Ideas at Work ROVAI User manual

THE‘ROVAI’ PONDPUMP-RP6
(TheCambodianversion oftheRopePump)
OPERATIONAND
MAINTENANCEMANUAL
V. Whitehead, March2008
Ideasat Work(IaW)
#5,Street21,
TonleBassac,
Phnom Penh
Phone
:[phone]
Mobile:[phone] (Khmer)
Mobile:[phone] (Eng)
Email: [e-mail]
Web: www.ideas-at-work.org

IdeasatWork/PondpumpO&Mmanual/Rev1/ Mar08/EngPage2of17
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Introduction
Thismanualhasbeenproducedtohelpthepumpcaretakertocarryoutbasic
maintenance and repairs. Byfollowing theinstructionsinthismanualitwillhelpto
ensurethatthepumplastsaslong aspossiblewiththeleastamountofproblems.
ThisRovaipond pumpmanualmayalsobeusefultovillagechiefs, waterusergroup
staff orprojectmanagerswhensetting operation and maintenancetraining forpump
caretakers.
Contents:
ThemaincomponentsoftheRovaiPondpump....................................................................................3
Operatingthepondpump..........................................................................................................................3
General maintenance &care .....................................................................................................................3
Cleaningthepump.......................................................................................................................................3
Checking theropecondition and thatitisadjustedcorrectly........................................................................3
Howtotietheknotintherope......................................................................................................................3
Changing theropeandpistons.................................................................................................................3
Changingaropethatisworn.......................................................................................................................3
Replacingaropethathasbroken.................................................................................................................3
New pistons..................................................................................................................................................3
Care ofthepaintwork..................................................................................................................................3
DetailsofRovaiPondPump
PumpNo.:……………………………………………………………………….
Dateinstalled:……………………………………………………………………

IdeasatWork/PondpumpO&Mmanual/Rev1/ Mar08/EngPage3of17
8
10
9
11
12
ThemaincomponentsoftheRovai Pondpump
1.Wheel cover
2.Wheel
3.Handle
4.Cementcover
5.Adjustablepipe
clamp
6.Pumpframe
7.Protectionpipe
8.Rope&pistons
9.Ceramicguide
10.Outletpipe
11.Upperguidebox
12.Framebolts(x4)
6
5
1
3
2
4
Figure 1MaincomponentsoftheRovaiPondpump'supper parts
7
Figure 2DetailsoftheRovaipond pump’soutletassembly

IdeasatWork/PondpumpO&Mmanual/Rev1/ Mar08/EngPage4of17
13.Float
14.Strainer
15.Inletpipe
16.Flexiblerubberjoint
17.Elbowand reducer
18.Bottomguidebox
19.Riserpipe
20.Returnpipe
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TheRovaipond pump
The Rovaipondpumpisdesignedtolift waterfromsourcessuchasponds, lakesandvery
slowmovingrivers.Thepondpumpissimilartothe standardRovai(usedonhanddug wells
andtubewells)andusesmanyof thesameparts,but therearetwodistinctdifferences:
•theriserpipesarefitted insideaprotectionpipe and that thiscan beangled tosuit
thepondorriverembankment, and
•It hasafloating strainerwhichonlyallowswaterfromthetop of the pondtoenterthe
riserpipe. The wateratthetopof the pondisusuallytheleast turbid.
When thepumpisoperated waterenterstheintakepipe throughthestrainer.Thestrainer
preventsleaves,small fishorotherdebrisfromgettingintothepipes.
Asthe waterlevelinthepondchangesoverthedryandwet seasonstheflexiblerubberjoint
allowsthe float toriseand fall withthe waterlevel.Sothewateratthetop ofthepond is
usedthroughout theyear.
Figure 3Cutaway viewofinletassembly
17
14
15
16
13 20 19
18

IdeasatWork/PondpumpO&Mmanual/Rev1/ Mar08/EngPage5of17
Spares/toolskit
A‘spares/toolkit’isavailablefromthemanufacturesof the ‘Rovaipumps’. It isrecommended
that oneof theseismadeavailabletothepersonresponsibleformaintainingthe pump.
Belowisalistof itemsthat will beneededhelpmaintainthepump,
§Sparerope–approximately30m
§Sparepistons-approximately26 pistons
§No. 6’’ adjustableSpanners: -2spanners
§PVCglue–small tube
§Sandpaper–1sheet
§Thinstring &weight (fishing line)-approximately24mlong
§Oil -small containerapproximately100ml
§Cigarettelighter(forburningendof rope)
§Ø34mm PVCstraight connector–1pieces
Ifthe itemsaboveareused upormaybelost, makesurethesearereplacedassoon as
possible. Thiswill makesurethat the pumpcan berepairedquickly.
Operatingthepondpump
The pondpumpisoperatedbyturningthe
handleinaclockwisedirection.
Thisrotatesthe wheelwhichmovestherope
insidethepipe. The pistonsfitted totherope lift
thewaterupthepipeandthisflowsoutthrough
theoutletpipe.
The handleshouldbe turnedat about1
revolutionpersecond. Ifthehandleisturnedat
alowspeedtheflowofwaterwill below, ifthe
handleisturnedfasterthe flowofwaterwill be
greater.Turning thehandletoofastisunlikely
todamagethepumpbutthisputsstress on the
ropeand maycauseittostretchwhichwill
maketherope loose.Soavoidturning ittoo
fast.
Amechanismisfittedtothe pumpwheeltoprevent thewheelfrombeingturnedinthe wrong
direction.

IdeasatWork/PondpumpO&Mmanual/Rev1/ Mar08/EngPage6of17
General maintenance &care
Therearefourbasicmaintenancepointsthat needtobecarried out. 1)Keepingthe pump
clean, 2)oilingthe handle3)makingsuretheropeisingood conditionandthat it iskept
reasonablytightand4)checking andcleaningthe intakeandprotectionpipe.
1)Cleaning thepump
During operation ofthepumpsomewaterwill
be sprayedoff the wheelandontothecement
cover,theplasticpipesandthepumpframe.If
thewaterisleft indirect sunlightagreenalgae
will naturallydevelop.Althoughthisisunlikelyto
affect thepumporcontaminatethewaterit
shouldnot beignored and lefttogrow.
Astiff brush(notsteel)andacleanclothshould
be usedtoremovethealgae fromthecement
cover,theplasticpipesandthepumpframe
eachweek.
2)Oiling thehandlebushes
Applying oil tothebushesmakesitmucheasier
toturnthehandleand thebusheswill notwear
asquick. Thisshouldbedoneregularlyeach
weekandwill makethe pumplast muchlonger.
The oil holescanbefoundonthehandle
bushesateitherside ofthewheel.
Applysomeoil totheseholesbyusingasmall
oil canasshownorbydipping athinpieceof
wireintosomeoil andthenlettingafewdrops
enterthe holes. Useacleanragtowipeoff any
oil thathasspilledorrunontothe frame.
Always useclean oil ratherthanoldengineoil
Ifthe pumpsqueakswhen youturnthehandle
you knowthatit hasnot beenoiled!
3)Checkingtheropecondition and thatitis
adjustedcorrectly
Check therope atleastonceamonthtoseeifitis
showingsignsofwear.
Todothisturnthehandleuntil the knot can be
seenbelowthewheel. Thenslowlyturnthehandle
andlookat thefull lengthof the rope,andstop
whentheknot comesround again.If theropeis
frayedevenslightlyarrange forittobechanged
(see Section3onhowtodothis).
NOTE: it ismucheasiertoreplacearopethat is
still working,but worn,thanone thathasbroken
andfallendownthepipes!! Socheckthisfrequently.
Oil in2places

IdeasatWork/PondpumpO&Mmanual/Rev1/ Mar08/EngPage7of17
Check toseeiftheropehasthecorrecttension.
Todothispull upandpushdownontherope
lightlyasshownbythearrowsopposite. There
shouldbearound2-4cmofmovement.
Ifit ismorethan4cmturnthehandletofindthe
knot. Untieitand takeouttaketheslackoutof
theropebygentlypullingeachend oftherope,
re-tiethe knotagainasshownbelow.
Ifthe ropemovesless than2cmthenthe ropeis
tootightandthiswill makeit stiffandit wont be
easy toturnthe handle.
How totietheknotintherope
Followthe fivestepsasshownbelowfortyingaknotintherope.Afterstepfivepull therope
tightand check that it will not comeundonebypulling hardoneachsidetheknot.
STEP1 STEP2 STEP3 STEP4 STEP5
NOTE: Aftercutting theendsburntheendsof theropewithasmall flametostop themfrom
fraying. Makesuretheropeisdryfirst!
4)Checkingand cleaningtheintakepipeand protection pipe
At leastonceayearthe protection pipe andstrainerwillneed removing fromthe
watertocheck if thereisabuildup of sediment in
the pipes. If thereissediment insidethiswillneed
tobe cleaned out. If thewaterisverydirtythis
mayneed doing moreoften.
1)Removethe fourscrewsfromthe cornersof
the wheelcover(1)
2cm
1

IdeasatWork/PondpumpO&Mmanual/Rev1/ Mar08/EngPage8of17
2)Turnthehandleuntiltheknotinthe rope isat
the top of the wheel. Untiethe knotropesand
pullthe ropestothe side.Looselytiethese
togethersothat theydon’t slipdowninside the
riserorreturnpipes.
3)Removethe screwsholdingthe pipe bracket
(1)andthe protection pipe clampscrews(2)
4)Removetheoutletpipeandgentlylowerthe
protectionpipeand upperguideboxdown
throughthe clamphole. Thearmsoftheclamp
framecanbeopenedtodothis.
5) usingatleasttwopeopleslowlypull the
protectionpipeoutofthewaterandrestthe
intakeendonthecementcover.Putthe
upperguideboxend onacleanareaof
groundpreferablywithsomeplasticsheetsto
keepthe pipesandropeclean.
1
2
1.5m

IdeasatWork/PondpumpO&Mmanual/Rev1/ Mar08/EngPage9of17
6)Removethe reducercapfromthe bottom
end of theprotection pipe.
7)unscrewthe end of the strainerfromthe
bottomof the intakepipeand washitin
cleanwater.
8)Pourenoughclean waterdowninside the
end of theintakepipe toflushoutany
accumulated sediment.
9)Pourenoughclean waterdowninside the
end of theprotection pipe toflushoutany
accumulated sediment.
10)Wheneverything iscleaned out the intakeandprotection pipe willneed putting
back inthe reverseorder, sodo thefollowing:
a)replacethe upperguide boxon totheprotectionpipe,
b)re-fit the straineron tothe end ofthe intakepipe,
c)pushtheelbowand reducerback onthe bottomof the protection pipe,
d)lowerthe protection pipe backintothe water,

IdeasatWork/PondpumpO&Mmanual/Rev1/ Mar08/EngPage10of17
e)pushthe upperguide boxup throughthe adjustableclamparms.
f)re-fit the rope back throughthe outlet assemblyand looselyaround the wheel
g)fit the clampscrewstothe pipe bracket andclamparms
h)pulltheropeuntilthereisaround2cmof slack inthe rope then tieaknot as
shownon page 7
j)Slowlyturnthehandletocheck that the ropeisfree tomoveallthe way
throughthe pipe.
h)finallyrefit the wheelcoveron the pumpwiththe 4screwsand nutsoneach
cornerback

IdeasatWork/PondpumpO&Mmanual/Rev1/ Mar08/EngPage11of17
Changingtheropeandpistons
Thissectioncovers1)changingaropethat iswornand2)removingaropethathasbroken
andfallendowninsidethe riserorreturnpipes.
Changing aropethatisworn
Prepareanewlengthof 5mm diameterropeinadvance–around 30mshouldbelong
enough
1.Takethewheelcoveroff byremovingthe
fournutsandboltsateachcorner(1).
2.Turnthehandleuntil theknotcanbe seen
at thetopofthewheel.Untiethe knot then
tiethe endthat comesout of theriserpipe
tothefront coverframe(2)tostop itfrom
fallingback downthepipe.: Tieon anew
pieceof rope (3)ontothe end that leads
downintothereturnpipe.
Ifasetof new pistonsaretobe fitted then
thesecanbeaddedtothe newropenow.
Ifthisisdonepull thenewropethrough
andfollowinstructionsfromstep6below,
checkthatthepistonsarefacingtheright
way.
3.Ifthe pistonsarestill ingood condition
thesecanbeusedagain.Simplyremove
themfromtheoldropeoneatatimeand
tietheseon toanewpieceofropeas
shownbelow.
Ifnewpistonsareneeded thesecanbe
addedtothe newrope.
4.Tietheoldpistonsonwithtwoknots,one
aboveandonebelowthepiston. The
pistonsshouldbeplaced1mdistance
apartfromthenextpiston.
Makesureall the pistonsfacethesame
way.
1
3
2
1m
4newropewitholdpiston

IdeasatWork/PondpumpO&Mmanual/Rev1/ Mar08/EngPage12of17
5.Beforetyingthe ropestogetherpull oneach
ropetocheck that it isfreetomoveinsidethe
pipesandthat itisnotcaughton anything
insidethepipesorguide box. Wraptherope
aroundthewheeland threadit throughthe
guidepiecesasshownopposite. Allowsome
overlapandcut off anysparerope. Tieaknot
intheropeasshownonpage7.
Don’tforget -don’t maketheropetootight.
Carefullyturnthe handleslowlytocheck that
theropeandpistonsarefree tountil water
comesout of the outletpipeandthat the flow
rateisacceptable.Finallyre-fit thewheel
cover.
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Replacing aropethathasbroken
Ifthe ropehasbroken andfallendowninsidethepipesthenthe riserpipeandguideboxwill
havetoberemovedfromthe pond. Followthe stepsanddiagramsbelowtoremovethe
pipesandtofitanewrope.
NOTE: someropesdo not last aslong asotherssotrywhereverpossibletobuyropesimilar
totheoriginalfactoryfittedrope.
Makesurethat thefollowingtoolsandmaterialsareavailablebeforestarting therepair:
Tools:
•2xadjustablespanners),
•Alighterormatches(toburntheend of therope)
•Athinstring e.g.fishingline, withasmall weight attachedtooneend (todropdown
thepipeandpull the newropethrough)
Materials:
•Anewrope fitted withpistons(unlessthe broken ropecanbe refitted)
1.Takethewheelcoveroff byremovingthefour
nutsand boltsat eachcorner(1a)
1a

IdeasatWork/PondpumpO&Mmanual/Rev1/ Mar08/EngPage13of17
2.Removethetwoscrewsonthetoppipe
bracket (1)andremovethetwoscrewsfrom
thebottomclampthatholdsthelarge
protectionpipe(2)onatthefrontandoneat
theback ofthepipe.Keepthe screwsina
safeplace!
3.Removetheoutletpipeandgentlylower
theprotectionpipeandupperguidebox
downthroughtheclamphole. The armsof
theclampframecanbe openedtodothis.
4.Pull the protection pipetothesideof the
Rovaipumpandgentlyremovetheriser
andreturnpipesoutof theprotectionpipe.
Puttheriserandreturnpipesonaclean
areaof groundpreferablywithsome
protectionlikeplasticsheetstostopsand
particlesstickingtothepipesorguidebox.
a.Removetheoldropethenusea
pieceoffishingline about30mlong
withaweightontheendanddrop
thisdowntheriserpipe(largesthole
intheupperguide box).
1
2

IdeasatWork/PondpumpO&Mmanual/Rev1/ Mar08/EngPage14of17
5.When theweight onthefishinglinecomesout
ofthebottomendof theriserpipewrapit round
thewhiteceramicguide. Thendrop theweight
downintothereturnpipe(1)until itcomesout
ofthetopendof thereturnpipe(2)asshownin
thediagramopposite.
6.Attachthenewropewithpistonsontothe
fishinglinethatgoesinsidethesmall flared
returnpipeoftheupperguidebox.Thesmall
conesideofthepistonshouldbefacing
towardsthe flaredpipe. Pull on thefishing
line topull the newropethrough–makesure
thepistonsareabout1mapartand all facing
thesameway.
7.When thetwoendsof theropearelevelwith
eachotherremovethefishingline fromthe
newrope. Thentietheendsofthenewrope
togethertostopthemfromfalling downinside
thepipes.
8.Refit thepipesintotheprotection pipeby
loweringthebottomguide boxintothepipe as
shownopposite.
1
2
Tietwoendsof
ropetogether
Tieonnew
ropewith
pistonson

IdeasatWork/PondpumpO&Mmanual/Rev1/ Mar08/EngPage15of17
9.Re-fit the upperguideboxassemblyontothe
endof the protection pipe(donot putglueon
it).Withtheropeendsstill tied togethercheck
that the ropewill pull through theriserpipe
withoutgettingstuck orbeingtight.Keep
pullingthe ropeuntil thetiedendsof therope
appearagain.
10.Pull the clamparmsapartslightlyandpush
theupperguideboxandprotectionpipeback
on tothesmall pieceofpipeonthe well cover.
11.pushthe ropethroughthe outletpipeandpush
theoutletassemblyintothe upperguidebox
assembly.
12.Re-fit thepipebracket withitstwosmall
screwsand nuts(a).Alsorefitthescrewsthat
clamptheprotectionpipeatfront andback
(b).
13.Pull the ropeandthreadit roundthewheelas
shownthentiethe twoendstogetheras
describedonpage7.
a
b

IdeasatWork/PondpumpO&Mmanual/Rev1/ Mar08/EngPage16of17
14.Re-fit the wheelcoverandfoursmall screws
on eachcornerof thecover(1).
Carefullyturnthe handleslowlytocheck
that the ropeandpistonsarefreetomove
throughthe pipe. Increasethe speeduntil
watercomesoutoftheoutlet pipe and that
theflowrateisacceptable.Thenre-fitthe
wheelcover.
Don’tforgettotidyup around thewell afteryou
havefinished…
…Itdemonstratesyou care!
New pistons
The pistonsaremadefromstandard21mm PVCscrewedend capsandcanbe boughtfrom
most hardwareshopsat localmarkets. Theseareshownbelow…
The 21mm PVCscrewedendcapsaremadeintoRopePumppistonsbygrinding(or
cutting)thesidesof the endcaptotheshapeand sizeasshownbelow. It issuggestedthat
you usealocalworkshopthathasthe equipmenttohelpmakethese. Takeasetof26new
PVCendcaps(asshowninfigure4),asmall pieceof the rope,asmall section oftheriser
pipeand asampleof the oldpiston totheworkshopsothattheycanmakethe pistons
correctly.
Figure 4standard21mm PVC screwedendcaps (topand bottomview)
Figure 3Modified21mm PVC screwedend caps (topandbottomview)
20mm
20mm
6mm
Ø6mm
28.5-29mm
1

IdeasatWork/PondpumpO&Mmanual/Rev1/ Mar08/EngPage17of17
NOTE: Thereshouldbe agapof around0.5and1.0mm betweenthepistonandtheinside
diameterof theriserpipe.Ifthegapistoobig, waterwill passdownaroundthe piston and
theflowofwaterwill beless than itshouldbe.Ifthegapistoo small thepistonsmaybe tight
insidetheriserpipe, thiscan makeit stiff toturnthehandle.
Careofthepaintwork
The frameworkwill eventuallyget scratchedthrough normalusage. Ifthisisleft itwill soon
becomeanareawhererust will appear.
Tohelpminimisethisrubanyrustyareaswithsandpaperandwipewithacleandrycloth.
Applyacoatofpaint totheareaandleavetofullydrybeforeoperatingthepump.
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Thismanualshouldbe keptinasafeplacewiththe person responsiblefor
takingcareof thepump.
If asparesbox, ortoolbox, hasbeenpurchased forthe pumpthismanual
shouldbe keptinside that boxaswell.