Pump

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Pumps are devices that move liquids (liquids or gases), or sometimes slurries, by mechanical action. Pumps can be classified into three broad groups according to the methods they use to move liquids: direct transport , displacement , and gravity pumps.

The pump operates with several mechanisms (usually reciprocating or rotary), and consumes energy to perform mechanical work by moving the fluid. Pumps operate through many energy sources, including manual operations, electricity, machinery, or wind power, coming in a variety of sizes, from microscopes to use in medical applications for large industrial pumps.

Mechanical pumps serve a wide range of applications such as pumping water from wells, aquarium filtration, pond and aeration filters, in the car industry for water cooling and fuel injection, in the energy industry for pumping oil and natural gas or to operate tower cooling. In the medical industry, pumps are used for biochemical processes in the development and manufacture of drugs, and as artificial replacements for body parts, especially artificial heart and penile prosthesis.

When the casing contains only one rotating impeller, it is called a one-stage pump. When a casing contains two or more rotating impellers, this is called a double or multi-stage pump.

In biology, various types of chemical and bio-mechanical pumps have evolved, and biomimicry is sometimes used in developing new types of mechanical pumps.

Video Pump

Type

The mechanical pump may be submerged in liquids that are pumped or placed externally into the liquid.

Pumps can be classified by their transfer method to positive displacement pumps, impulse pumps, speed pumps, gravity pumps, steam pumps, and pumps without pumps. There are two basic types of pumps: positive displacement and centrifugal. Although axial flow pumps are often classified as separate types, they basically have the same operating principle as a centrifugal pump.

Positive displacement pump

The positive displacement pump makes fluid movement by trapping a fixed amount and forcing (displacing) the trapped volume into the exhaust pipe.

Some positive displacement pumps use a cavity that extends on the suction side and the cavity decreases on the discharge side. The liquid flows into the pump because the cavity on the suction side expands and the liquid flows out of the discharge when the cavity collapses. Volume is constant through each operating cycle.

Behavior and safety of positive displacement pump

Positive displacement pumps, unlike centrifugal or roto-dynamic pumps, can theoretically produce the same flow at a given speed (RPM) no matter what the discharge pressure is. Thus, the positive displacement pump is a constant flow machine . However, a slight increase in internal leakage due to increased pressure prevents a truly constant flow rate.

The positive displacement pump should not operate against the closed valve on the discharge side of the pump, since it does not have a centrifugal pump head cover. A positive displacement pump operating on a closed exhaust valve continues to produce flow and pressure in the exhaust line increases until the line erupts, the pump is severely damaged, or both.

A support or safety valve on the positive displacement pump discharge side is required. The relief valve can be internal or external. Pump manufacturers usually have the option of providing an internal safety valve or safety valve. Internal valves are usually used only as a security precaution. External relief valves in the sewer, with lines back to suction ducts or supply tanks provide increased security.

Positive displacement type

Positive displacement pumps can be further classified according to the mechanism used to move fluids:

Positive rotational rotation : internal gear, screws, shuttle blocks, flexible propellers or shear propellers, circular pistons, flexible impellers, helical crooked roots (eg Wendelkolben pump) or liquid-pump left
Reciprocating-type positive displacement: piston pump, propeller pump or diaphragm pump
Linear-type positive displacement: string pump and chain pump

Pump positive rotation pump

These pumps move the fluid using a rotating mechanism that creates a vacuum that catches and pulls in the liquid.

Advantages: Swivel pumps are very efficient because they can handle very thick liquids with higher flow rates due to increased viscosity.

Weaknesses: The nature of the pump requires very close distances between the rotating pump and the outer edge, making it rotate at a slow and stable speed. If the rotary pump is operated at high speeds, the liquid causes erosion, which in turn causes a wider clearance that can be passed by the liquid, which reduces efficiency.

Rotary positive displacement pump is divided into three main types:

Gear pump - a simple type of swivel pump where liquid is pushed between two gears
The screw pump - the internal shape of the pump is usually two back-backed screws for pumping liquids
The rotary vane pump - similar to a compressor scroll, has a cylindrical rotor wrapped in a similarly shaped house. As the rotor orbits, the trap propeller fluid between the rotor and the casing, draws the liquid through the pump.

Reciprocating positive displacement pump

The reciprocating pump moves the fluid using one or more oscillating pistons, plungers, or membranes (diaphragm), while the valve restricts fluid movement in the desired direction. In order for suction to take place, the pump must first pull the plunger into outward motion to lower the pressure in the chamber. Once the pusher pushes back, it will increase the pressure chamber and the inward pressure of the pusher will then open the exhaust valve and release the liquid to the delivery pipe at high speed.

Pumps in this category range from simplex , with one cylinder, in some cases quad (four) cylinders, or more. Many reciprocating pump types are duplex (two) or triplex (three) cylinders. They can be either single acting with suction for one direction of motion and piston release on the other side, or double action by suctioning and discharging in both directions. Pumps can be manually activated, by air or steam, or with machine-driven belts. This type of pump was used extensively in the 19th century - in the early days of steam propulsion - as a boiler feed water pump. Now reciprocating pumps usually pump very viscous liquids such as concrete and heavy oils, and serve in special applications that demand low flow rates against high resistance. Recipipating hand pumps are widely used for pumping water from wells. General bicycle pumps and foot pumps for inflation use reciprocal action.

These positive displacement pumps have an enlarged cavity on the suction side and a descending cavity on the expenditure side. The liquid flows to the pump because the cavity on the suction side expands and the liquid flows out of the discharge as the cavity collapses. The constant volume is given every operating cycle and the volumetric efficiency of the pump can be achieved through routine maintenance and inspection of the valve.

Common reciprocating pumps are:

Propeller pump - reciprocating plunger pushes the fluid through one or two open valves, covered with suction on the way back.
Diaphragm pump - is similar to a propeller pump, in which the plunger presses the hydraulic oil used to flex the diaphragm in the pumping cylinder. The diaphragm valve is used to pump harmful and toxic liquids.
Piston pumps displacement pumps - usually a simple device for pumping a small amount of liquid or gel manually. Common hand soap dispensers are such pumps.
Radial piston pump - a hydraulic pump shape in which the piston extends toward the radial.

Various positive-displacement pump

The principle of positive displacement applies in this pump:

Swivel lobe pump
Progressive cavity pump
Swivel gear pump
Piston pump
Diaphragm pump
Screw Pump
Gear pump
Hydraulic pump
Swivel propeller pump
Peristaltic pump
Strap pump
Flexible impeller pump

Gear pump

This is the simplest rotary positive displacement pump. It consists of two serrated teeth that rotate in a tight casing. The dental chambers trapped the fluid and forced it around the outer periphery. The liquid does not move back on the part of the braided, because the teeth cling tightly in the middle. The gear pump sees widespread use in automobile engine oil pumps and in various hydraulic power packages.

Screw Pump

The screw pump is a more complex type of rotary pump that uses two or three screws with the opposite thread - for example, one screw rotates clockwise and the other counterclockwise. The screws are mounted on a parallel shaft that has a gear that connects so that the shaft rotates together and everything stays in place. Screws turn on the shaft and move the liquid through the pump. As with any other form of rotary pump, the distance between the moving parts and the pump case is minimal.

Advanced cavity pump

Widely used for pumping difficult materials, such as contaminated waste sludge with large particles, this pump consists of a helical rotor, about ten times longer than its width. It can be visualized as a central core diameter x with, usually, a curved spiral wound around a half thickness x , although in fact it is produced in a single casting. This shaft fits inside the heavy duty rubber arm, the wall thickness is also usually x . As the shaft rotates, the rotor gradually pushes fluid to the rubber sleeve. Such pumps can develop very high pressures at low volumes.

Pump type root

Named after the Roots brothers found it, this lobe pump replaces the trapped fluid between two long helical rotor, each mounted to the other when perpendicular to 90 Â°, spinning in a triangular sealing line configuration, both at the suction point and at point of exile. This design produces a continuous flow with the same volume and no vortex. Can work with low pulsation speeds, and offers the soft performance that some applications require.

Applications include:

High Capacity Industrial Air Compressor
Roots superchargers on internal combustion engines.
Brand of civil defense sirens, Thunderbolt from Federal Signal Corporation.

Peristaltic pump

A peristaltic pump is a positive displacement pump type. It contains liquid in a flexible tube mounted inside a circular pump casing (although linear peristaltic pumps have been made). Any number of rolls , shoes , or wiper attached to the rotor presses a flexible tube. When the rotor changes, the part of the tube under compression closes (or clogged ), forcing the liquid to pass through the tube. In addition, when the tube is exposed to its natural state after the cam passes it pulls ( restitution) the liquid into the pump. This process is called peristaltic and is used in many biological systems such as the gastrointestinal tract.

Plunger Pump

Booster pump is a reciprocating positive transfer pump.

It consists of a cylinder with reciprocating plunger. The suction and disposal valves are installed in the cylinder head. At the suction step, the shortened plunger and open suction valve cause the suction of liquid into the cylinder. In advanced stroke, the plunger pushes out the liquid from the exhaust valve. Efficiency and common problems: With only one cylinder in the driving pump, the fluid flow varies between the maximum flow when the plunger moves through the center position, and the flow is zero when the plunger is in the final position. Much energy is wasted when fluid is accelerated in the piping system. Vibrations and water hammers may be a serious problem. In general the problem is compensated by using two or more cylinders that do not work in phase with each other.

Triplex-style thrust pump

The triplex booster pumps use three plungers, which reduce the pulse of a single reciprocating drive pump. Adding the pulse damper to the pump outlet can further smooth the pump ripple, or the ripple graph of the pump transducer. The dynamic relationship of high pressure liquids and plungers generally requires high-quality plunger seals. Plunger pumps with larger amounts of plunger have the benefit of increased flow, or smooth flow without pulsed dampers. Improved moving parts and crankshaft loads are one of the disadvantages.

Car washes often use triplex plunger pumps (possibly without pulsed dampers). In 1968, William Bruggeman reduced the size of the triplex pump and increased the lifetime so that car washes could use the equipment with a smaller footprint. Durable high-pressure seals, low-pressure seals and oil seals, hardened crankshafts, hardened connecting rods, thick ceramic plasterers and heavier duty spheres and roller bearings improve reliability in triplex pumps. Triplex pumps are now in a myriad of markets around the world.

Plywood pumps with shorter durability are common to home users. A person who uses a home pressure washer for 10 hours a year may be satisfied with a 100 hour pump that lasts between rebuilding. The industrial or continuous triplex duty grade pump at the other end of the quality spectrum can run up to 2,080 hours per year.

The oil and gas drilling industry uses a large semi-transport triplex pump called a mud pump to pump drilling mud, which cools the drill bit and brings cuttings back to the surface. The driller uses a triplex or even quintuplex pump to inject water and solvent deep into flakes in an extraction process called fracking .

Air compressive dual-diaphragm pump

One of the modern applications of positive displacement pumps is the compressor-powered dual-diaphragm pump. Running in compressed air of these pumps is intrinsically safe by design, although all manufacturers offer ATEX-certified models to comply with industry regulations. These pumps are relatively inexpensive and can perform a variety of tasks, from pumping water out of the bunds to pump hydrochloric acid from safe storage (depending on how the pump is manufactured - elastomers/body construction). These double diaphragm pumps can handle viscous liquids and abrasive materials with ideal pumping processes for transporting friction-sensitive media.

Pump rope

Designed in China as a chain pump more than 1000 years ago, this pump can be made from a very simple material: The ropes, wheels and PVC pipes are enough to make a simple rope pump. The efficiency of rope pumps has been studied by grassroots organizations and techniques to make and run them constantly improved.

Impulse pump

Impulse pumps use pressure made by gas (usually air). In some impulse pumps, gases trapped in liquids (usually water), are released and accumulated somewhere in the pump, creating pressure that can push some of the fluid upwards.

Conventional impulse pumps include:

Hydraulic ram pump - the kinetic energy of a low-water supply is stored temporarily in a water-bubble hydraulic accumulator, then used to move water to the higher head.

Pulser pumps - run with natural resources, with only kinetic energy.

Airlift Pump - runs in air inserted into the pipe, which pushes water upward when the bubble moves upward

Instead of gas accumulation and release cycles, pressure can be created by burning hydrocarbons. The combustion-fueled pump directly sends an impulse to form a combustion event through the actuation membrane to the pump fluid. To enable this direct transmission, the pump must be almost entirely made of elastomers (eg silicone rubber). Therefore, the combustion causes the membrane to expand and thereby pump the fluid out of the adjacent pump room. The first burn-driven soft pump was developed by ETH Zurich.

Hydraulic ram pump

A hydraulic ram is a water-driven pump.

It takes in water at relatively low pressure and high flow rate and water output at higher hydraulic level and lower flow rate. This device uses a water hammer effect to develop a pressure that lifts a portion of the input water that drives the pump to a higher point from where the water began.

Hydraulic ram is sometimes used in remote areas, where there is a low-powered hydro source, and the need to pump water to a higher destination than its source. In this situation, ram is often useful, since it requires no external resources other than the kinetic energy of running water.

Pump speed

The rotodynamic pump (or dynamic pump) is a type of speed pump in which the kinetic energy is added to the liquid by increasing the flow velocity. This energy increase is converted to potential energy (pressure) when the velocity decreases before or when the outflow from the pump to the discharge pipe. The conversion of kinetic energy to this pressure is explained by First Thermodynamic Law , or more specifically with the Bernoulli principle .

The dynamic pump can be subdivided according to the means by which the speed gain is achieved.

This type of pump has a number of characteristics:

Continuous energy

Convert additional energy to increase kinetic energy (increase in speed)

Convert speed increase (kinetic energy) to increased head pressure

The practical difference between dynamic and positive displacement pumps is how they operate under closed-valve conditions. The positive displacement pump physically replaces the liquid, so closing the downstream valve of the positive displacement pump produces a continuous pressure buildup that can cause mechanical failure of the pipe or pump. The dynamic pump is different because it can be operated safely under closed valve conditions (for short periods of time).

Radial flow pump

Such pumps are also referred to as centrifugal pumps. The liquid entering along the axis or center, is accelerated by the impeller and exits at right angles to the shaft (radically); An example is a centrifugal fan, which is usually used to implement a vacuum cleaner. Generally, radial flow pumps operate at higher pressures and lower flow rates than axial or mixed flow pumps.

Axial flow pump

These are also referred to as All fluid pumps. The fluid is pushed outward or inward and axially moving fluid. They operate at much lower pressures and higher flow rates than radial-flow (centripetal) pumps. The axial flow pump can not run until speed without special precautions. If at a low flow rate, the total head rise and high torque associated with this pipe would mean that the initial torque should be an acceleration function for the entire mass of fluid in the pipe system. If there is a large amount of liquid in the system, accelerate the pump slowly.

The mixed flow pump serves as a compromise between radial and axial pumps. The fluid undergoes radial acceleration and lifts and exits the impeller somewhere between 0 and 90 degrees from the axial direction. As a result the mixed flow pump operates at a higher pressure than the axial flow pump while providing a higher discharge than the radial flow pump. The outflow angle determines the characteristics of head-discharge pressure in relation to radial and mixed flow.

Jet-eductor pump

It uses jets, often steam, to create low pressure. This low pressure sucks fluid and pushes it into the higher pressure region.

Gravity pump

The gravity pump includes the siphon and the Heron fountain . The hydraulic ram is also sometimes called a gravity pump; in a gravity pump the water is lifted by the force of gravity.

Steam pump

Steam pumps have long been in the main interest. They include all types of pumps powered by steam engines and also pistonless pumps such as Thomas Savery's or Pulsometer steam pumps.

There has recently been a resurgence of interest in low-power solar steam pumps for use in smallholder irrigation in developing countries. Previously small steam engines have not been feasible due to increased inefficiency as steam engines decreased in size. But the use of modern engineering materials coupled with alternative machine configurations means that this type of system is now a cost-effective opportunity.

Pump without valve

Valless pumping helps in the transportation of fluids in a variety of biomedical systems and techniques. In the pump system without valves, no valves (or physical occlusion) are present to regulate the flow direction. The efficiency of pumping liquids from a valveless system, however, is not necessarily lower than having a valve. In fact, many fluid-dynamical systems are in nature and the technique is more or less dependent on valveless pumping to transport the working fluid inside. For example, blood circulation in the cardiovascular system is maintained to some extent even when the heart valve fails. Meanwhile, the heart of embryonic vertebrates begins to pump blood long before the development of space and the visible valve. In microfluidics, impedance pumps without currencies have been made, and are expected to be particularly suitable for handling sensitive biofuels. Ink jet printers that operate on the principle of Piezoelectric transducers also use valless pumps. The pump room is emptied through the printing jet because the flow impedance is reduced in that direction and recharged by the capillaries.

Maps Pump

Pump repair
Checking pump repair records and the average time between failures (MTBF) is very important for responsible and meticulous pump users. In light of that fact, the introduction to the 2006 Pump User Handbook alludes to the statistics of "pump failure". For convenience, these failure statistics are often translated to MTBF (in this case, install live before failure).
In early 2005, Gordon Buck, chief engineer of John Crane Inc. for Field Operations in Baton Rouge, LA, examined improved records for a number of refineries and chemical plants to obtain meaningful reliability data for centrifugal pumps. A total of 15 factories with nearly 15,000 pumps were included in the survey. The smallest factory has about 100 pumps; some factories have more than 2000. All facilities are located in the United States. In addition, it is considered "new", others as "updated" and others as "established". Many of these plants - but not all of them - have an alliance arrangement with John Crane. In some cases, the alliance contract includes having a technician or engineer John Crane Inc. in place to coordinate various aspects of the program.
However, not all plants are refineries, and different results occur elsewhere. In chemical factories, pumps are historically "thrown away" because chemical attacks limit life. Things have improved in recent years, but the limited space available in the "old" DIN and standard ASME stuffing boxes place limits on the type of matching seal. Unless the pump user updates the seal space, the pump accommodates only the simpler and simpler versions. Without this increase, endurance in chemical installations is generally about 50 to 60 percent of the value of the refinery.
Unscheduled maintenance is often one of the most significant cost of ownership, and the failure of mechanical seals and bearings is one of the main causes. Remember the potential value of pump picking that costs much earlier, but lasts longer between improvements. MTBF from better pumps may be one to four years longer compared to non-enhanced partners. Consider that the average rated pump failure rate published ranges from US $ 2600 to US $ 12,000. This does not include the opportunity cost lost. One pump fire occurred per 1000 failures. Having fewer pump failures means having fewer destructive pump fires.
As noted, a typical pump failure, based on a 2002 actual report, costs an average of US $ 5,000. This includes costs for materials, parts, labor and overhead. Extending the pump MTBF from 12 to 18 months will save US $ 1,667 per year - which is probably greater than the cost to increase the reliability of the centrifugal pump.
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Apps
Pumps are used throughout the community for various purposes. Early applications include the use of windmills or waterwheels to pump water. Currently, pumps are used for irrigation, water supply, gasoline supply, air conditioning systems, refrigeration (usually called compressors), chemical movement, waste movements, flood control, marine services, etc.
Due to the wide range of applications, the pump has a large number of shapes and sizes: from very large to very small, from gas handling to handling fluid, from high pressure to low pressure, and from high volume to low volume.
Priming pump
Usually, the liquid pump can not only draw air. The pump feed line and the internal body surrounding the pumping mechanism must first be filled with a fluid that requires pumping: The operator must insert the liquid into the system to start pumping. This is called a pumping priming. Losing prime is usually due to swallowing air into the pump. The free distance and the ratio of displacement in the pump to the liquid, whether thin or thicker, usually can not replace air due to its compressibility. This is the case with most speed pumps (rotodynamic) - for example, centrifugal pumps. For such pumps, the pump position should always be lower than the suction point, otherwise the pump must be manually filled with liquid or the secondary pump should be used until all air is removed from the suction duct and pump case.

Positive-displacement pumps, however, tend to have a fairly tight seal between moving parts and casing or housing of the pumps they can be described as self-priming . Such pumps can also function as priming pumps, called when used to meet the need for other pumps in lieu of action taken by human operators.

Pump as public water supply

One of the most common types of pumps in the world is hand-powered water pumps, or 'pitcher pumps'. It was generally installed on top of community water wells in the days before the tap water supply.

In some parts of the British Isles, it is often called the parochial pump . Although such community pumps are no longer common, people still use the expression of the parish pump to describe a place or forum in which issues of local interest are discussed.

Because the water from the pitcher pump is taken directly from the ground, it is more susceptible to contamination. If such water is not filtered and purified, it may cause gastrointestinal disease or other water-borne diseases. The famous case is the outbreak of Cholera 1858 Broad Street. At the time it was not known how cholera was transmitted, but doctor John Snow suspected contaminated water and had a public pump handle suspected of being released; the plague then subsided.

Hand-operated modern community pumps are considered the most sustainable low-cost option for safe water supply in resource-poor settings, often in rural areas of the developing world. Hand pumps open access to deeper, often less polluted soil water and also improve the safety of wells by protecting water sources from contaminated buckets. Pumps like the Afridev pump are designed to be cheap to build and install, and easy to maintain with simple parts. However, the scarcity of spare parts for these types of pumps in some parts of Africa has reduced their usefulness to these areas.

Pumping multiphase pumping app

The multiphase pump application, also referred to as tri-phase, has grown due to increased oil drilling activity. In addition, the multifase production economy is attractive to upstream operations as it leads to simpler installation in the field, reducing equipment costs and increasing production levels. In essence, the multifasa pump can accommodate all fluid flow properties with one piece of equipment, which has a smaller footprint. Often, two smaller multiphase pumps are installed in series rather than having only one large pump.

For midstream and upstream operations, multiphase pumps can be placed onshore or offshore and can be connected to one or more wellheads. Basically, multifase pumps are used to transport unreacted flow streams from oil wells to downstream processes or collection facilities. This means that the pump can handle the flow of wells from 100 percent of the gas to 100 percent fluid and any imaginable combinations in between. Stream flow can also contain abrasives such as sand and dirt. The Multiphase pump is designed to operate under changing or fluctuating process conditions. Multiphase pumping also helps eliminate greenhouse gas emissions because operators seek to minimize gas combustion and tank ventilation if possible.

Types and features of multiphase pump

Helico-axial (centrifugal) pump

Rotodynamic pumps with a single shaft requiring two mechanical seals, this pump uses an open axial impeller. This is often called the Poseidon pump, and can be described as a cross between an axial compressor and a centrifugal pump.

Twin-screw (positive-displacement)

The twin-screw pump is built from two inter-meshing screws that move the pumped liquid. Twin screw pumps are often used when pumping conditions contain high volume gas fractions and fluctuating inlet conditions. Four mechanical seals are required to seal two axes.

Progressive (positive-displacement) cavity

When the pumping application is not suitable for centrifugal pumps, progressive cavity pumps are used instead. Progressive cavity pump is a type of single screw normally used in shallow wells or on the surface. This pump is mainly used in surface applications where pumped liquids may contain large amounts of solids such as sand and dirt. The volumetric efficiency and mechanical efficiency of the progressive cavity pump increases with fluid viscosity.

Electric submersible (centrifugal)

This pump is essentially a multistage centrifugal pump and is widely used in oil well applications as a method for artificial removal. This pump is usually determined when the liquid is pumped primarily liquid.

Buffer Tank The buffer tank is often installed upstream from the pump suction nozzle in the event of a slug flow. The buffer tank breaks the energy of the snail fluid, smoothing all fluctuations in the inlet flow and acting as a sand trap.

As the name suggests, multifase pumps and mechanical seams can experience great variations in service conditions such as changes in process liquid composition, temperature variations, high and low operating pressures and exposure to abrasive/erosive media. The challenge is to choose the right mechanical seal arrangement and support system to ensure maximized seal life and overall effectiveness.

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Specifications

Pumps are usually rated by horsepower, volumetric flow rate, outlet pressure in meters (or feet) of the head, suction suction on the suction foot (or meter) of the head. The head can be simplified as the number of feet or pump meters can raise or lower the water column at atmospheric pressure.

From an early design point of view, engineers often use a quantity called special velocity to identify the type of pump most suitable for a certain combination of flow rate and head.

Everbilt 1/2 HP Sewage Pump-ESE50W-HD - The Home Depot

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Pumping power

The power put into liquid increases the liquid energy per unit volume. Thus the power relation is between the mechanical energy conversion of the pump mechanism and the liquid elements inside the pump. In general, this is governed by a series of simultaneous differential equations, known as Navier-Stokes equations. But a simpler equation relates only to the different energies in the liquid, known as the Bernoulli equation can be used. Therefore power, P, is required by the pump:

{\ displaystyle P = {\ frac {\ Delta pQ} {\ eta}}}

Where? p is the total pressure change between the inlet and outlet (in Pa), and Q, the volume flow rate of the liquid is given in m ³/s. The total pressure may have gravitational components, static pressure and kinetic energy; ie the energy is distributed between changes in gravitational potential energy (up or down hill), changes in velocity, or changes in static pressure. ? is the pump efficiency, and may be provided by the manufacturer's information, as in the form of a pump curve, and usually derived from a fluid dynamics simulation (ie a solution for Navier-Stokes for a particular pump geometry), or by testing. The efficiency of the pump depends on the pump configuration and operating conditions (such as rotation speed, fluid density and viscosity, etc.)

{\ displaystyle \ Delta P = {{v_ {2} ^ {2} -v_ {1} ^ {2}) \ over 2} \ Delta zg {\ Delta p_ {mathrm {static}} \ over \ rho}}

For typical "pumping" configurations, work is applied to the fluid, and thus positive. For fluids that provide work on the pump (ie turbine), the work is negative. The power required to drive the pump is determined by dividing the output power by pump efficiency. Furthermore, this definition includes pumps without moving parts, such as siphon.

How does a Centrifugal pump work ? - YouTube

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Efficiency

The efficiency of the pump is defined as the ratio of power applied to the fluid by the pump in relation to the power supplied to drive the pump. The value is not fixed for the given pump, efficiency is a function of the discharge and therefore also operates the head. For centrifugal pumps, efficiency tends to increase with the flow rate up to the midpoint through the operating range (peak efficiency or the Best Efficiency Point (BEP)) and then decreases as the flow rate rises further. Such pump performance data is usually given by the manufacturer before pump selection. The efficiency of the pump tends to decrease over time due to wear and tear (eg increase in clearance as the impeller reduces the size).

When a system inserts a centrifugal pump, an important design issue is to match the head loss-flow characteristics with the pump so that it operates at or near its maximum efficiency point.

Pump efficiency is an important aspect and pumps should be tested regularly. The thermodynamic pump test is one of the methods.

Submersible Sump Pumps - Sump Pumps - The Home Depot