Pump terminology handbook

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Already a member? Close this window and log in. Join Us Close. Are you an Engineering professional? Join Eng-Tips Forums! Join Us! By joining you are opting in to receive e-mail. Promoting, selling, recruiting, coursework and thesis posting is forbidden. Students Click Here. Related Projects. We are five fourth-year translation students who have been asked to translate a handbook about pumps from Spanish to English, and we have reached a high level of desperation by now, because none of us had the slightest idea of how these machines work.

Pumps, what a world!!! You would really help us if you could answer some of the doubts that we have come across during our translation process. We are having serious problems with some terms and also in understanding some parts of the text.

Which is not very well written in Spanish, we must say So, without further ado, here are our doubts and questions: First of all, we would like to ask you if you could just please provide us with some websites, online glossaries, a handbook of pumps or anything else that could help us in our translations. Secondly, we have some doubts about terminology that hopefully you could solve. There's a moment were it talks about the efficiency rate of the machine.

In our text in Spanish, it says that the energetic efficiency is "0. When referring to gear pumps or any other kind for that matter I have a sentence in Spanish which would translate literally as 'Manometric load' Do we use the term manometric to talk about pump pressure?

The passage I have refers to external gear pumps as being lobe pumps. My question is: are all external gear pumps lobe pumps or are lobe pumps one type of external gear pump? In the Spanish version, we found the term "cortadura", which means the action that the pump makes over the fluid continuity.

Some pumps may create a greater interference over that liquid smooth flow than others. We are not sure whether the correct term to define the action of the machine over that fluid continuity is called "cutting". Could you help us? We understood that inert gas pumping systems work in a four-phase cycle: could you tell us what is the name of these four phases?

We have the names in Spanish and we can't find an English equivalent. Thanks in advance for your help. It would possibly help, if you provided the Spanish text of the phrases you want to translate. I would think "pressure load" might be what you are looking for. Force and pressure is basically represent the same scaler quantity anyway, when taken over a unit area. Good luck. Be careful of on-line translators, they suck to say the least.

Particularly on technical terms. You'll be better off to check with a bilingual engineer. From personal experience, it is far better if that person's native tongue is the same as the one your translating from but has been working in the language it is translated to. And as BigInch says, it'll be easier if you put the spanish text, some of us might have a crack at it. I'd say the reverse, from Spanish to English works best with an English engineer knowing Spanish.

That I say from experience, this year having translated the Spanish solar photovoltaic design and installation guide, the local utility grid tie-in specs, as well as a number of the more important legislative acts setting the grid sale rate for various renewable energy power systems from SP to EN.

The online translators are useless total crap. To give you an example, They always translate "fine", as in "how are you feeling" to "multa", "Pay the fine. They also have virutally no techncial terms in the technical context in their dictionaries. In fact, a translation to pressure head ight be what you're looking for above, but withou the orig txt, I don't know. BTW, cast e llano from Castilla is the name given to the official language of the Hispano American countries.

That's a good idea! What do they say for cortadura? Please tell me that's a Google translation of an english text. Ok, should be carcaZa, grammar is pretty poor and uses very funny words, not incorrect ones, but not commonly used. Is the book translated in Spain by any chance?

Hi guys. It's funny to see how this thread has become a discussion about translation. They are used extensively in the state of Florida to control the water level in the canals of low lying farming areas.

The water is pumped over low earthen walls called burms into the South Florida Water Management Disctrict main collecting canals. Barometric pressure : the same as atmospheric pressure , the pressure in the local environment. Barometric pressure is a term used in meteorology and is often expressed in inches of Mercury. Baseplate : all pumps require some sort of steel base that holds the pump and motor and is anchored to a concrete base.

Best Efficiency Point B. At this point, the impeller is subjected to minimum radial force promoting a smooth operation with low vibration and noise. When selecting a centrifugal pump it is important that the design operating point lie within the desirable selection area shown in the next figure.

Bingham plastic : A fluid that behaves in a Newtonian fashion i. For more information see non-newtonian fluids. Bourdon pressure gauge : the Bourdon tube is a sealed tube that deflects in response to applied pressure and is the most common type of pressure sensing mechanism.

Bowl vertical turbine pump : the casing of one stage a multi-stage vertical turbine pump. To find out more about control systems, this is an excellent treatment by www.

Thanks to Walter Driedger of Colt Engineering a consulting engineering firm for the petro-chemical industry in Alberta, Canada. Calculation software : doing pump system calculations and pump selection can be a long manual process with opportunities for many errors. This sofware can resolve complicated systems with multiple branches, handle control valves and other equipment and help you do the final pump selection with the manufacturer's electronic pump performance curves providing you with customizable search features to obtain the optimum selection.

Capacity : refers to a pump's flow rate capacity. Casing : The body of the pump, which encloses the impeller, syn. Cavitation : the collapse of bubbles that are formed in the eye of the impeller due to low pressure. The implosion of the bubbles on the inside of the vanes creates pitting and erosion that damages the impeller. The design of the pump, the pressure and temperature of the liquid that enters the pump suction determines whether the fluid will cavitate or not.

These bubbles will be rapidly compressed by the pressure created by the fast moving impeller vane. The compression creates the characteristic noise of cavitation. Along with the noise, the shock of the imploding bubbles on the surface of the vane produces a gradual erosion and pitting which damages the impeller.

Cavitation damage on an impeller of a Robot BW pump image provided by my pump friend Bart Duijvelaar. Centrifugal force : A force associated with a rotating body. In the case of a pump, the rotating impeller pushes fluid on the back of the impeller blade, imparting circular and radial motion. A body that moves in a circular path has a centrifugal force associated with it.

Try this experiment, find a plastic cup or other container that you can poke a small pinhole in the bottom. Fill it with water and attach a string to it, and now you guessed it, start spinning it. The faster you spin, the more water comes out the small hole, you have pressurized the water contained in the cup using centrifugal force, just like a pump.

Check valve : a device for preventing flow in the reverse direction. The pump should not be allowed to turn in the reverse direction as damage and spillage may occur. Check valves are not used in certain applications where the fluid contains solids such as pulp suspensions or slurries as the check valve tends to jam. A check valve with a rapid closing feature is also used as a preventative for water hammer.

Colebrook equation : an equation for calculating the friction factor f of fluid flow in a pipe for Newtonian fluids of any viscosity.

This factor is then used to calculate the friction loss for a straight length of pipe. To understand how to solve the Colebrook equation for the friction factor f using the Newton-Raphson iteration technique, dowload this pdf file. Here is an interesting article on alternate explicit and very precise version of the Colebrook equation. Chopper pump : a pump with a serrated impeller edge which can cut large solids and prevent clogging.

Closed or open impeller : the impeller vanes are sandwiched within a shroud which keeps the fluid in contact with the impeller vanes at all times. This type of impeller is more efficient than an open type impeller. The disadvantage is that the fluid passages are narrower and could get plugged if the fluid contains impurities or solids.

In the case of an open impeller, the impeller vanes are open and the edges are not constrained by a shroud. This type of impeller is less efficient than a closed type impeller.

The disadvantage is mainly the loss of efficiency as compared to the closed type of impeller and the advantage is the increased clearance available which will help any impurities or solids get through the pump and prevent plugging. You can view the Sims company. CV coefficient : a coefficient developed by control valve manufacturers that provides an indication of how much flow the valve can handle for a 1 psi pressure drop. For example, a control valve that has a CV of will be able to pass gpm with a pressure drop of 1 psi.

CV coefficients are sometimes used for other devices such as check valves. Cutwater: the narrow space between the impeller and the casing in the discharge area of the casing. To reduce pulsations in critical process', more vanes are added. Darcy-Weisbach equation : an equation used for calculating the friction head loss for fluids in pipes, the friction factor f must be known and can be calculated by the Colebrook, the Swamee-Jain equations or the Moody diagram.

Dead head : a situation that occurs when the pump's discharge is closed either due to a blockage in the line or an inadvertently closed valve. At this point, the pump will go to it's maximum shut-off head, the fluid will be recirculated within the pump resulting in overheating and possible damage. Diffuser: located in the discharge area of the pump, the diffuser is a set of fixed vanes often an integral part of the casing that reduces turbulence by promoting a more gradual reduction in velocity.

Diaphragm pump : a positive displacement pump. Double Diaphragm pumps offer smooth flow, reliable operation, and the ability to pump a wide variety of viscous, chemically aggressive, abrasive and impure liquids.

They are used in many industries such as mining, petro-chemical, pulp and paper and others. An air valve directs pressurized air to one of the chambers, this pushes the diaphragm across the chamber and fluid on the other side of the diaphragm is forced out. The diaphragm in the opposite chamber is pulled towards the centre by the connecting rod. This creates suction of liquid in chamber, when the diaphragm plate reaches the centre of the pump it pushes across the Pilot Valve rod diverting a pulse of air to the Air Valve.

This moves across and diverts air to the opposite side of the pump reversing the operation. It also opens the air chamber to the exhaust.

Dilatant : The property of a fluid whose viscosity increases with strain or displacement. For more information see non-newtoninan fluids. Discharge Static Head : The difference in elevation between the liquid level of the discharge tank if the pipe end is submerged and the centerline of the pump.

If the discharge pipe end is open to atmosphere than it is the difference between the pipe end elevation and the suction tank fluid surface elevation. This head also includes any additional pressure head that may be present at the discharge tank fluid surface, for example as in a pressurized tank.

See this tutorial for more information on discharge static head. Double suction pump : the liquid is channeled inside the pump casing to both sides of the impeller. This provides a very stable hydraulic performance because the hydraulic forces are balanced. The impeller sits in the middle of the shaft which is supported on each end by a bearing. Also the N. They are used in a wide variety of industries because of their reliabilty.

Another important feature is that access to the impeller shaft and bearings is available by removing the top cover while all the piping can remain in place. This type of pump typically has a double volute. Double volute pump : a pump where the immediate volute of the impeller is separated by a partition from the main body of the casing. This design reduces the radial load on the impeller making the pump run smoother and vibration free. For more information see this pdf file from Cornell Pumps.

Drooping curve : similar to the normal profile except at the low flow end where the head rises then drops as it gets to the shut-off head point. Efficiency: : the efficiency of a pump can be determined by measuring the torque at the pump shaft with a torque meter and then calculating the efficiency based on the speed of the pump, the pressure or total head and flow produced by the pump.

The standard equation for torque and speed provides power. The power consumed by the pump is proportional to total head, flow, specific gravity and efficiency. The efficiency is calculated for various flow rates and plotted on the same curve as the pump performance or characteristic curve. When several performance curves are plotted, the equal efficiency values are linked to provide lines of equal efficiency. This is a useful visual aide as it points out areas of the various pump curves that are at high efficiency, which will be the preferred areas or areas that the selected pump should operate within.

The highest efficiency on a given pump curve is known as the B. Centrifugal pumps come in many designs and some are more suitable for low-flow high-head applications and others for high-flow low-head and some in between. They are designed to achieve their maximum efficiency to accommodate a particular application.

The specific speed number gives an indication of what type of pump is more suited to your application. The effect of specific speed on pump design and how to calculate this number is available in this area of the visual glossary. It is possible to predict efficiency. Some years ago, a survey of typical industrial pumps was made. The average efficiency was plotted against the specific speed and it shows what the ultimate efficiency limits are for pumps under various operating conditions.

More information is available on the centrifugal pump tips page. Suction specific speed is another parameter that can affect efficiency. This number is a measure of how much flow can be put through a pump before it starts to choke reaches it's upper flow limit and cavitates the pressure at the suction becomes low enough that the fluid vaporizes.

More information is available in the visual glossary here. End suction pump : a typical centrifugal pump, the workhorse of industry. Also known as volute pump, standard pump, horizontal suction pump. The back pull out design is a standard feature and allows easy removal of the impeller and shaft with the complete drive and bearing assembly while keeping the piping and motor in place.

Impeller, vanes, vane tips, backplate, frontplate shroud , back vanes, pressure equalising passages or balancing holes. Equivalent length : a method used to establish the friction loss of fittings see next figure. The equivalent length of the fitting can be found using the nomograph below. The equivalent length is then added to the pipe length, and with this new pipe length the overall pipe friction loss is calculated.

This method is rarely used today. See tutotial3. Expeller : a hydro-dynamic seal that provides a seal without addition of water to the gland, specially useful for liquid slurries. External Gear pump : a positive displacement pump. Two spur gears are housed in one casing with close clearance. Liquid is trapped between the gear tooth spaces and the casing, the rotation of the gears pumps the liquid. They are also used for high pressure industrial transfer and metering applications on clean, filtered, lubricating fluids.

Flat curve : head decreases very slowly as flow increases, see centrifugal-pump-tips. Flow splitter : see suction flow splitter. Foot valve : a check valve that is put on the end of the pump suction pipe, often accompanied with an integrated strainer. Forum : the pumpfundamentals forum is a place where you can ask questions on centrifugal pumps and other types and also share you knowledge with others.

A valuable resource. Join here. Friction loss pump : the following chart shows the distribution of friction losses and their relative size that occur in a pump. Stepanoff published by John Wiley and Sons Friction pipe : The force produced as reaction to movement. All fluids are subject to friction when they are in motion. The higher the fluid viscosity, the higher the friction force for the same flow rate. Friction is produced internally as one layer of fluid moves with respect to another and also at the fluid wall interface.

Rough pipes will also produce high friction. Friction head loss pipe : the friction head loss is given by the Darcy-Weisbach equation and in many tables such as provided by the Cameron Hydraulic data book. It is normally given in feet of fluid per feet of pipe. Friction factor f pipe : the friction factor f is required for the calculation of the friction head loss.

It is given by the Moody diagram , or the Colebrook equation or the Swamee-Jain equation. The value of the friction factor will depend on whether the fluid flow is laminar or turbulent.

These flow regimes can be determined by the value of the Reynolds number. Hazen-Williams equation : this equation is now rarely used but has been much used in the past and does yield good results although it has many limitations, one being that it does not consider viscosity.

It therefore can only be applied to fluids with a similar viscosity to water at 60F. It has been replaced by the Darcy-Weisbach and the Colebrook equation.

The C coefficients use in the above Hazen-Williams equation are given in the table below. The source of this equation is the Cameron Hydraulic Data book. Head: the height at which a pump can displace a liquid to. Head is also a form of energy. In pump systems there are 4 different types of head: elevation head or static head, pressure head, velocity head and friction head loss. For more information on head see this tutorial.

Also known as specific energy or energy per unit weight of fluid, the unit of head is expressed in feet or meters. Try this web app to obtain head from pressure. Hydraulic gradient: All the energy terms of the system for example velocity head and piping and fitting friction loss are converted to head and graphed above an elevation drawing of the installation. It helps to visualize where all the energy terms are located and ensure that nothing is missed.

Impeller: The rotating element of a pump which consists of a disk with curved vanes. The impeller imparts movement and pressure to the fluid. The impeller consists of a back plate, vanes and for closed impellers a front plate or shroud. It may be equipped with wear rings, back vanes and balancing holes. Impeller eye: that area of the centrifugal pump that channels fluid into the vane area of the impeller. The diameter of the eye will control how much fluid can get into the pump at a given flow rate without causing excessive pressure drop and cavitation.

For more information on pump part terminology see this web page. Inducer: an inducer is a device attached to the impeller eye that is usually shaped like a screw that helps increase the pressure at the impeller vane entrance and make viscous or liquids with high solids pumpable.

The internal gear pumping principle was invented by Jens Nielsen, one of the founders of Viking Pump. It uses two rotating gears which un-mesh at the suction side of the pump to create voids which allow atmospheric pressure to force fluid into the pump. The spaces between the gear teeth transport the fluid on either side of a crescent to the discharge side, and then the gears re-mesh to discharge the fluid. Viking's internal gear design has an outer drive gear rotor- shown in orange which turns the inner, driven gear idler-shown in white.

Jet pump : a jet pump is a commonly available residential water supply pump. It has an interesting clever design that can lift water from a well up to 25 feet and allow it to function without a check valve on the suction and furthermore does not require priming. The heart of the design is a venturi source of water is from the discharge side of the impeller that creates low pressure providing a vacuum at the suction and allowing the pump to lift fluids. K factor : a factor that provides the head loss for fittings.

It is used with the following equation. The K factor for various fittings can he found in many publications. The type of fitting dictates the relationship between the friction loss and the pipe size.

Note: this method assumes that the flow is fully turbulent see the demarcation line on the Moody diagram of Figure 9.

Figure 7 Values for the K factor with respect to the friction factor for a standard tee. The Crane technical paper gives the K value for a fitting in terms of the term f T as in this example for a standard tee. As is the case for the data shown in Figure 6, the friction loss for fittings is based on the assumption that the flow is highly turbulent, in fact that it is so turbulent that the Reynolds number is no longer a factor and pipe roughness is the main parameter affecting friction.

This can be seen in the Moody diagram. There is a line in the diagram that locates the position where full turbulence starts. The term f T used by Crane is the friction factor and is the same as that given by the Colebrook or the Swamee-Jain equation.

When the Reynolds number becomes large the value of f T using the Swamee-Jain equation becomes:. Therefore, the previous equation for f T becomes:. Therefore the value of the K factor is easily calculated based on the diameter of the fitting, the friction factor f T and the multiplication factor for each type of fitting. It is characterized by fluid particles in layers moving past one another without mixing.

Lobe pump : a positive displacement pump. Primarily used in food applications because they handle solids without damaging them. Lobes are driven by external timing gears as a result the lobes do not make contact.

Liquid travels around the interior of the casing in the pockets between the lobes and the casing, meshing of the lobes forces liquid through the outlet port under pressure.

They also offer continuous and intermittent reversible flows and can operate dry for brief periods of time. Mechanical seal : a name for the joint that seals the fluid in the pump stopping it from coming out at the joint between the casing and the pump shaft.

A mechanical seal is a sealing device which forms a running seal between rotating and stationary parts. They were developed to overcome the disadvantages of compression packing. Leakage can be reduced to a level meeting environmental standards of government regulating agencies and maintenance costs can be lower. Mercury Hg : A metal that remains liquid at room temperature. This property makes it useful when used in a thin vertical glass tube since small changes in pressure can be measured as changes in the mercury column height.

The inch of mercury is often used as a unit for measuring vacuum level or pressures below atmospheric pressure. What is the B. However, if a pump operates at shut off, it could overheat badly. Operation in such regions should be avoided. The suction energy level of the pump increases with:.

Anything that increases the velocity of the pump impeller eye, the rate of flow of the pump, or the specific gravity, increases the suction energy of the pump. Each frame size for example frame T is built to specified dimensions. The amount of room required for the pump assembly will depend on the size and construction of the motor. It is easy to find a chart that provides the motor dimensions vs.

Moody diagram : A graphical representation of the laminar and turbulent Colebrook flow equations. Figure 9 the Moody diagram, a graphical representation of the laminar flow equation and the Colebrook equation for the friction factor f. The head or specific energy at the pump suction flange less the vapor pressure head of the fluid.

See this web app calculator for N. The manufacturers estimate on the NPSH required for the pump at a specific flow, total head, speed and impeller diameter. This is determined my measurement. For a larger scale image download npshr-predict. Newtonian fluid : A fluid whose viscosity is constant and independent of the rate of shear strain.

For Newtonian fluids, there is a linear relationship between the rate of shear and the tangential stress between layers. If you want to understand what a non-Newtonian fluid feels like and what it means for viscosity to change with the rate of shear, try this experiment.

In a large shallow bowl make a solution of approximately 1 part water and 2 parts corn starch, try moving this fluid rapidly around with your fingers. When the fingers are moved slowly, the solution behaves as expected, offering little resistance. The faster you try to move through the fluid, the higher the resistance. At that rate of shear, the solution almost behaves as a solid, If you move your fingers fast enough they will skip over the surface.

This is what is meant by viscosity being dependent on rate of shear. Compare this behavior to that of molasses; you will find that even though molasses is viscous its viscosity changes very little with the shear rate. Molasses flows readily no matter how fast the movement. See a video presentation of this experiment. Operating point : The point flow rate and total head at which the pump operates. It is located at the intersection of the system curve and the performance curve of a pump.

It corresponds to the flow and head required for the process. Peripheral regenerative pump : also known as regenerative or regenerative turbine pump. The impeller has short vanes at the periphery and these vanes pass through an annular channel.

The fluid enters between two impeller vanes and is set into a circular motion, this adds energy to the fluid particles which travel in a spiral like path from the inlet to the outlet. Each set of vanes continuously adds energy to the fluid particles. Peripheral pumps are more efficient at these low flow high head conditions than centrifugal pumps, they also require much less NPSHA than an equivalent centrifugal pump.

For a good explanation of the principal of operation see this page from the Mepco web site and also from the Roth Pump Co. Performance curve : A plot of Total Head vs. For more information on performance or characteristic curve see this tutorial. Pipe roughness : A measurement of the average height of peaks producing roughness on the internal surface of pipes.

Roughness is measured in many locations and then averaged, it is usually defined in micro-inches RMS root mean square. Download or view a pipe roughness chart in pdf format. Piping pressure maximum : it may be necessary in certain applications to check the maximum rating of your pipes to avoid bursting due to excessive pressure. Also the pipe flange rating will have to be checked. Pitot pump : also know as rotating casing pump. It is frequently used for high pressure shower supply on paper machines.

Pressure : The application of a force to a body producing more or less compression within the liquid. In a static fluid pressure varies with height. Fluid weight is the cause of hydrostatic pressure.

A thin slice of fluid is isolated so that the forces surrounding it can be visualized. If we make the slice very thin, the pressure at the top and bottom of the slice will be the same. The slice is compressed top and bottom by force vectors opposing each other.

The fluid in the slice also exerts pressure in the horizontal direction against the pipe walls. These forces are balanced by stress within the pipe wall. The pressure at the bottom of the slice will be equal to the weight of fluid above it divided by the area.

The pressure p is equal to the fluid weight F divided by the cross-sectional area A at the point where the pressure is calculated :. Pressure head : an expression of energy, specifically it is energy per unit weight of fluid displaced. More information on pressure head. We often need to calculate the pressure head that corresponds to the pressure.

Pressure can be converted to pressure head or fluid column height for any fluid. However, not all fluids have the same density. Water for example has a density of Specific gravity is the ratio of the fluid density to water density at standard conditions. By definition water has a specific gravity SG of 1. To convert pressure to pressure head, the specific gravity SG of the fluid must be known.

The specific gravity of a fluid is:. The constant gc is required to provide a relationship between mass in lbm and force in lbf. After simplification, the relationship between the fluid column height and the pressure at the bottom of the column is:. Progressive cavity pump : a positive displacement pump. These pumps are ideal for fluids that are just too tough for other pumps to handle.

They consist of only one driven metal rotor rotating within an elastomer lined elastic stator. Liquid acts as the lubricant between the pumping elements. Pseudoplastic : The property of a fluid whose viscosity increases slowly with rate of shear. Pumps as turbines PAT : Pumps used in reverse to act as turbines.

For more information see pumps as turbines. Radial flow pump : refers to the design of a centrifugal pump for medium head and medium flow or high head and low flow. The value of the specific speed number will provide an indication whether a radial pump design is suitable for your application. Radial vane pump : also known as partial emission pump or vane pump.

A frame mounted, end suction, top centerline discharge, ANSI pump designed specifically to handle corrosive chemicals at low flows. Recessed impeller pump : sometimes known as vortex pump. This is a frame-mounted, back pull-out, end suction, recessed impeller, tangential discharge pump designed specifically to handle certain bulky or fibrous solids, air or gas entrained liquids or shear sensitive liquids.

Recirculation : at low flow and high flow compared to the flow at the B.