Examples of these pumps are shown in figure 2 figure 2 gear pump and screw pump most pipelines transporting water and petroleum products today use centrifugal. Thedimensionalmatrixrevealsthat for6dimensionalvariablesonly3dimensions mass, length,andtimeexist. Operating characteristic curves of a centrifugal pump. Grundfos product center makes accessing and reading pump curves easier than ever. The choice of pump for a given application depends largely on how the pump headflow characteristics match the requirement of the system downstream of the pump.
Centrifugal pump curves show 8 important factors that are critical in selecting the right pump for your application. The characteristic curves shape is primarily determined by the pump type i. Pump headflow curves are typically given for clear water. May 03, 2018 it is made up of four to five points, each point being obtained from a separate npsh test at a different constant flow. The efficiency of centrifugal pumps varies over the individual curve. Centrifugal pump pump curves pumps can generate high volume flow rates when pumping against low pressure or low volume flow rates when pumping against high pressure. Dec 11, 2015 jordan walks us through a standard centrifugal pump curve and describes what the different sections mean. The difference lies on one hand in the principle of transporting the liquid and on the other hand in the pumping characteristic. Secondary objectives are to familiarize the student with the characteristics of a centrifugal pump and to introduce the student to the homologous scaling relationships. Centrifugal pump selection software in water pipeline systems. Head is a measurement of the height of the incompressible fluid column the pump could create from the kinetic energy, that the pump gives to the liquid. Then,maximally3independentdimensionlessvariablesmaybeobtained. The h tq curve shows the relationship between head and flow rate.
To find out the operating points for each centrifugal pump model included in your current analysis. The fastest way to access pump efficiency curves and other pump information. This is normally carried out after the abovementioned tests. To change the operating point either the system curve or the pump curve must be changed. When sizing, it is helpful to select a pump whose curve puts the duty point as close to this bend in the curve as possible.
Impeller size within a given housing, the impeller diameter will determine. To find out which the total pump flow and head are in your pumping pipeline system. The rotodynamic pump, usually a centrifugal pump has a curve where the head falls gradually with increasing flow, but for a pd pump, the flow is almost constant whatever the head. Centrifugal pump classification number of stages single stage multistage shaft position horizontal vertical horiz. Deviation of suggested method from experimental data were considered and discussed. Experimental study of characteristic curves of centrifugal pumps working as turbines in di. According to calculation or the use of tables which is not presented here the friction loss for a 1 tube is has a friction loss of 0. Drive and pump shall be designed for continuous or intermittent service.
There are several terms associated with the pump characteristic curve that must be defined. Pdf dimensionless characteristics of centrifugal pump. Two equations were presented to estimate the complete characteristic curves of centrifugal pumps as turbines based on their best efficiency point. Information is plotted on an xy graph where the xaxis is measured in units of flow and the yaxis is measured in units of head, power, and npshr. Finally, a procedure was presented for selecting a suitable pump to work as a turbine in a small hydrosite.
A typical composite curve includes the pump performance curves, horsepower curves and npsh required. In addition, this experiment gives the student further exposure to the use of. Running too far out on the curve, or too far back, can cause damage to the pump, excessive energy consumption, and overall poor performance. Centrifugal pump characteristic curve components of. Depending on the required delivery head, the centrifugal pump will find its operating point when the plant curve and pump curve meet.
In a rotodynamic pump, a rotating impeller imparts energy to the fluid. How to select a centrifugal pump examples of total head calculations sizing a pump for a home owner application 14. Horizontal end suction centrifugal pumps per awwa e10315, the pumps shall have a continuously rising characteristic curve from rated points to shutoff. Shutoff head is the maximum head that can be developed by a centrifugal pump operating at a set speed. Pdf in the world of hydraulics, the most preferred pumping devices are centrifugal pumps. Centrifugal pump characteristic curve for an operations engineer who is working in a chemical process industry or a process engineer who is involved in hydraulic calculations understanding the centrifugal pump performance curve is an important aspect. To do that, an engineer would refer to a pumps composite curve. Lesson 28 characteristic curves of centrifugal pumps. The pump curve also displays the pump model, the pump size and number of stages for multistage pumps. Dimensionless characteristics of centrifugal pump tointerchangecolumnn bycolumn inthedimensionalmatrix 3. Centrifugal pump characteristic curve engineers edge. The results tab will show the required info that will allow you.
When displaying pump curves in pipeflo or pump flo, the amount of information displayed on the curve. Being able to read a pump curve is critical when trying to diagnose a pump problem. Rotary pumps include gear pumps and screw pumps used with high viscosity liquids. Components of centrifugal pump performance curve 1. What is total head 10 what is the relationship between head and total head 11. Whats the significance of pump characteristic curves. Pdf characteristics of centrifugal pumps working in direct. Pdf experimental analysis of performance of centrifugal pump. Typical selection criteria for centrifugal pumps are their design data flow rate or capac ity q, discharge head h, speed of rotation n and npsh, the properties of the fluid pumped, the application, the place of installation and the applicable regulations, specifications, laws and codes.
The characteristic curves of centrifugal pumps plot the course of the following parameters against flow rate q. Positive displacement pumps are those in which energy is imparted to the liquid in a fixed displacement volume, such as a casing or a cylinder, by the rotary motion of gears, screws, or vanes, or by reciprocating pistons or plungers. A typical centrifugal pump characteristic curve is shown below. Pump runout is the maximum flow that can be developed by a centrifugal pump without. Jun 23, 2016 lets first go through the characteristic curves of centrifugal and reciprocating pump so that the ones referring it for the first time also get the idea of it.
Reading and understanding centrifugal pump curves is key to proper pump selection, and to their reliable and efficient operation. The characteristic curve shows the mechanical power input p 2. Characteristic curves for a centrifugal pump examining figure 3, the general performance of the pump can be determined. It is customary to draw the curve for pd pumps with the axes reversed see section 4, but to. Centrifugal pump curves formats engineered software. A pump curve provides a wealth of information regarding the performance capabilities of a pump. In a centrifugal pump characteristic curve, efficiency curve starts from zero at zero flow and goes like a trajectory having a best efficiency point and then the efficiency starts falling for increased flow rates. The flow rate q and the developed head h are both determined by the intersection. Understanding centrifugal pump curve chemical engineering site.
Jun 26, 2014 knowing how to read a centrifugal pump curve is essential to the health of your system. Pdf laboratory report centrifugal pump anh phuong le. This type of curve is referred to as a rising characteristic curve. The h in the curve is the difference in energy level between the suction and the pressure side of the pump. Are you looking for a way to quickly verify that the pump youve chosen can meet your duty points. Centrifugal pump performance curves and technical information. For the sake of example, today were going to look at a selection made for the following design. How to read a pump curve for centrifugal pumps pumpworks. The most common type of rotodynamic pump is the centrifugal pump figure 1. Usually the operating point is not on the qh curve of the pump. Now consider a centrifugal pump is required to pump water from one vessel to another vessel, the pump parameters. The first step on the way to the optimal pump is the selection between a centrifugal pump or a positive displacement pump.
Casing design radial axial radial axial stage casing. How to read a centrifugal pump curve crane engineering. The headdischarge curve hq curve relates the head produced by a pump to the volume of water pumped per unit time i. Qh curves will be given by the manufacturer of the pump and can normally be considered as a simple quadratic curve. However, keep in mind that proper consideration of pump design considers not just the pump but the. A typical head flow curve for a pump is shown in figure 7. 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. Characteristic curve pumps, valves and service ksb. Understanding centrifugal pump curves when selecting a centrifugal pump, one should match the performance of the pump to that needed by the system. Experimental study of characteristic curves of centrifugal. Module 60 centrifugal pump selection part two proudly sponsored by this skills workshop is part two of a twopart series covering how to select the correct centrifugal pump for a particular design and application.
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. In fluids dynamics the term pump head is used to measure the kinetic energy which a pump creates. Centrifugal pump exercise b objective to create head, power and efficiency characteristic curves for a centrifugal pump. Switch on the fm50 pump within the software using the pump on button. The most efficient point of two curves is illustrated in figure 1. How to read a centrifugal pump performance curve mechanical. Best efficiency point bep is the point on a pump performance curve corresponding to the flow rate with the. The possible combinations of total pressure and volume flow rate for a specific pump can be plotted to create a pump curve. Theory one way of illustrating pump characteristics is to construct contour lines of. Pumps shall be capable of operating at any point on the headcapacity curve without exceeding the motor nameplate rating. Centrifugal pump selection and application into the system foreword this article is a note or manual for mechanical engineer where work as rotating engineer or where concern to apply centrifugal pump into the system.
1323 1056 1642 1008 1543 1357 1432 856 983 495 1457 917 895 834 391 1478 550 662 183 323 1182 231 490 1273 685 347 284 928 42 1508 278 142 1305 453 472 1621 194 1317 651 757 1290 824 142 1111 449