Document k6DQRdp9nVDakVKnENOqBJrD

6Vortloat-haft 1000-gpm turbine daopwelt pump operating under 29S-ft total head, and driven at 1760 rpm through an angle gear by 100-hp dleael engine STANDARD MATERIALS IN VERTICAL TURBINE PUMPS PsrU Bowl* Iraptllan Wnrlnf tl*|i Bowl baartan Pampahaft Bowl Assembly Usutlsf Cti Iren Broan or cut Iren Bronte Bfeoii or rabbit Suinlou ttttl Cilatae pipe LTnnbift and couplEnti 6hi(t-indeila| tuba Bntloilnf-tube itabillnr Opm-Hna ahalt*baarlot tatalnar Bnctend lloithaEi bnrlo(i Opaa llaethift beorlns* Opao llnaibift alnva Cottnna Assembly 8tl Still Stiil Rubbu er broon Brenie Drenn Rabbit Monil or lulnlin itnl Hetil Assembly Dlicturfi bud Btuffia* be* 8tiAn|*bi (land Top ihaft: enclo*cd-*hft eomttuelieo Top ihilt: eptn-thi(t conttfuctioa Cut Iroa . Cut Iren Broon et cut Iroa Btiol Btiiolm itnl or ttnl with itaffln|<be> )** shafts usually come in 10-lt length connected by couplings, threaded so they cannot uncouple while pumping. With open-ahaft construction, rig. I. bearing retainera R support the bear ings usually located ot the end of each column-pipe section. Thus, if pipe lengths are 10 ft long, shaft-bearing spacing becomes 10 ft. With enclosedshaft construction. Fig. 2, the shaft is enclosed in a tube, usually half the shaft's length and connected by hronte bearing! threaded to serve os tube couplings. For example, if shafts are 10 ll long, bearings are spaced 5 (,11 apoart. $1 Q IS--JPhaS determine* shaft column <(t7 jl A--Power requirements aod ihruy'] loads determine shaft sizes. Maxlmua)| allowable eombioed shear stress is (SOoojJ pel, and maximum allowable combined u tensile stress is 9000 psl as usually ap. ll plied. Friction-head loss determine) * column-pipe alze. Increasing colunu i pipe site reduces friction-head loss. ^1 While this saves power, first coit b jl increased. "H Q 14--tPkai I* the pump's driving. J heed oiMmMyP A--This Is the portion of a vertical.' turbine pump located above foundation' level. When discharge is above ground, a discharge head containing a dUchargt elbow is included. This unit supports the pump driver and provides a bate from which column and bowl assea-! blies ore suspended. When discharge is underground s. simple motor support, similar to a spool piece, substitutes for the discharge' I head just described, and a discharge tee is placed in the column pipeline at the required location. Q lS--~Does type of shaft construc tion offset design of head assembly? A--Yes, open-shaft construction re quires a stuffing box and packing around the revolving shaft, whereat with an enclosed shaft, a stuffing boi is not needed. Tbe shaft-enclosing tube keeps water- from the shaft snd since there is no rotation, a simple gasketed joint !{ used where the tube pastes through tbe head assembly. Bottom end of tbe thaft-enoiosing tube is vented to the well at T, Fig. 2, immediately belo* where it connects to the pump's dis- charge ease or bowl. This vent prevents ! Mgh-prcssure water entering the shaft! j tube; consequently no pressure exists j where the rotating shaft passes through the head assembly. j Various methods are used to admit .! lubricant to the enclosing tube, some of . these use single- or double-ring packing ! to prevent lubricant overflow where it ! enters the tube. Such a stuffing bos, ] however, does not come fn contact with ; the pumped liquid. , Q 16--Does shaft construction affect bowl-assembly design? A--Yes, with open-shaft construction the discharge connection is threaded or flanged for connecting to the bowl and column assemblies. When an enclosed shaft is used, the top bowl or discharge (Continued on page 146) 101 (4)) POWER January' 1941.