Van't Woudt, Bessel D., 1913-

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TECHNICAL PROGRESS REPORT NO. 1,10 OCTOBEH 19MA Zippered - Pipe Principle forIrrigation Water SupplyBESSEL D. VAN'T WOUDTHAWAII ACIUCULTUHA L EX PEIUI\IENT STATIO \ UNIVERSITY OF HAWAIITEC. HN ICA L PROGR ESS R EP ORT NO. 140 J U N E 1% ,1II AWAII AGBI CULT liB AL I~XPElmll; : NT STA T IONCOLl"~G I<: 010' THOPICAL AGIUCULT lJHI<:UNI VI':BSIT Y OF IIAIVAIIl lo uo lu lu , lI a waiiA Zippered - Pipe Principle forIrrigation Water SupplyBESSEl D. VAN'T WOUDTINT HOI)UC'1'I0 NA fe w ye ars a go t he lI awa ii Ag r icu lt ura l I'; xp er inle nt S ta t ion re c ei ve dfed era l re s e a rc h nlo ne y viu t he Be gio na l He s e al'(;h Con lllJit te e o f t he I\'e s te r nS tu tcs for work on fund a me nt a l us pe c ts of s pri n k le r irri ga t ion . T his o p por tu-ni ty wa s util iz e d for s l ud yin g c crt a i n Iundu mcn tu l as pe cts o f irr igat ing byme ans o f mo vi ng s us pen ded pi pe . T he u s pc c t wh ic h is d is c us s e d here i sth at o f s u pp lyin g wa ter t o a mo v ing p ipe l ine .A l pr es en t 1\\ 0 s ys te ms o f s us pe nded, movi ng liTiga ti o n p ipe a rc in f ieldus c . In o ne , u lruu in um p ip e is mount c d a t in t erval s o n whe e ls, t he pipe bein ga t w he e l-a x le he ight or u ho ut :3 fe e t a bove th e gr o und s urfa ce . Thi s wh c e l-moun te rl p ip e, up 10 12 0 0 fe et in len g t h , c a n be move d pe rp e nd icular ly t o it slong axis by a t ra ct ive u n il a l t he m id d le o f t he l ine . AI pr es e n t , wa ter issu pp li e d b)' a l la c h ing t he p ipe l in e to d ifferent h)'dran ls b y hand or b)' " hang -ing th e positi on o f a pn mp s upp lyin g t he l ine . Th is s ys t em IS mu in lv us edfor pa sture irr ig a t ion .IUr. Bt':-; Std D. ",a ll 't \\'oud t is A s si st a nt Agric ult ural J<:ll gillt~ t' r u t th e Ha wu i i A gri cu l tu ral "::0;-p e r itue n t St atioll aud \ SSi s t il ll t l 'ro f t's s lIr or A gri c u ltura l 1' :ll girl( · t ~ r in g , Un ivers i t y of [ Iu w a i i ,In a no the r sys te m, pipe I S ca nt ile vered, up to 150 fe et , on each side ofa ce ntra I trac tor. T he can t ile ver ed s pri nk lc r mac hines a re us ed for irr iga t ingpi neapple on t he isla nds of ~'lo loka i a nd La na i a nd the y ha ve re ce nt ly be e nintr od uc ed in oth e r places t oo. On rela t ivel y f lat la nd, where grade c ontro l ispos s ible, th e tractor pumps wa ter from a diteh t hrough a f lat tened foot va lve .On ste eper land, where th e desired d itch grad e ca nnot be a tt a ined , water issupp l ied by coiling and unc o il ing ru bbe r t ub ing a ttac hed to a fix ed hydra nt.The huge c o i ls on th e ca nt i le ver ed machin es c ou ld be e l imina ted and a n op -port unity c ou ld a lso be cr eate d to s upply movin g wh e e l-mounted p ipe withwater, if it were possi ble to develop a pipe w ith a movin g d is charge ou tl et,as s uggested in figu re 1. A z ippe re d pipe, now us ed on a ircra ft ca rr ie rs forca ta pult ing plan es int o th e a ir (U. S. Navy, 1957) , has be en s ugge s te d forth is purpos e . Th is paper re po rts on the outc ome ofa mode l study of th is pos-s ibility .PHOCEDUHE AND HESULTSA Goodri ch zipper No . double 450 was mou nted , by vulcan izi ng , onto th etw o edges (al ong the long ax is ) of a s hee t of non -reinforc ed , extruded butylrub be r wi th mo lded s urface . Th e s hee t ha d a t hi cknes s of 3/ 16 in ch and wa s6 fe et lon g. On c los ing th e z ipper the s heet formed a t ube, 6 fee t lon g. Bothends of th is tubi ng were sea le d by pl a tes and , by add ing inte rna l sea ls, th ez ippe re d -pipe sec t ion could be s ubjec te d to hydr ostati c press ure . Th e te s tsc t-up a llo we d on ly 3 fe e t of head t o be appl ie d, a nd at thi s pre s sure thez ippe r proved wa te rt ight. T he man ufac ture r's da ta s ho w that t he z ippe r ha sa cross w ise s tre ng th of 225 p. s. i. (p ounds pe r sq ua re in ch) , a nd a le ng th-wis e s tre ng th of 25 0 p.a . i . As th e z ipper has be en design ed for a irt ight sca l-ing of a irc ra ft ca bi ne ts, an d c ons ider ing a lso th e prese nce of a rubber ov er -la ppi ng flap a t th e ins ide of t he z ippe r , it ca n be ass umed that th e z ippe r I Swa te rtight a t fi eld preSS llres norma lly encountered in irri gation pipe .This z ippe r ha s tw o s lide rs ; eac h s l ide r can be pl a ced in a ny posi tionwith respe ct t o th e oth er, s o th at a n ope ning of a ny s ize ca n be made a nypla ce a lo ng th e length of th e tubin g (fi gure O. By me ans of four wires, th etw o zi ppe rs are ope ne d or clos ed on moving th e di s ch arge outlet. Thes e wire sa re a ttac he d a t one e nd t o th e out le t a nd at th e other e nd to th e s lide rs ,(fi gur e s 2 a nd 3). Tw o wires a re a ttac he d t o eac h s l ide r ; one to th e uppers urface a nd one to the lower s urfa ce. As th e d isc ha rge out le t is mov ed alon gthe pip e, th e zipper o pe ns a head of it a nd clos es behind .4EndpluganchoredtogroundGasolineenginefortrailermovementDischargeaufletfromzipperedtubingAttachmentofoutlettotrailerfromtwosidestoprovidebalancedforceforslidingTrailerMovementPumpdischarge-tocantileveredorwheel-mountedpipeGasolineengineforpumpJetandbrushesforzippercleaning(2places)Steel-wirereinforcedzipperedtubingHydrantFIGURE1.Trailer-mountedpumpforwatersupplvfromzipperedpipetomovingcantileveredorwheel-mountedirrigationpipe.Notethatdischargeoutletofzipperedpipeisfixedtotrailerandthattubingmovespastitonmovingthetrailer.FIGURE2.Modelofzipperedpipe.Noteopeningforaccommodatingmovingdischargeoutletandmetalbarswithwiresconnectingoutlettoslidersonzipper.Thereisaslideroneachsideofthedischargeoutlet.ZipperSliderDischargeOutlet-----I-l----PressureGage(2places)Air-RegulatingValveFromeofDischcrgeOutletAirSpaceInflatedCylinder(2places)Zipper30'(8places)HousingforInflatedCylinder(2p laces)FlowDirection~"'ISteel-ReinforcedTubingWallWireforopeningandclosingzipper-------"'",FIGURE3.Crosssectionthroughdischargeoutletofzipperedpipe.Noteposrtronofinflatablecylindersandsliderattachmentatupperandlowersurfaceofzipper.Zipperisopenedatright-handsideandclosedatleft-handsideasthedischargeoutletmovestotheright,andviceversa.Th e di s charge outl et is thus located within a n ope n ing In th e tubin g,bUI within th is ope ni ng wa te r is dis ch arged thr ou gh th e o ut le t onl y . A s a tis -fa ctory fun ction in g of th e prin c ipl c of a movin g outlet is thus depend ent ona wa ters e al a t both th e upstream a nd th e d own stre am e nd of th e out le t . In th e6 -foo t - long mode l , a n a t te mpt wa s mad e to pr ovi de such a sea l by movin g th etubin g wall a s hor t distan c e a way from th e outlet betw e e n a n interi or, hol-low f iberg lass cy l inde r a nd a n exter ior, woode n cy l inde r. A lso , in a s epa ratecx perime nt (fi gure 4) , th e tubin g wall wa s moved betwe en a n e xter ior metalr ing with ball bea rin gs e mbe dde d a t its inte ri or pcri phcry a nd an o pposi te( int e ri or) metal cy l inde r. In both of these a tte mpt s , th e Forc e required tomove th e tubin g past th e sea l pr ov ed excess ive . On usin g a n e x ter io r a nd a ninteri or cy l inde r with ball bea rin gs opp osi te eac h other (and th e rubber mov-ing in betwe en) , no pr oper wa ter s e u l wa s o bta ine d e vc n though th e movin gfor cc wa s much s ma lle r .A more sa t is fac tory s o lution was found by insert ing a hollow, a lr- In-flat cd rubber c yl ind e r (Sca l Well , Wcstern Br a s s Works) within th e tubin g.By re gulating the ai r prc s surc w ithin t he cylind er , a good waters cal couldbe obta in cd while the c y li nde r mov ed up a nd d own th c tubin g by a pplyi ng afor ce of a pprox imate ly :3,5 pounds (figure 4) . As two cy l indcrs are requ ircd,onc on cac h side of th e di s ch arge outl et (fi gure :3 ) , th e total forc e to be ap-plied t o mov e a di s ch a rge outlct through a zi ppc rc d tubing would be a ppro x-ima te ly 70 pounds. The for ce re qu ired to ope n a nd cl os e th e z ipper is ne gli-g ib le.To pos sibly red ucc th is [o rcc , th e eoe ffic ic nt of fri ction wa s detcrmincdfo r rubber s l id ing ov c r (tr eated a nd un trea te d) rubbc r . Th e treat mc nts g ivc na nd th c rcs ults obta ine d arc sh ow n in ta bl e 1. It is no ted th at ru bbe r s l id ingovcr rub bcr s prayed with Tcflon s howe d the lea s t fri ct ion a nd th c lea s t var i-a b il ity in fri ct ion, whet her th e s urfaces we re dry or mo istc ne d . S il icon -s prayedrubbe r s howe d s l ig ht ly h igh er fr ict io n tha n T eflon- s pra yed ruhbe r ,Both the T efl on- and t he s il icon-s praye d surfaces produccd a fl e x iblefi lm , as was e v idenced in tests on th e inflatable cy li nder. T he for ma t io n ofthe fi 1m a ppe ar ed to be una ffec te d , whe n th e d ia me te r of t hc c y Iinder wasin crca s cd fr om :34 to 42 inc he s , I~i thc r of these spra ys cou ld th e re fore re'du c eth c movin g forcc of 70 poun ds if th c fil ms coul d stand up t o wea r und er fi eldcond it io ns .It is of intercs t to not e from tab le 1 th a t un trcated rubber s ho we d con-s idera blc va riat ion in the coe ffi cic nt of fr ic t ion in th c prcs en cc of wate r, Insomc cases moi s t s urfn c cs s howc d more fri cti on th a n dry surfaccs . Th is ap·peared to bc caus ed by vac uum pockc ts that de vc lop bc twc e n moist or wet,untrea ted rubber surfaces when they a re s lid ing over cac h ot he r. On s l id ing,thcsc pocke ts nc e d be climinatcd agai ns t atmos phcr ic prcs s urc.8~_.kF IG URE 4 . Mod el s tudies of wa t ers eal fo r i s ol atin g di s ch a r ge outl et from ma in b od y of z ip-pered tub in g.At le ft: Exterior ri ng wi th ba ll b eari ng s emb edded a t periphe ry of rin g, opposit e int eri o rmetal c yli n d er.A t cente r: Exterior a nd in te rior me tal r in g wi th ball beari ngs opposite each othe r.At righ t: Holl ow, in fl a t abl e cylind er us ed as seal .While th e inflated cy l inder led to a sa tis fac tory s ea l whe neve r pre s surewithin th e rubber tubing remain ed fix ed , a ny increa s e in pres sure w ith in th etubing ca used it to ex pa nd more than th e c y l ind er did, so that th e sea l a f-ford ed by the inflated cy l inde r be cam e ineffe cti ve. Therefore, e ithe r pre s surewi th in the tubin g must be c ontro ll cd , or mat eria l for th e tu bin g wa ll must bese lec te d that is flexibl e yet ex h ibi ts littl e variat ion in diameter w ith var ia-t ion in pres sure. T hi s can be ass ure d by the us e of ru bber re inf orced with,for instan ce , ny lon fiber s .9TABLE1.Coefficientoffriction,,u,ofbutylrubberslidingoverbutylrubberSurfaceSurfaceDry,Individualcondition,condition,moist,orMeasurementsAverageTreatmentSurface1Surface2wetof,uof).lmoldedmoldeddry1.00;0.90;0.850.922calenderedcalendereddry0.80;0.70;0.70;0.670.60;0.60;0.603cellophanecellophanedry0.64;0.65;0.35;0.49curecure0.35;0.47.\cellophanecellophanewet0.70;0.70;0.65;0.73:::>curecure0.72;0.875cellophanecellop hanemoist3.99;2.00;0.75;1.42curecure2.40;1.25;0.81;0.75;1.70;1.20;0.90;0.75;0.62;0 .85;1.25;2.006cellophanecellophanedry0.50;0.50;0.500.50curecure,treatedwithsiliconspraycellophanecellophanewet0.40;0.40;0.400.40curecure,treatedwithsiliconspray(Conihilled)TABLEL(Continued)SurfaceSurfaceDry,Individualcondition,condition,moist,orMeasurementsAverageTreatmentSurfaceISurface2wetofjJ.ofjJ.8moldedmolded,treateddry0.60;0.60;0.600.60withsiliconspray9moldedmolded,treatedwet0 .30;0.30;0.30;0.31withsilicon0.35spray10moldedmolded,treatedmoist0.60;0.80;0.50;0.51withsilicon0.47;0.40;0.40;spray0.4011cellophaneTeflonwetor0.20;0.25;0.25;0 .27curedry0.30;0.30;0.30;0.20;0.35;0.35;0.2212moldedTeflonwetor0.20;0.30;0.25;0.24dry0.23CONC LUSIONST he concl us io ns dr a wn from t he model s tud y a rc :( I) A di s ch a rge out le t ca n be moved w it h in a z ippe re d t ub ing wit hreas ona ble for ce .(2) T he s iz e of the dis c harge out let ca n be va rie d a t w il l.(:3 ) A z ippe rc d t ub ing is probab ly le ak proof a t d is ta nces fro m th e out-le t , a t field pre s s ures .(/0 T he Goodr ic h z ippe r t ested is s u ita b le, in a ge nera l way, but fort he devel opm en t of a f ie ld model req uire s s mooth ing of the inn ers ur face .(5) T he di s ch a rge outle t ca n be ma de leak proof by insert ing two, in-fla ted holl ow cy linde rs, one on each side of t he outlet.(6 ) Hei nforced tu b ing , or equiva le nt mate ri al , must be s elected w it hsuff ic ie nt crosswise a nd len gth w is e strength, so tha t tbe t ub ings ho ws ne gli gib le vari ati on in d ia me te r wit h var iat ion in pre s s urewi t hin a g ive n ra nge and ca n wit hstand th e force req uired t o mov eth e tubin g pas t th e d is c harge out le t.HEFEH EN CEll n it ed St a tes Na vy . 1957 . T he s te a m ca ta pu lt- it s hi story an d opera t io n.NA VA I~H 00-80 '1'-69.UNIVERSITY OF HAWAIICOLLEGE OF TROPICA L AGRICULTUREHAWAII AGRICULTURAL EXPERIMENT STATIONHONOLULU, HAWAIITHOMAS H. HAMILTONPres ident of th e Unive rsityDALE N. GOODELLActing Dean of the College andActing Director of th e Experiment StationGEORGE STAN FORDActing Associate Director of th e Experiment Station

Zippered-pipe principle for irrigation water supply

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Zippered-pipe principle for irrigation water supply

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