Oct 01, 20 ron astall, united pumps australia ask ten different pump engineers for their guidelines on establishing centrifugal pump minimum flow and you might get ten different answers. Call or email us any time, any day to contact an experienced goulds pump expert for sales, service, and support. Lf 3196 iframe goulds pumps pdf catalogue technical goulds 3196 iframe process pump. Cable selection select a drop cable designed for use in water. The operating point of a centrifugal pump, also called its duty point, is given by the intersection of the pump characteristic curve with the system curve. These lines intersect with the headcapacity curves and are typically labeled with percentages. Each graph will usually have curves representing the pump head vs. The head difference between the two curves is the pressure drop across. Use the line tab to adjust pump speed and impeller diameters and to graph pumps individually, in series or in parallel. Discreetly applied either below or above the pump performance and efficiency curves, this single plotted line is the key to avoiding cavitation. Qh curves will be given by the manufac turer of the. Offered in carbon steel, ductile iron, 316ss, cd4mcu, alloy 20 and hastelloy c, the ht 3196 iframe provides a wellrounded selection of materials to maximize pump life when pumping hot. Jan 08, 20 a pump will operate where its performance curve intersects the system resistance curve above centre as shown by the dotted lines. Goulds model 3196 chemical process pumps designed for total range of industry services capacities to 7000 gpm 64 m3h heads to 730 feet 223 m temperatures to 700f 371 c pressures to 375 psig 2586 kpa outstanding features.
For systems pump manufacturers normally publish a set of with a high total head this. Reading and understanding centrifugal pump curves is key to proper pump selection, and to their reliable and efficient operation. Water circulation booster service liquid transfer spray system chillers washingcleaning systems injection molding cooling reverse osmosis air scrubbers heat exchangers filtration systems jockey pumps oem applications general water services features and benefits high efficiency impeller. In centrifugal pumps the delivery head h depends on the flow rate q. Used durco horizontal singlestage centrifugal pump. Contact a customer service rep for additional resources. If a pump is offered with multiple impellers with different diam eters, manufacturers typically plot a separate pump curve for each size of impellor on the same pump performance chart. Judging by the questions i see asked nearly every week on linkedin and elsewhere, i believe this is a problem shared by many engineers early in. The pump curves start at a high point on the left side of the graph called the shut off head. Itt industries goulds pumps pump selection system pss user s guide 12 line displays the singleline and viscous performance curves. A definition that at first glance seems more than reasonable is as follows. Taco radiant made easy application guide technical documents. This literature library allows you to browse goulds water technologies extensive archive of technical documents, brochures, warranties, bulletins, guides, and other useful product literature by document type.
To do that, an engineer would refer to a pumps composite curve. The performance curves for a centrifugal pump are shown in figure 1. A comparative study on centrifugal pump designs and two. We consult pump curves not only to see if they can do the work we need them to do but if they will do it efficiently. This short article takes an indepth look at pump curves. From there you can adjust operating speeds, viewsave electronic curves and data sheet reports in a pdf format, generate. Pump selection download the pss user guide to learn how to view individual performance curves when only pump model and size are known. The lowest pump flow that can be maintained continuously. Understanding centrifugal pump curve chemical engineering site.
The actual flow increase above 50% cannot be determined until the full analysis is completed. Unlike positive displacement pumps such as piston pumps, centrifugal pumps deliver a var iable flow rate q increasing. Even agreeing on a basic definition for minimum flow can be problematic. From there you can adjust operating speeds, viewsave electronic curves and data sheet reports in a pdf. Each product page has tabs to give you quick acces to the literature brochures, ioms, technical guidelines, parts lists submittals, curves and drawings for that product. Centrifugal pump curves estimate pump performance at different impellor diameter and speed based on affinity laws. Basic paralleled pump operating point figure 2 figure 1 shows that each pump in a two pump parallel system with identical pumps is pumping onehalf of the total design flow rate. Pump efficiency and power pump efficiency, epump pump water horsepower whp e brake horsepower bhp 221 n by the pump manufacturer calculate required bhp, knowing epump water horsepower is defined as. The h in the curve is the difference in energy level between the suction and the pressure side of the pump. The goulds ht 3196 iframe features superior chemical corrosion resistance through optimal manufacturability of high alloy wetted pump components. Reading centrifugal pump curves national environmental.
Centrifugal pump performance curves and technical information. The insulation on the conductors should be rw, ruw, tw, or their equivalent. To change the operating point either the system curve or the pump curve must be changed. Jordan, an application engineer at crane engineering, explains how to read a centrifugal pump curve in the video below. These curves show the performance of the 3656 and 3756 at 3500 rpm and 1750 rpm, 60 hz, and at 2900 rpm and 1450 rpm, 50 hz. Reading pump curves by james mcdonald, pe, cwt originally published. All pump manufacturers have paper curves representing the performance of their pumps, and most also have these curves available in pdf format. If i have over headed the pump by only 20%, i will be at the failsafe point of operation where pump damage may occur. This volume is measured over a period of time expressed in gallons per minute gpm or gallons per hour gph. These four curves velocity head relate head, efficiency, power, and net positive sucvelocity head is the amount of energy required tion head required to pump capacity figure 3.
Cds displays the primary and water equivalent performance curves. Goulds model 3996 inline process pumps goulds pumps pdf. Actual on site performance will be given by the intersection of the pump curve with the actual system curve. The performance of a centrifugal pump is shown by a set of performance curves. Head, power consumption, efficiency and npsh are shown as a function of the flow. With this in mind, the curves typically plotted are head vs. Fortunately, manufacturers include this information on the curves as well. Using the selection chart to narrow down the appropriate pumps size for the duty point of 1,000 gpm and 100 feet of head, the manufacturers published curves can be referenced to help determine the best pump for an application. The red dot represents the minimum speed the pump may run at full flow rate before operating off the end of the curve.
Pump performance curves pump performance curves are generated by conducting water tests on pump and impeller. The dynamic seal which, simply by fitting a repeller between the stuffing box cover and impeller, eliminates the need for a mechanical seal. View controls which curve elements system curves, etc. This tech brief examines how pump curves can provide data about a pumps abili. Reading and understanding centrifugal pump curves is key to proper pump selection, and to their reliable. Npenpef 316l stainless steel pumps xylem applied water. The characteristic curves of centrifugal pumps plot the course of the following parameters against flow rate q. Get access to national pump s product brochures, manuals, and prodct catalog on our resources page. Pump curves for hydronic circulators always show the head energy added along the vertical axis and the flow rate through the circulator on the horizontal axis. The corresponding theoretical head coefficient curves are presented in figure 12. Jun 26, 2014 knowing how to read a centrifugal pump curve is essential to the health of your system. This tech brief examines how pump curves can provide data about a pumps ability to produce flow against certain head, shows how to read a typical centrifugal pump curve, and provides. Pump category subcategory distillation hydrotreating hydrocracking catalytic cracking residuum and heavy oil upgrading gas treating and sulfur recovery lng ngl and lpg gas to liquids offsites and waste treatment heavy oil, oil sands and shale crude, product and co. Reading and understanding centrifugal pump curves is key to proper pump selection, and.
Cstn septemberoctober 2004 t he performance of a centrifugal pump can be shown graphically on a characteristic curve. Choose from over 6,000 sizes in goulds extensive offering. This relationship, also called pump performance, is illustrated by curves. Pump iso efficiency and other curves every pump manufacturer generates pump curves for every type of pump to define. You will talk to a live person who knows goulds water technology. Back to basics w hen i left university, i found that i needed additional information to turn my theoretical knowledge of fluid mechanics into the practical knowledge required to specify a pump. A typical composite curve includes the pump performance curves, horsepower curves and npsh required. Paying a little more will save you money in the long run. Let us look again at examples of stable and unstable pump curves. This volume is also referred to as capacity or flow. Introduction to pump curves the pump develops energy called discharge pressure. Pump performance charts with multiple pump curves are shown below. The graphs will also show curves of constant efficiency and constant pump power bhp.
May 04, 2018 the blue dot in the curves above is the design point. Viewing and printing pump performance curves curves screen the curves screen allows you to analyze, compare and print the selected performance curves. The characteristic curve s shape is primarily determined by the pump type i. Actual pump performance data will typically be presented graphically as shown in fig. One of the most important lines on a pump performance curve is the net positive suction head npsh curve. During a bench test, the pump is operated at constant speed and the values q and h are. Running too far out on the curve, or too far back, can cause damage to the pump, excessive energy consumption, and overall poor performance. Pump selection download the pss user guide to learn how to view individual performance curves when only pump model and size are known customized pump selection and analysis. A typical characteristic curve shows the total dynamic head, constant horsepower, efficiency, and net positive suction head all. Smaller impellors produce less pressure at lower flow rates.
Goulds pumps and rheinhutte pumpen presents this centrifugal pump selection guide to assist users in making an easy initial selection of the best pump for a particular service. However, in order for a software program to understand and use this pump performance data, these curves must first be converted into a form which can be read by a software program. How to read a centrifugal pump curve crane engineering. Complete pump performance data and product information.
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