-2:2002 ESIST EN 1825-2:2002



EN 1825-2:2002 (E)2ContentspageForeword.31Scope.32Normative references.33Terms and definitions.34Application.45Nominal size.56Selection of the nominal size.56.1General.56.2Determination of the specific values.56.2.1Maximum flow rate of wastewater.56.2.2Temperature factor ft.66.2.3Density factor fd.66.2.4Detergent and rinsing agent factor fr.76.3Special cases.76.4Determination of sludge trap volume.77Installation.87.1Limitations.87.2Place of installation.87.3Drainage to and from the separator.87.4Ventilation.88Operation, inspection and maintenance.9Annex A (normative)
Calculation of maximum wastewater flow Qs.10A.1Calculation based on equipment/fittings discharging into the separator.10A.1.1General.10A.1.2Maximum wastewater flow rate Qs.10A.2Method based upon the type of establishment discharging into the separator.11A.2.1General.11A.2.2Maximum wastewater flow rate Qs.11Annex B (informative)
Densities of greases and oils.14Annex C (informative)
Examples of determining nominal size of grease separator.16C.1Examples of calculation based on equipment/fittings discharging into the separator.16C.2Examples of calculation based on the type of establishment discharging into the separator.21Annex D (informative)
Measures to prevent grease accumulating and grease build-up in the pipelinesupstream of the grease separator.26Bibliography.27SIST EN 1825-2:2002



EN 1825-2:2002 (E)3ForewordThis document EN 1825-2:2002 has been prepared by Technical Committee CEN/TC 165 "Wastewaterengineering", the secretariat of which is held by DIN.This European Standard shall be given the status of a national standard, either by publication of an identical text orby endorsement, at the latest by August 2002, and conflicting national standards shall be withdrawn at the latest byJune 2004.When pollution control requires the treatment of pollutants other than light liquids, additional measures might benecessary.It is the second part of a two part standard for grease separators. Part 1 gives principles of design, performanceand testing, marking and quality control of grease separators.Annex A is normative. The annexes B, C and D are informative.According to the CEN/CENELEC Internal Regulations, the national standards organizations of the followingcountries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland,France, Germany, Greece, Iceland, Italy, Ireland, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain,Sweden, Switzerland and the United Kingdom.1 ScopeThis European Standard provides guidance on the selection of nominal sizes, installation, operation and mainten-ance of grease separators manufactured in accordance with prEN 1825-1.This standard does not apply to wastewater containing light liquids, e.g. grease or oils of mineral origin, and doesnot include treating stable emulsions of grease or oil in water.The standard does not cover the use of biological additives (bacteria, enzymes).2 Normative referencesThis European Standard incorporates by dated or undated references, provisions from other publications. Thesenormative references are cited at the appropriate places in the text, and the publications are listed hereafter. Fordated references, subsequent amendments to or revisions of any of these publications apply to this EuropeanStandard only when incorporated in it by amendment or revision. For undated references the latest edition of thepublication referred to applies (including amendments).prEN 1825-1:2000, Grease separators — Part 1: Principles of design, performance and testing, marking and qualitycontrol.EN 12056-2, Gravity drainage systems inside buildings — Part 2: Sanitary pipework, layout and calculation.3 Terms and definitionsFor the purposes of this European Standard the terms and definitions given in prEN 1825-1 and EN 12056-2 andthe following apply.SIST EN 1825-2:2002



EN 1825-2:2002 (E)43.1selection of the nominal sizedetermination of the appropriate nominal size of the grease separation chamber for a specific case, based onamount and type of influent4 ApplicationGrease separators shall be used wherever it is necessary to separate greases and oils of vegetable and animalorigin from wastewater, such as in trade or industrial plants/establishments, e.g. commercial kitchens and large catering establishments, e.g. in inns, hotels, motorways service stations,canteens; grilling, roasting and frying facilities; food distribution points (with returnable crockery); butcher's shops, with or without slaughtering facilities; meat and sausage factories, with or without slaughtering facilities; abattoirs; poultry slaughterers; tripe preparation plants; animal rendering plants; bone and glue boiling plants; soap and stearine factories; oil mills; vegetable oil refineries; margarine factories; pickling plants; fast-food preparation plants; chip and crisp producers; peanut roasting plants.Wastewater containing a considerable proportion of grease in a non-separable form (i.e. emulsified) fromapplications such as dairy, cheese making and fish processing, or from distribution points having only dish washingfacilities, or from "wet waste compactors", will only be effectively treated in grease separators under certainconditions. The wastewater may require further treatment.Applications where the discharged wastewater contains solids that are quick to purify (e.g. the fish industry) do notrequire a sludge trap, but the grease separator shall be fitted with a strainer or screening device fitted on the inletside to retain coarse solids. Any retained solids should be removed and the separator thoroughly flushed with cleanwater before operational intervals to prevent putrefaction.SIST EN 1825-2:2002



EN 1825-2:2002 (E)55 Nominal sizeFor the preferred nominal sizes (NS) see clause 4 of prEN 1825-1:2000.Multiple separators of the same nominal size may be connected in parallel with the flow split equally between eachseparator.6 Selection of the nominal size6.1 GeneralThe selection of the nominal sizes shall be based on the nature and quantity of wastewater to be treated taking intoaccount: maximum flow rate of wastewater; maximum temperature of the wastewater; density of grease/oils to be separated; influence of cleansing and rinsing agents.If a grease storage capacity greater than 40 · NS in litres is required, e.g. when more than the usual amount ofgrease is expected, the following options may be used:1) using a larger nominal size separator than calculated or2) creating grease storage capacity outside the separator or3) emptying the separator more frequently than usually.Where no specific sizing method is offered by a regulatory authority, then the nominal size of the separator shall bedetermined from the following formula:rdtsNSfffQ(1)whereNSis the calculated nominal size of the separator;Qsis the maximum flow rate of wastewater, entering the separator in litres per second;ftis the impedient factor for the temperature of influent;fdis the density factor for the relevant grease/oil;fris the impedient factor for the influence of cleansing and rinsing agents.After calculation select the next higher preferred nominal size in accordance with clause 4 of prEN 1825-1:2000.6.2 Determination of the specific values6.2.1 Maximum flow rate of wastewaterThe maximum flow rate of wastewater Qs shall be determined by:SIST EN 1825-2:2002



EN 1825-2:2002 (E)6a) measurement, orb) calculation based upon catering equipment discharging into the grease separator, orc) calculation
based upon the type of establishment discharging into the grease separator, ord) special calculation for individual cases, if acceptable by the regulatory authority.Where data is available to determine Qs by b) or c), and the designer is unsure of the most appropriate option ofuse, it is recommended that the higher of the flow rates determined from both calculations is used.6.2.2 Temperature factor ftHigh wastewater temperature reduces the efficiency of grease separators. Temperature factors ft are given inTable 1.Table 1 — Temperature factor ftTemperature of wastewater at inlet°CTemperature factor ft1,0always or occasionally > 601,36.2.3 Density factor fdA density factor fd = 1,0 shall be used for wastewater discharged from kitchens, abattoirs and meat and fishprocessing plants.When the nature of grease/oil is well known, the density coefficient may be taken from Figure 1, where fd is plottedfor a range of different grease and oil densities.For grease/oil densities > 0,94 g/cm3, a density factor of 1,5 shall be used.Densities of different fats and oils are given in annex B.SIST EN 1825-2:2002



EN 1825-2:2002 (E)7Figure 1 — Relation between fd and density6.2.4 Detergent and rinsing agent factor frDetergents, including dishwasher powders and rinsing agents, should carefully be selected and used sparingly.They shall not impair the separating effect as far as possible and not form stable emulsions where they are usedupstream of a separator. A detergent and rinsing agent coefficient shall be chosen from Table 2.Table 2 — Detergent and rinsing agent coefficient frUse of detergent and rinsing agentsDetergent and rinsing agent coefficient frNever used1,0Occasionally or always used1,3Special cases, e.g. hospitalsNational and local regulations may limit the use of certain detergents, rinsing agents and solvents.6.3 Special casesFor industrial plants such as abattoirs and wholesale butchers, the grease separator nominal size NS should beselected on the basis of site specific investigation.6.4 Determination of sludge trap volumeThe sludge trap volume shall be at least 100 · NS in litres but for abattoirs and similar plants a volume of at least200 · NS in litres is recommended.SIST EN 1825-2:2002



EN 1825-2:2002 (E)87 Installation7.1 LimitationsOnly wastewater containing organic grease and oils shall be discharged to a grease separator. In particular, thefollowing shall not be discharged to a grease separator: wastewater containing faeces ("black" water); rainwater; wastewater containing light liquids, e.g. grease or oil of mineral origin.7.2 Place of installationGrease separators should be installed close to the sources of wastewater but should not be sited in unventilatedrooms, roads, car parks or storage areas. To prevent odour and fly nuisance, separators should not be sited closeto habitable buildings, especially to opening windows and air intakes. They shall be easily accessible to cleaningvehicles. Specific operational and structural conditions may require the separator to be remotely located from thesource of wastewater.Separators should be installed in such a way to prevent frost damage, and allow all parts requiring regularmaintenance to be easily accessible at all times.Where necessary, manhole covers on separators shall be supported so that the load imposed on the separatordoes not exceed its design strength.7.3 Drainage to and from the separatorWhere no specific local regulations exist, grease separators shall be connected to the drains and sewers asfollows:The wastewater to the grease separator shall be gravity fed. If the static water level in the grease separator is lowerthan the flood level (see EN 752-1), then the effluent from the separator shall be discharged to the drainage systemusing a wastewater lifting plant.Pipelines upstream of the separator shall be laid at a minimum gradient of 2 % (1 : 50) to prevent an accumulationof grease. Where for structural and/or operational reasons, this is not possible, and/or longer pipe runs arerequired, appropriate measures shall be taken to prevent grease accumulation or deposition (see annex D).The transition from vertical to horizontal pipes shall be made by using two 45° bends between which a piece ofpipe, at least 250 mm long, shall be placed, or by using equivalent long-radius bend. This shall be followed by astilling section that has a length, in millimetres, equal to at least 10 times the nominal size of the supp
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