BRITISH STANDARD

Vitrified clay pipes andfittings and pipe jointsfor drains and sewerPaft7z Requirements for vitrified claypipes and joints for pipe jacking

The European Standard EN 295-?:1998 has the status of aBritish StaDdard

ICS 23.040.30; 23.040.50

NO COPYINC WITEOIJT BSI PEEMISSION TXCEPT AS PEBMIMED BY COPIBICET LAW

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BS EN295-7:L996

BS EN 295-7:1996

Committees responsible for thisBritish Standard

The preparation of this British Standard was entrusted by TechnicalCommittee 8/505, Waetewater engineering, to Subcomm.ittee Bl5O5l2' Claypipes, upon which the foltowi.og bodies were represented:

Department of the EnvironmentFederation of Civil EDgineering ContractorsInstitution of Civil EugineersInstitution of Water and Environmeotal MauagemeDtSociety of British Water IudustdesWater Services Association ofEngland and WalesCo-opted members

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Thi6 British Standard, havinsbeen prepared urider th directionof the Sector Boald for Brdldingand Civil Ensineering, waspublished under the authority ofthe Standards Board snd comesht efrect on16 April 1996

o BSI 09-1999

The folowiDg BSI ieferencesrelate to the wolk on thisstaDdard:Conrnittee reference 8/505/2Draft for comment 93/104:]62 DC

ISBN 0 680 25431 3

Amendments i ssued s ince pub l ica t ion

BS EN 295-7:1996

List of references

See uational foreword.

@ BSI 09 1999

BS EN295-7:1996

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BSI389 Cbiswick High RoadLondonW4 4AL

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EUROPEAN STANDARDNORME EUROPEENNEEUROPAISCHE NORM

EN 295-7

October 1995

ICS 23.040.30; 23.040.50

Descriptors: Saaitrtion, watr remova! watr pipelires, pipes: tubes, accessories, sandstone product, asmbling, thrust boring,specificationa, dimensions, designation, msrkirg

English version

Steinzeugrohre und Formstiicke someRohrverbildungen fiir Abwasserleitungen und-kaniile - Teil 7: Anforderungen anSteinzeugrohre und Verbi-ndungen beimRohrvortrieb

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This European Stardard was approved by CEN on 1995-0?-02. CEN Eembersare bouucl to comply with the CENiCENELEC IntBrnal Regulatious whichstipulate the conditions for giving this European Staudarcl the etatus of anational standaril without aay alteratiou.Up-to-date lists and bibliographical references concerning such nationalstandards may be obtabed on application to the Central Secretariat or to anyCEN member.This Europeau Staudard exists in three o6cial versions @nglish, !'rench,Germaa). A version iu aay other language made by traDslation uniler theresponsibility of a CEN member irto its own language and uotified to theCenhal Secretariat has the same status as the omcial versioDs.CEN members are the national standards bodies of Austria, Belgium,Denmark, Fidand, France, Germany, Greece, Iceland, Ireland., Italy,Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland andUrited Kingdom.

CENEuropean Committee for Standardization

Comit6 Europ6eo de NormalisationEuropriisches Konitee fiir Normung

Central Secretariat: rue de Stassart 36, B-1050 Brussels

@ 1995 All rights ofreproduction and communication ia any form and by aoy means reserved in allcountries to cEN and its members

Rei No. .uN 29b-?:1995 E

Vitrified clay pipes and fittings and pipe joints for drainsand sewers - Part 7: Requirements for vitrified clay pipes

and joints for pipe jacking

Tuyaux et accessoires en grds et assemblages detuyaux pour les r6seaux de branchement etd'assainissement - Partie 7: Prescriptionspour Ies tuyaux en grds et leurs assemblagesdestin6s au fongage

EN 295-7:1995

ForewordThis Europeao Staudard has been prepareil by theTechoical Committee CEN/IC I65, Wastewatrengireeriug, the secretariat ofwbich is held by DIN.The other Parts of this standard comprise:

- Part 1: Requirements;- Part 2: Qu.ality control ond. sompling;- Part 3: Test methods:- Part 4: Requirements for special fittings,odoptors ond compotible accessories;- Part 5: RequiremenB for perforated, vitrifizdclay pipes and. fittings;- Part 6: Requiremetuts for uitrificd claymanholes.

Thrs European Staudard shall be given the status ofa natioDal statrdard, either by publicatiou of aniilentical text or by endorsement, at the latest byApril 1996, and conflicting national stand.ards shallbe withdrawu at the latest by April 1996.In accoidance $.ith the CEN/CENELEC InternalRegulations, the following countries are bouud toinplenent this European Standard: Austria,Belgium, DenmarL, Finland, France, Germany,Greece, Iceland, Irelanil, Italy, Luxembourg,Netherlands, Norway, Portugal, Spain, Sweden,Switze and and the United Kiagdom.

Contents

Foreword1 Scope2 Normative references3 Definitions4 Pipes4.1 Materials and manufacture4.2 Measurement of dimeusions4.3 Minimum bore aod internal cliameter4.3.1 Milrimun bore4.3.2 Internaldiameter4.3.3 Invert coDfornity4.4 External diameter4.b Iaueth4.6 Squareness ofends4.'7 Deviation ftom straightness4.8 Strergth4.8.1 Crushi-ng strength (FlO4.8.2 Compressivestrength4.8.3 JacLirg strength4-8.4 Design jacking load4.8.5 Maximum working jacking load4-8.6 Bending teusile strength4.8.? Fatigue strength uDder

Page

5

555

55666666777777,7

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pulsatiug load 74.9 Watertightness ofpipes 74.10 Chemical resistance 74.11 Hydraulic roughness 74.12 Abrasion resistance 75 Joint assemblies 75.1 Joiuting materials 75.1.1 Rubber sealirg elements '7

5.1.2 Pol]'urethane sealiag elements 75.1.3 Staidess steel sleeves 85.1.4 Pollpropylene sleeve couplirgs 85.1.5 Materials ofother components 85.2 Packirg rings 85.3 WatertightDess ofjoints 85.3.1 Internal plessure 85.3.2 External pressure 85.4 Angular deflection 85.5 Sbear resistance 85.6 Chemical and physical resistauce

to emuent5.6.1 Joitrt assemblies

88

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EN 295-7:1995

Page5.6.2 Joiatirg materials 85.7 Thermal cycling stability 85.8 Long-term thermal stability I6 Sampliag I6.1 General I6.2 Compressive and jackiag strength I? Designation I8 Markiag I8.1 Pipes 98-2 Limitation 99 Quality assurance IAnaex A (normative) Compressive strength 1lAaaex B (normative) Calculatiou of maximumworkireg jackhg load 72Annex C (normative) Iuvert conformity 13Annex D (normative) Squareness of ends 15f igure B.1 - Relationship between stressratio omJoo aud ecce trictry rat;o Zlda 13Figure C.l - Invert coolormity(top markedpipes) 14Fi.gure C.2 - Iuvert conformity (randomlyjoiated pipee) 1.4Figure D.l - Gauge fot squareness ofends 15Table 1- Minimum bore . 5Table 2 - Tolerance on i-uternal diameter 6Tab1e 3 - Invert confornity 6Table 4 - Tolerance on external diameter 6Table 5 - Deviation from squareness ofencls 6Table 6 - Crushhg streDgths 7Table 7 - De{lection 8Table 8 - Applicable sampli-ug clauses 10

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1 ScopeTbis Part of this Duropean Standarcl specfiesrequirements for llexibly jointed vitrifecl clay pipesfor the coastruction ofpipelines by pipe jackingtechniques inclutling micro-tunnellilg, pipe-eatilg,pipe bursting and where appropriate for slip-liniug.Where tbis staDdard provides for different strengthclasses the specfiers/purchasers may selectaccording to their requirements.

2 Norrrrative referencesThie Duropean Standard itrcorpotats by dated oruntlated reference, provieions ftom otherpublicatious. These normative references are citedat the appropriate places in the text and thepublications are listed hereafter. For datedreferences, subsequent aneDd-Eents to or revisionsof any of these publications apply to this EuropeanStandard only when incorporated i.r: it byamendment or revision. For undated refereDces theIatest edition of the publication referred to applies.EN 295-1:1991, ,ified. clay pipes and fittings dnd.pipe joints for droitus qnd sewers -Part 1: Requirements.EN 295-2:1991, Wlrified, clay pipes and fittinEs qndpipe joints for d,rains ond, sewers - Part 2: QullitfControl and, sampling.EN 295-3:1991, Vtrified clay pipes and, fittings an

EN 295-7:1995

Nominal size

(D19

Tolerarce on statditrterDal diametcr

300400500

800> 800

+ 6+ 7,5

+ t 2

4.3.2 Intern aI di am ete rThe internal diameter ofthe barrel of a pipe shallnot deviate from the manufacturer's stated value byan anount greater than that shown iD Table 2-

Table 2 - Tolerance on internal diameter

4.3.3 Inuert confonnityWheD tested iu accordance with Aanex C for invertconformity, the difference in adjacent joiateil pipesshall not exceed the values given in Table 3.

Table 3 - Invert conformitv

4.4 Erternal diameterThe external diameter of the banel ofa pipe shallnot deviate ftom the mauufacturer's statedmaxinum value by an amount greater thaD thatshown in Table 4.

NOTE The external dismeter of the joint should not exced theextrDsl diametr ofjointed pipes foi pipes sEeater than DN 2254.5 LengthLengths ofpipes are not specified irr this standard.The tolerance shall be 4 2 mm on thenanufacturer's stated oomi:ral length.The length shall be measured at 90' intervalsarourrtl the circumfereDce. The toletance applies tothe meau of these measurements.4.6 Squareness of endsWlen tsted in accordauce with clause 2 of EN 295-3:1991 or Arurex D, the deviatioD from squarenessmeasuretl at the pipe ends shall be not greatel thanthe value given ir Table 5.Table 5 - Deviation from squareness of ends

4.? Deviation from straightnessWhen tested usirg a straightedge in the maximumbendiag plane, along the whole length ofthe pipebarrel which is oot affected. by jointirg or griudi.ng,the dewiation from straightness at the nid-poilltshall be uot creater than 5 om.'E

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Table 4 - Tolerance on external diameterNomiDal size

(Dl0

Tolerance on Etatede!ter|al diameter

300

400

500

800

I 000

0-10

0

0

o-18

0-24

0JO

NomiDal Eize(D|0

Idvert conformity

< 300> 300 to 3 600> 600 to < 800> 800

68

10

Nominal size

(Dl0

Maxturum deviatio! fromsquarensF

100 to 1 000 1

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EN 295-7:1995

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4.8 Strength4.8.1 Crushing strength (ItN)Wlen tested in accordance with clause 4 of EN 295-3:1991 the crushiag stlength (Fl| ofpipes or pipesectione shall be not less than the values given inTable 6 for pipes of noniaal siz DN 100 and DN150.

Higher crushing strengths may be dedaretl for DN100 orDN 150pipes, provided that the inmease is irsteps of 6 kN/m.The crushirg strength required for nomfual sizesgreatr than DN 150 shall be calculateil ftom theformula:

crushdne Bhenctb - class nu'ber x DN1000

(in kilonewtons per metre)Class numben are restricteal to 95, 120, 160and 200, ttrereafter in iucrements of40.1.8.2 Compressiue atrengthThe minimum conpressive streDgth whe!determiaed accordiag to Anaex A shall not be lessthan 75 N/mmz-4.8.3 Jaching strengthThe jacLiug strength shall be determiaed inaccordalce with Anner A.4.8.4 Design jacking load.Desiga jackiog load shall be declared by themanufacturer. This will ilepead on jackilg strcngthand on the specific aleeign of the joi-ut aod packirgrhg.NOTE The naximum wolLins jackiDs load l^'i be les than thedesign ia&ing load due to load eccntricity duins instslationand on any appl.ied factor of safety.4.8.5 Ma&imum working jaching loadThe maxiraum working loatl shall be determhedftom Alnex B and using factors of safety ofeither 1,6 fot autonatically steered jackingmachines ot 2,0 for malually steered systems.4.8.6 Bend.ing tensile strengthffiere whole pipes orpipe sectious are not availablea bendiDg tensile strength test in accordance withclause 5 ofEN 295-3:1991 may be carried out onbroken pipe pieces to determine the crushingstrength ofa pipe.

The crushi.ug streugth of the pipe shall be calculatedftom the mean bending teDsile strength ofat least10 test pieces.4.8,7 Fatigue sh'ength under pulsating loailVitrified clay pipes specfied i.tr this standard areresistantto fatig:ue from pulsating loads. Forspecialcircumstances of application the resistance tofatigue shall be verified by cyclic loading of2 > 106cycles with an equivaleut load varying between 0,1and 0,4 times the qushing strength of the pipe. Thespeciraens shall w'ithstand the test in accordatrcewith cl"ause 8 ofEN 295-3:1991 without failure.4.9 Watertightbess of pipeswlen pipes or pipe sections are tested iu accoralaDcewith clause 9 ofEN 295-3:1991 the water additionW15 needed to mahtai.D the plesule of 50 kPa (0,5bar) shall notexceed 0,07 Un2 ofiaternal pipe surface areawithout leakage for gravity pipelinesand 0,04 Vmz ofinternal pipe surface area withoutleakage for low pressure pipelines according to 1.1ofEN 295-1:1991.4.10 Chemical resist&nceVitrifi.eil clay pipes and fi.ttings specified in tlLisstandard are resistant to chemical attack. Forspecial circumstances of application the chemicalresistance may be determined by the use ofthe tstin clause 10 ofEN 295-3:1991.4.11 Hydraulic roughnessVitrified clay pipes and fittiDgs specified ia tlrisstandard have a low hyclraulic roughness. Forspecial circumstances of application the hydraulicroughuess may be verifred by use of the test inclause 11 ofEN 295-3:1991.4.12 Abrasion resistenceVitrified clay pipes and fittings specfied ia thisstandar:al are reaistant to abtasiou. For specialcircumstauces of application the abrasion resistancemay be determiled by the use of the test method inclause 12 ofEN 295-3:199i.

5 Joint assemblies5.1 Jointing materials5.L.\ Rubber sealinE elementsRubber eealiag elements shall be il accordance with3 .1 .1 o fEN 295-1 :1991.5.1.2 Polyurcthane sealing elementaPolyrrrethane sealing elements shall be irraccordance with 3.1.2 ofEN 295-1:1991.

Table 6 - Crushing strengthsNominal eize

(DN)Crushing strength (F}0

kN/m100150 28

3434

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5.1.3 Stoinle6s steel sleeveeThe corrosion resistance of stairdess steel shall beequal to or greatr thau the resistance of austeniticstainless steel with mininum chrome coutent of 17% and rninimum nickel contnt of 8 % from eitherTable 1c of Euronorm 88-1:1986 or Table lc ofEuronorm 88-2:1986 as appropriate.The sleeves sball be eilge dressecl and ftee fromsharp edges.When etaialess steel sleeves are butt weldetl, thewelds shall have firll penetration and be continuousacross the fulI width ofthe sleevesWtren fiIler metal is used for the welds, it shall becompatible with the stailLess steel sleeve material,and il compliance witb the recommendations oftbestainless steel sleeve material manufacturer.A.fter weldiag, oxides shall be removed.The iaternal surface ofthe sleeve shall be finishedto provide a sealiag surface.6.1.4 Pollprapflene deeue couplingePolypropylene sleeve coupliags shall meet therequirements ofEN 295-1:1991 as applicable.5.1.5 Materials of other componentsComponents of other materials which are used withvitrified clay jacking pipes shall comply with,insofar as these are available. the relevanttransposed European Staadarcls, DuropeanTechnical Approvals or the manufacturers' declaredspecfications, which shall also iacluderequirements for long term behaviour.5.2 Packing ringsParticle board packing riags where used betweenthe adjacent ends ofpipes shall consist of{loorirggrade particle board to prEN 312-4 or prEN 312-5.Other material used for packing riags shall be inaccordance with the pipe manufacturer's declaredspecification and correlated to particle boardpacking rhg design.5.3 Watertightqess of jointsNOTE For the pupoes ofioint tsting to the requirements of6-4,5.6,6.7 aDd 6.8 a ioint asEbly may be formed withoutpacking riogs.

5.3.1 Intenl al pressureJoint assenblies shall satisfu the requirementsof 5,4 and 5.5 wheu tested at iaternal pressures ofnot less than 5 kPa (0,05 bar) and 50 kPa (0,5 bar).5.i.2 E ternal pressureJoint assemblies shall satis$ the requirementsof5.4 and 5.5 when tested at exterDal pressures ofnot less thau 5 LPa (0,05 bar) and 50 kPa (0,5 bar)-

Table ? - DeflectionNomidal sire

DN

Mitrimum denecdon permtre ofdeflcted pipe

length

< 800> 800

2010

5.4 Angular deflectionOne pipe in a joiat assenbly shall be deflected bythe method described iu clause 18 ofEN 295-3:1991by the values in Table 7 and wheu sodellectpd shall withstaDd constant pressures of notIess than both 5 kPa (0,05 bar)and 50 kPa (0,5 bar) as specified ir 5.3 for 5 oinwithout visible lealrage.

5.5 Shear resistanceA joint assembly shall be tested by the Eetbodsdescribed in clause 18 ofEN 295-3:1991. Aaexternal load is applied to one pipe to proiluce ashear load at the joilt of Dot less than 25 N/mm ofnominal size.The joint assenbly shall withstand both constantpressures specified i.o 5.3 for 15 min wirhout visibleleakage.Joints passiag the t.est are considered to be resistantto root penetratloD.5.6 Chemical and physical resistance toeffluent5.6.1 Joint assembliesJoiat assemblies shaU be tested by the methodsdescribed in clause 20 ofEN 295-3:1991 using al1the test solutious specfied. A separate jointassembly shall be used for each test solution. Eachjoint assembly which has been exposed to oDe of thetest solutions shall withstand both the coustantintemal pressures specified in 5.3 for 5 min withoutvisible leaLage.5.6.2 J ointing m ateri al sClause 22 ofEN 295-3 gives a Detb;d ofdetermilirg the chemical resistance irdex (CR) ofjoiltiag materials for use ia pipes carrying efrluentswhich are more aggressive than uormal sewage.5.? Thermal cycling stabilityJoii:t assemblies shall withstaud cyclic temperaturechaoges between (- f0 * 2) oC and (+ 70 + 5) oCwithout visible impairment whel tested iraccordance with 21.1 ofEN 295-3:199I.Finally, a watertightness test as pecified ir 5.3'1shall be carried out.

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EN 295-7:1995

6.8 Long-term thermel stabilityJoint assemblies shall withstand a long.termtbermal stability tst in accordance with 21.2 ofEN 295-3:1991for 7 days at a temperatureof 45 +f 'C.

Fhally, a watertightDess test as specified ia 6.3.1shall be carried out.

6 Sa:rrpling6.1 GeneralSampliag is specified in EN 295-2, in wbLich theepecification clause numbers refer to EN 295-1.Table 8 gives the cross-refereace between therelevaut coresponding clauses ofprEN 295-? aodEN 295-1, anil the applicable EN 295-2 clauseDumbers.6.2 Compressive and jacking strengthSampliag for 4.8.2 and 4.8.3 shall be in accordancewith Annex A-Tlpe tests shall be carried out at iltervalsof6 months on samples cut from one pipe of eachnominal size produced iluring theprevious 6 months.

7 DesiguationThe followiag shall be used for the designation ofpipes for treuchless construction:

Block 1 DescriptionBlock 2 EN 295-7Block 3 Iudividual item block

3.1 Nomiaal size3.2 Crushing strength3.3 Design jackirlg load

8 Marking8.1 PipesAll pipes shall be marked with:

a) EN 295-7;b) CE mark (to be added after confrmation oftheEC Council Regulation on the use ofthe CEmark);c) identfication synbol of the third par$certfication body;d) maDufacturer's ideltitrcation.e) clate of mauuiacturi.ng;D nomhal size @N...);g) crushiog strength i! kilotrewtoDs per metre;h) desieD jacking load desigration.

This marking shall preferably be irnpressed beforefirirg, or, if this is uot possible, shall be hileliblydone after 6ring on each pipe.8.2 LimitationPipes shall be marked with the oumber of thisstandard only if certifietl in accordance with clause9 by a third party certificatiou body.

9 Quality assuranceQuality assurance shall be in accorclarce with 4.2and EN 295-2:1991.

EN 295-? - DN 160 - IN28 - 800

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EN 295-7:1995

Table 8 - Applicable sampliug clausesRquiremDt ID accordance with

this giandardIn accordance with EN

296-1:1991In accordadce *ith EN

295-2:1991

Mirdmum boreInternal diameterInvert conformityExterual diameterLengthSquareness of endsDeviation &om straightuessCrushing strengthCompressive shengthJacking strengthBending tensile streugthFatigue strengthWatrtightness of pipesChemical resistauceHydraulic roughness

lAbrasion resistance

I Rubber sealir8 elements

I Watertightness of joiltst_ .I ror]'uretxane seaulg eremeDts

I Polypropylene sleeve couplingslAneular deflectionIlShear

resistance

I Cheroical and physical resistance

I Thermal cycling stabiliwI Iong-term thermal stability

4.3.14.3.24.3.34.44.64.64.74.8.14.8.2 (see 6.2)4.8.3 (see 6.2)4.8.64.4.74.94 .10

14.1rla:r-I15 .1 .1lu ' t15.1 .2ls.r.nt::t::t::l o . tI s.s

2.102.132, t42.152,L6

12.r713.r.113.2.r13 .1 .2

l::'l " ' "P.'l r ' tl r ' tt 3 . 9

2.42.62.9

3,2

3.13.3

s.23.2

;3.4

| 3 .3It 3 . 4I13 .4t " ,

l " ' , '13.r313 .10I

13.e.3I 3.1313.1313.1313.r3.3It 3 . 1 3 . 3

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EN 295-7:1995

Annex A (normative)Compressive strengthA.1 Test rnethodsL.l.l Testing machineA compressive testing machine shall be usecl,equipped with a means ofproviding the rate ofload.ing specified h A.1.4 and with a pacirg device.The capaciw of the machiae shall be such that theexpectd ultimate load on a specinen is greaterthan one-fifth ofthe machine scale range. Thetesting machiae loail ghall be verified by calibrationto an accuracy of 1 % by an apppovecl agelcy atiltervals of not more thaa 12 months.The machi.ne shall be equippecl with two pernaneutferrous bearing platene which shall lre at least a6large as any plywood packi.ng or, where suchpacking is not beiag used" the bedding faces ofthespecimen being tested.The upper machine platen shall be able to alignteely with the specimens as contsct is made but theplateas sball be restrained by fiction or othermeans iom tiltirg with respect to each other clurirgloading.The lower compression platen shall be a plain, oontilting bearing block.The testing face of the platens shall be hardenedand shall have a flatness toleranc of* 0,05 mm.The machiae shall be substantial and rigidthroughout, so that the distribution of the load willnot be afrected by the deformati.on or yieldi-ug of auyPart.A.1.2 Preparatian of epecimensSpecimeas shall be preparecl accordiag to one ofthefollowiag procedures.

a) As cubes and with mi:rimum length of sideof 14 mm cut from the pipe wall with the opposirgfaces which are to be i! contact with the platensofthe testi.ng machi-ue grounil parallel and planeto a toleraoce of* 0,50 mm.

--

b) As cylinders, cut parallel to the longitudiralaxis of the pipe. They shall have a minimumdiameter of 14 mm and their length shall bebetween l and 1,5 times the diameter. They shallhave flat top anil bottom faces which are to be incontact with the platens ofthe testing machine,ground parallel andplane to a tolerance of+ 0,50mm.

c) As sectors ofthe pipe wall, cut parallel to theloagiturli.ual axis ofthe pipe- The tbickness shallbe that of the pipe wall and the width measuredaround the outr cicumference ofthe pipe shallbe approxinately the same as the wall thickness.The length shall be between 1 and 1,5 times thethickness. They shall have flat top and bottomfaces which are to be iD contact with the platnsof the testiag machiae, Sround parallel and planeto a toleraDce of+ 0,50 mm-

Samples shall be pre-contlitioned in water asdeecribed in 4.1.1 of EN 295-3:1991.The manufacturer shall decide on the shape of thesample, either a),.b) or c) ae given above.A-1.3 Teat pmcedureWipe clean the bearing surfaces of all the platensanil remove any loose grit or other material from thesurfaces of the specimen which are to be in contactwith the platens.To ensure a uniform bearilg for the specimeu, placeit between plywood sheets to take up irregularities'The plywood shali be tbree-ply, nomiually 4 nmthick, ofEuropeau birch or softwood ancl ftee ftomknots. Ensure that the plywood exceeds thespecimen size ilimensions by 5 mn to 15 mm. Use aftesh pair ofpl1'wood sheets for each tst.Place the epecimen centrally uocler the loadiagpoint of the upper platen ir such a way that theapplied load compresses it in a clirection parallel tothe longitudinal axis ofthe pipe..!-L.4 laadingApply the Ioarl without shocL ancl increase it at acou.renient rate not exceeding 35,0 N rom-2 -in-rup to half the aaticipated maxinum load.Thereafter smoothly change the rate of loadingto 15,0 N nm-2 uin-l aud maintain tbis rate uotilfailure, i.e. when the indicator neeille falls back iospite ofprogtessively adjustilg the machinecontrols or the specimen undergoes explosivecollapse.NOTE A higher rat of loadhg up to half the m3rimum Ioadreduces the time for testing the specimen and mav be usedbecaus th rate oiloading during this 6tage does not influencthe ultimat 6treDth.Record the maximum load (ia newtons) carried bythe specimen clurirg the test.From the maximum load carried by the testspecimeu ald the area of the specimen i! contactv,rith the pb'wooil facings, the compressive strengthofthe speciuea is calculated in uewtons per squaremilljmetre. The contact area is deternined as themeasurerl mean of the two opposing faces.A.2 Calculation of compressive and jackingstrength

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EN 295-7:1995

The compressive strength of the clay body shall becalculated ftom the meau compressive streDgth ofatIeast 10 specimens cut ftom the same pipe,The miaimum compressive strength is calculated bydeducting 2 times the stauilard deviation of ttresample from the mean value.The milliDum annular area i.n square millimetresthrough which the jackiag forces act is calculated.This may be locatecl at the base of any gtooveholdiag the joint sealing ring or at the packing ring.'Itie area isr/4 (d.^2 - diz) where d, is the minimumoutside diameter and di id the maximum iuterDaldiameter at the minimum cross sectio[.The jackirg strength of the pipe shall theu becalculated i|l kilonewt4ns by multiplyiDe thenirimum compressive strength calculated inneEtons per squars millimstrs !y 1[s minimumannular area and iliviili.ng by 10r.A.3 RetestIfthe minimum compressive strength of a samplefails to comply with the requienent of 4.8.2 theretst procedure as 3.13.2 ofEN 295-2:1991shall becarried out.

Annex B (normative)Calculation qf rne

EN 295-7:1995

--r+-

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10

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0 02.01 q4 0,s 06 0,7 0,8z*

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Figure 8.1 - Belationship between stress ra.tio d and eccentricity ratio

Annex C (norrnative)Invert conformityC.1 Test methodsFor pipes which are marked to show the top of thepipe, the test method giveu ill C.2 shall be used.For pipes which are not marked to show the top ofthe pipe, the test method given in C.3 shall be used.

C.2 Pipes with top markingThe difference iu irvert levels D' forjoint assembliesshall be determined using ilimensions o"o and 6"o(see Figure C.1):

d " = o " o - b " n

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EN 295-7:1995

C.3 Pipes randomly jointedC,3.1 Sompling and. d.imensiontSelect 20 pipes at random. For each pipe measurethe folowing at a random position(see Figure C.2):

- the outside diameter ofeach spigot, 4, aail, atthe sane positiou, the distance ftom theoutside diameter of the spigot to the internalbore ofthe pipe on troth sides, B; and C1;

- tbe internal diaEeter of each spigot on towhich a sleeve joint is fittd at the factory, D,and, at the same position, the distance &omthe outside diametr ofthe spigot to theinterDal bore of the pipe on both eides, E1 audFL.

C.8.2 Deriued ualuesI'rom the mean values ofA and D (A- anrl D-respectively) the mean annular gap G. will becalculated as

G^= 712(Dg - A).This value will be either positive or Degative.

From the combhed values ofBl and C1 aud E1 andF5, the mean (,B1 and C)* and (81 and F). and theconespondirg standard deviations will becalculated:

S(t, ana cJudSrr, ara 4lQ.3.3 CslculationsThe mean difference ir iavert S- is

S- = (.B, and C)- + G- - (8, and F)^The combined standard deviation 51 of the values(Q and C) and (81 and F) is

S, - [521r ana c,) + 9ls, ^oa r,)]h

The extreme values (5 % and 95 % fractile) for thedifferenc in ilvert are

S.i,, = S. - 1,68 StS-,* = S- + 1,68 51

C.3.4 EoaluationNone of the calculated values (56,,; S^"") shall behigher than the values ir 4.3.3 for the romilaldiameter which is che*ed.

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Figure C.l - Invert conformity (top marked pipes)

Figure C.2 - Invert conformity (randomly jointed pipes)

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EN 295-7:1995

Annex D (normative)Squareness of endsD.1 Test methodThe pipe shall be placed on a horizontal support.The gauge sball be clamped to the ground ends ofthe pipe. The pivot arm is locatedapproximately 100 mm away from the cut end.

D.2 MeasurementThe distance between the pivot arm and the cut endis measured at 90" intervals.The deviation ftom squareness is the difierencebetween the maximum ald minimummeasurements.This procedure shall be performed for both ends ofthe pipe.

Nev30 GauSe31 Clamp32 Support33 Caliper Sauge34 Pivot arm35 Spirit level

Figure D.1 - Gauge for squareness of ends

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@ BSI 09-1999 l 5

BS EN 295-7:1996

National foreword

This Part of BS EN 295 has been prepared by Subcommittee 8/505/2 aud is theEnglish language versioa of EN 295-7:7995 Wtrifiecl clay pipes and. fittings andpipe joints for d.roins and. sewers - Part 7: Requirements for vitrificd, clay pipesand. joints for pipe jocbing, published by the European Conmittee forStandardization (CEN). This European Staudard was prepared by WorLiagGroup 2, Vitrifieil Clay Pipes, of Technical Committee CENIIC 165, with theactive participation and approval ofthe UK.

Cross-references

Publication rferred to Corresponding British StandardBS EN 295 Vtrnlrd clay pipes and fittings and pipejoitrt, for drains ond seuer,

EN295-1:1991 Part1:l99TEequirementsEN 295-2:1991 Part 2:1991 Qualit! control dtud samplingEN 295-3:1991 Part 3:1991 Test methadsDN 295-4:1995 Pafi 411995 Requirements for speci.