Bulletin - Peerless Pump

Figure 1. HORIZONTAL closecoupled end suction.Figure 2.HORIZONTAL double suction split case.Figure 3.VERTICAL turbine pumpGPMHead,Ft.MotorHpMotorSpeedFig. 1. H O R IZO N TA LEN D SU CTIO NFig. 2.H O R IZO N TA LDOUBLE SUCTIONFig. 3.VER TICA L TU R B IN E Area RatioHeight RatioL W A1 H1 L W A2 H2 L W A3 H3 A/A3A2/A3H3/H H3/H2100 130 5 3460 25.50 11.00 281 8.75 41.50 16.50 685 17.88 12.5 12.5 156 27.38 1.8 4.4 3.1 1.5150 250 15 3460 31.38 15.88 497 8.69 46.12 20.00 922 19.00 19.0 19.0 361 36.19 1.4 2.6 4.2 1.9300 200 20 3460 35.50 15.88 564 12.88 51.44 21.00 1080 21.00 19.0 19.0 361 42.44 1.6 3.0 3.3 2.0500 160 25 3460 36.75 16.50 606 13.88 51.44 21.00 1080 21.00 21.0 21.0 441 42.44 1.4 2.5 3.1 2.01000 160 50 1760 67.12 29.00 1945 28.50 21.0 21.0 441 50.62 4.4 1.81500 160 75 1760 67.12 29.00 1945 31.00 23.0 23.0 529 57.75 3.7 1.92000 160 100 1760 81.25 35.25 2860 33.33 31.0 31.0 961 65.75 3.0 2.02500 190 150 1760 81.25 35.25 2860 34.88 31.0 31.0 961 72.50 3.0 2.13000 210 200 1760 98.50 43.50 4280 38.62 31.0 31.0 961 72.50 4.5 1.93500 225 250 1760 97.00 44.00 4275 43.00 38.0 38.0 1444 77.25 3.0 1.8N O TE: L, W , & H are expressed in inches. H = O v e r-a ll H e ig h t.TIB#2Horizontalvs.VerticalPum psA=Total F loor A rea of B ase Expressed in square inches.lift or submergence is fixed by the plant layout.Consequently where extremely low NPSH is availablethe vertical pump is usually far easier to adapt than ahorizontal.A good example of this occurs frequently in theapplication of condensate pumps. Hot wells areoften located close to the floor in order to reducethe over-all height and thus the cost of the building.However, by so doing, the NPSH availablewith respect to the floor is minimized. Thus it is notuncommon on condensate pump applications tohave only 2 or 3 feet NPSH available withrespect to the floor. It can be seen from Figure 4that by using a vertical pump enough submergence can beadded to the 2 or 3 feet to insure cavitation-free operation.Figure 4. Application of vertical pump in condensate hot wellTIB# 2 Page 2

column to which it is attached. In contrastto this, for example, is the doublesuction, horizontally split, horizontalpump. Figure 7 pictures such a pump.with the upper half of the caseremoved thus allowing the completerotating unit to be visually inspectedand removed if necessary. Neither thepiping nor the motor need bedisturbed to remove the rotatingelement There are also verticallysplit horizontal pumps designed sothat it is unnecessary to disturb themotor or piping in order to remove therotating assembly.Horizontalvs.VerticalPum psConclusions-Besides the characteristicsof the pump itself, there arecertainly other factors which influencethe choice of pumping equipment, notthe least of which is the designandconfiguration of the plantequipment and layout, with which thepump must be coordinated. Otherfactors such as safety regulations willaffect the choice of pumpingequipment. For example, in order toavoid side outlets in the storagetank it is normally good safety practiceon above ground tanks to use verticalwet pit pumps when pumping oleum.But even where well defined factorssuch as these do not pre-determine thechoice of pump types, it is a mistake tomake any hard and fast rules about theselection of a horizontal over a verticalor vice versa. Often in marginal cases,where new equipment is beingconsidered, it would be expedient toobtain quotations on both horizontaland vertical types. Each applicationmust be judged on its own merits,keeping in mind the basic advantagesand disadvantages of each type, asoutlined above.View ofdouble-suction,horizontalysplit,horizontalpumpFIGURE 7View showing com plete rotating elem entTIB#2 Revised 10-7-02 Page 4