Andhowwecancontrolit!ChaosinDrainagePipesBetweenWaterandAirElementsindrainagesystems-WaterSolidsWaterAir-Air-SolidsUderpressureP+P±0P±0P-OverpressureIdealSituationintrapshP±0P±0Under/OverpressureinTrapsUnderpressure

p±0p-p-p+p±0Overpressure

4.0mMaximallengthofsitebranchconnection4metreCausesofpressuredifferenceshdAirWaterRatioofFillingHeighttoDiametreh/dhdAirWaterMutualsiphoningoftrapsealsP-P+Pipinggeometry-bends

Self-Siphoningp-SelfSyphoningflowfunction

Underpressure

P-

P-SiphoningthroughanotherfixtureP-P+SyphoningthroughanotherfixtureUnderpressure

P-

WashbasinconnectorwithInternal

Diametre

(ID)42

ID=Internal

Diametre

ID42,thehorizontalpipeiscompletelyfilled,

thewatersealissiphonedoutID=42mmID50,thehorizontalpipeisnearlyhalf-filled,

nosiphonageofthewatersealdoesoccurID=50mmWashbasinconnectorwithInternal

Diametre

(ID)50

Overpressure

P+P+P+ResistanceResistanceduetobendsandlongpiperunP+P+incorrectP+P+2mcorrectP+-0Overpressure

P+incorrectConnectiontothestackBranch45°,reducedAircirculationblockeddueto

waterplugBranch881/2°,reducedFreeaircirculationFreeaircirculationConnectiontothestackBranch881/2°,equalSweptentry881/2°FreeaircirculationFreeaircirculationHydraulicclosureaircirculationblockedFreeaircirculationBackupofwatersealOverpressureSelf-siphonageofwatersealCompletelyfilledpipe=underpressureUnderpressureSiphonageduetounderpressureinthestackConnectionto

thecollectorpipeTopviewElevationHorizontalVerticalSoildepositsarewashedintothebranchConnectionatthesamelevelConnectionintheupperhalfWatercannotenterthebranchHorizontalVerticalConnectionintheupperhalfBackflowinhorizontalpipes

Quantityofbackflowwater=

X3.3l/s2.0l/s3.3l/s3.93l/s0.17l/s2.19l/sSwept-EntrySwept-Entry88,5o45o88,5o45oDonotuseSewpt-EntryfittingsasbranchcollectorpipesConnectiontocollectorpipeVerticalInletHorizontalInletConnectiontocollectorpipe45°InletfromaboveAircirculationshouldnotbeblockedduetowaterenteringthemaincollectorpipeAvoid

waterbackflowintobranchesReducers,concentricandeccentricconcentriceccentricNobackflow!RecommendedSolutionBackflow,possible.Backflow,incorrect.AirAirAirWasserWasserWasserBacktobackapparatusesHorizontal45

offset.Nobackflow!Horizontal.BackflowfromonefixtureconnectiontoanotherVertical.Nobackflow!CorrectIncorrectCorrectAirtowaterratioinstacks75169264529CrosssectionalAreaVolumeofwaterWater-AirmixtureWaterAirVelocityofwaterflowinst