Pumps are used to transfer fluids from one area to another. They most commonly convert electrical energy into hydraulic energy. The pumps have multiple types designed according to the requirements of different applications. In this article, you will learn the different types of pumps, the working of the water pump, and the function of the pump.
What is a Pump?
A pump is a mechanical device that is used to transfer different fluids (gases or liquids) from one location to another by applying mechanical action. The pumps most commonly convert electrical energy into hydraulic energy to transfer fluids.
The hydraulic pump can also be utilized in processes that require high hydraulic pressure. You can easily find them with heavy equipment. In general, heavy equipment needs lower suction pressures and high discharge pressures.
Pumps are driven by means of different power sources such as wind power, solar power, engine, or manual operation. They are usually worked by a vacuum in which air pressure pushes the liquid out. All types of pumps work by producing a low-pressure area on the inlet side.
The low pressure on the pump’s inlet side causes the fluid to rise from a particular depth and the high pressure on the outlet side pushes the fluid to the desired head.
A pump has similar working to a compressor. The main difference between them is that they are used for different working fluids.
Types of Pump
The pumps have the following major types:
- Positive Displacement Pump
- Dynamic Pump
1) Positive Displacement Pump
Main Article: Positive Displacement Pumps
The positive displacement pumps most commonly use moving parts (such as gears, lobes, plungers, pistons, or rotors) to transfer the fluids. The moving parts of these pumps discharge the fluid from the pump housing and increase the hydraulic pressure at the same time.
They operate by trapping a specific amount of liquid in the pump chamber through an inlet valve and expelling it via the discharge valve. These pumps don’t need manual priming because they have self-priming ability.
The positive displacement pumps are further divided into multiple types. The classification of the positive displacement pumps is given below:
1.1) Reciprocating Pumps
Main Article: Reciprocating Pump
These types of pumps use a plunger or piston to transfer the fluids. The piston or plunger moves downward and upward inside the pump cylinder. The piston or plunger is connected to the crankshaft through a connecting rod. The crankshaft is connected to an electrical motor or engine that helps to rotate the crankshaft.
This type of pump pumps the fluids in two strokes: suction stroke and discharge stroke. During the suction stroke, the cylinder is filled with fresh liquid. After filling the cylinder, the inlet valve closes, and the discharge stroke starts.
During the discharge stroke, the outlet valve opens, and pressurized liquid discharges from the outlet valve. The inlet and outlet sides have a check valve for preventing the backward flow of the liquid.
The reciprocating pump is one of the most effective types of pump. They are most commonly used in petrochemical, oil & gas, refinery, agriculture, and fertilizer industries.
Advantages and Disadvantages of Reciprocating Pump
| Advantages | Disadvantages |
| It creates large pressure than a centrifugal pump. | These pumps are not best for high-flow applications because it produces a low flow rate. |
| It is best for high-pressure requirement applications. | It has a high initial cost because it uses a large number of components. |
| Because it uses a piston and cylinder for pressurizing the fluid, therefore, it has easy operation. | It can’t deliver a continuous supply of water or other fluids. |
| It has a self-priming capability. | Due to the large number of components, it has a high weight. |
| It has high efficiency. | The friction between the piston and cylinder is high; therefore, a reciprocating pump has high wear & tear. |
| It can also use for air compression. | It has a high maintenance cost. |
The reciprocating pumps are further divided into the following types:
1.1.1) Plunger Pumps
The plunger pump has a crosshead operated by a cam handle device. The capacity of this pump is adjusted by varying its speed or the number of strokes. You can change the stroke through the setting of the eccentric pin.
The plunger pump uses a plunger instead of a piston. They are driven by electric, hydraulic, pneumatic, or steam-powered drives.
These types of pumps are used for scum, sludge, water jet machining, sewage, and clarifier concentrator underflow applications.
The plunger pumps are mostly used for applications such as descaling, oil hydraulics, cleaning, water irrigation, and transporting paints, chocolates, pastries, etc.
Advantages and Disadvantages of Plunger Pumps
| Advantages | Disadvantages |
| It consumes low energy. | It delivers a pulsating flow of fluid. |
| Linear performance curve. | It can handle only those fluids that have a low flow rate. |
| It has the maximum possible efficiency. | These pumps have high maintenance costs. |
| It has a wide range of pressure. | These have a large size. |
| It has the capability to move in slurries, high-viscosity liquids, and abrasives with good control. | They require high space for installation. |
1.1.2) Diaphragm Pumps
The diaphragm pump is a versatile type of pump. It uses a combination of Teflon, thermoplastic, or reciprocating rubber diaphragms. These pumps usually use a rubber membrane and work on the air displacement principle.
These pumps have the ability to handle a large number of liquids, including dry food powders, wastewater, additives, pharmaceuticals, and chemicals.
The main advantage of the diaphragm pump is that it does not require any packing or seals. Therefore, these types are most commonly used in leakage-free applications. These pumps are designed for pumping sludge, slurries, and liquids.
These pumps are used for mining, industrial and general plants.
Advantages and Disadvantages of Diaphragm Pumps
| Advantages | Disadvantages |
| It has a self-priming capability. | It can’t supply high pressure during the pumping process. |
| These pumps have easy installation. | It is less reliable in the supply of fluid during the pumping process. |
| These are portable. | The costs of the spare parts are very high |
| A diaphragm pump has a long service life. | It has a high initial cost. |
| These can handle fluids with low, medium, and high viscosities. | In some cases, it takes a large time for product delivery. |
| It doesn’t have seal problems. |
Read More: Diaphragm Pump Working and Applications
1.1.3) Piston Pumps
The piston pump is a simple and powerful device. It uses a piston instead of a plunger. It has a piston, a cylinder, a casing, and a series of control units. The piston is connected to the crankshaft through a connecting rod. The piston of this pump gets power from an electric motor via a crankshaft.
The piston pumps are operated by moving the piston upward and downward inside the pump cylinder. As the piston moves downward, it sucks the fluid while it moves upward then it pressurizes the fluid.
During the piston’s downward movement, the pump sucks water or other fluid from the outside via an inlet valve. During the upward movement, the piston increases the pressure of the fluid by reducing its volume.
The piston pumps are used for applications such as withdrawing water from the well or depth of the earth, reliable pressure, water irrigation, oil & gas, and distribution systems for transporting paint, pastry, chocolate, etc.
1.2) Rotary Pump
The rotor of the rotary pump transfers the fluid by orbiting and rotatory movement. The rotary pump mechanism consists of housing, vane, cams, runner, inlet, and outlet ports. These components of the rotary pump help to transfer fluids.
These are self-priming pumps and offer an almost constant delivery rate regardless of the pressure.
They are manufactured with a minimum clearance between the stationary and rotating components for minimizing leakage from the pressure side to the suction side. These pumps work at low speeds to sustain these clearances.
As the rotary pump operates at high speed, it causes excessive wear and erosion, resulting in larger clearance and reducing pump performance.
These pumps are most frequently used to transfer highly viscous fluids like oils, including handling lubricating oils and fuels, into the engine room.
The rotary pump has the following further types:
1.2.1) Rotary Lobe Pumps
The rotor of this type of pump does not touch the housing during its working. The liquid sucks in from the suction valve to the cavity between the chamber wall and the lobes. Due to the meshing of the rotors, the liquid can’t escape between them. Therefore, liquid exits from the nozzle along the rotation direction of the outer lobe.
These types of hydraulic pumps have various characteristics such as high reliability, hygienic quality, rust resistance, and excellent efficiency.
They are frequently used in the applications such as biopharmaceutical manufacturing, beverage & food processing, and hygienic processing industries.
Advantages and Disadvantages of Rotor Lobe Pump
| Advantages | Disadvantages |
| These pumps can handle pastes, slurries, solids, and many other liquids. | It requires two seals. |
| It doesn’t have metal-to-metal contact. | It requires timing gears. |
| It provides pulsating free flow. | Reduces lift with thin liquids. |
| This pump can run dry for a long time. | It has a high cost. |
1.2.2) Screw Pumps
The screw pump is a singular kind of positive displacement rotary pump in which the liquid flowing through the pump element is axial. It is a non-clog, large-capacity, atmospheric pressure device that can pump various wastes and solids from the original raw sewage.
However, these have many practical limitations regarding pumping the head. It uses two screws (driver and driven screws) for pumping the fluid. These screws mesh with each other. The driver screw is connected to an electric motor or engine. The driven screw gets power from the driver screw.
Advantages and Disadvantages of Screw Pumps
| Advantages | Disadvantages |
| Ir can operate in dry conditions. | It has a high cost. |
| This type of pump can use for all fluids. | It needs a gas blast to transfer light gases. |
| These pumps have a compact design. | It has a low pumping speed |
| Self-priming capability |
1.2.3) Progressive Cavity Pumps
These types of pumps are specially designed for the transportation of viscous and abrasive liquids with a high content of air, fibers, and solids. The rigid steel screw rotor spins and rotates in the elastomer stator.
They are best suitable for multiphase, nasty, tough liquids with solids and gas in suspension at comparatively medium temperatures. These are best for shear-sensitive liquids. These pumps can control both high and low-viscosity materials such as vegetables and fruits. They design for a volumetric flow rate that is proportional to the turning rate of the pump impeller.
Advantages and Disadvantages of Progressive Cavity Pumps
| Advantages | Disadvantages |
| These pumps are good for solids and other complex fluids. | It has high maintenance costs. |
| It has a self-priming capability | The alignment of the shaft is very hard to maintain. |
| It has a quiet operation. | Dry running even for a few seconds may damage the stator. |
| This pump may also operate vertically. | A liquid requires to maintain the sliding surfaces lubricated. |
| These are best for high and low-viscosity fluids. | This pump can only use to transfer fluids for a limited distance. |
1.2.4) Gear Pumps
The gear pumps use a series of gears to transfer the fluid. Gear pump usually has two gears: one gear knows as the idler gear or the driven gear and the second gear knows as the power or the driver gear. These gears mesh with each other.
The power gear gets power from the prime mover or a mechanical power source. An internal combustion engine, electric motor, or manual labor is used to rotate the power gear.
1.3) Pneumatic Pump
A pneumatic pump is a positive displacement pump. They use for the applications such as water treatment, food, and chemical companies. This pump provides a stable flow for mixing and measuring.
It also has the capacity of pumping various liquids such as toothpaste and multiple chemicals. In these pumps, pressurized air uses to move the fluid.
In the pneumatic ejector, pressurized air releases from the delivery pressure vessel to the outlet line by gravity through a sequence of surges via the check valve.
Advantages and Disadvantages of Pneumatic Pumps
| Advantages | Disadvantages |
| It has easy maintenance. | Because this pump uses compressed air instead of electricity, compressed air is more expensive than electricity. |
| It is easy to use. | It produces high operation during its operation. Therefore, a silencer is required to control its noise. |
| This pump has a low initial cost. | It is very important to make sure that there is no leakage in a pneumatic system because pressurized air leakage produces energy losses. |
| It requires a limited cleaning. | These systems are not friendly to work with smart electronics. |
2) Dynamic Pump
A dynamic pump transfers the fluid by increasing its pressure as it passes through the impeller and diffuser of the pump. In this type, the impeller increases the speed of the fluid and the diffuser converts this speed into pressure energy. It uses centrifugal force to transfer the fluids.
A dynamic pump further divides into the below-given types:
2.1) Centrifugal Pumps
These are the most widely used pumps around the world. The centrifugal pump has a simple working principle. These pump types are efficient, robust, and relatively inexpensive to manufacture.
It is a pump that uses an impeller and a diffuser for pumping the fluids. The impeller is connected to an electric motor via a crankshaft.
As the crankshaft starts its rotation, the impeller also rotates. This impeller has fixed blades that also rotate with the impeller movement. The impeller moves the fluid axially and radially with the help of a centrifugal force.
This impeller action increases the fluid pressure and velocity and also directs it toward the outlet. It has a specially designed casing that compresses the fluid from the pump inlet, directs it into the impeller, and controls it before discharging.
The centrifugal pumps are the best options for applications such as pharmaceutical, chemical, mining, oil, power plants, industrial, municipal (water and wastewater treatment plants), agriculture, etc.
The centrifugal pumps are most commonly used for sewage drainage, mud, sludge, crude oil pumping, hot water circulation, pressurization, water supply, and boiler water treatment.
The centrifugal pumps have the following types:
2.2.1) Radial Flow Pumps
It is one of the most famous types of centrifugal pumps. The impeller of these pumps discharges liquid at right angles to the shaft. With these types of pumps, the entire pressure generates by centrifugal force.
The radial flow pumps are used for low-flow rate and high-pressure applications. The runner outer diameter to the eye diameter ratio for this water pump is not less than 2.
2.2.2) Axial Flow Pumps
In the axial flow pump, the fluid moves through the runner in a parallel direction to the low height of the shaft axis.
These types of pumps are used for high discharge flow and medium head applications. They create pressure by pushing and lifting liquid with the impeller blade.
It has only one ratio of runner outer diameter (D2) to eye diameter (D1). Its impeller has no width.
2.2.3) Mixed Flow Pumps
In this pump, the direction of flow is partly radial and partly axial. It uses for high-flow and medium-head applications. In these, some of the pressure is created by centrifugal force, and some are created by lifting the impeller blades on the fluid.
A Mixed-flow pump mostly utilizes for drainage of agricultural land and lift irrigation, handling seawater, cooling water for nuclear and thermal power plants, water supply, industrial applications, and sewage applications.
It has less than 1.5 ratios of runner outer diameter (D2) to eye diameter (D1). Its impeller has a lot of widths.
2.2.4) Vertical Centrifugal Pumps
It is also known as a cantilever pump. It uses a unique maintenance design and exclusive shaft. This pump has a maintained design and a special shaft that allows the volume to fit in the pit when the bearing is outside the pit.
It does not use a filled container to cover the shaft but uses a throttle sleeve.
2.2.5) Horizontal Pumps
The horizontal water pump has at least two impellers. These use for pumping services.
All phases are in similar shelters and are mounted on similar axes. At least eight additional steps can be mounted on a single horizontal shaft. Each step lifts roughly the same amount of head. The multi-stage water pump can be primed double or single suction with the first impeller.
2.2.6) Submersible Pumps
These are close-coupled pumps driven by submersible motors. They are designed to install underwater in damp wells. The motor of this pump is installed under the bowl assembly and directly connected to the rotor shaft.
A submersible pump is also known as a septic tank pump, sewage pump, and rainwater pump. It has many applications, including construction, municipal, industrial, local, household, commercial, and storm-water recycling services.
These types of pumps are most commonly used to pump rainwater, groundwater, trade water, greywater, black water, sewage, well water, chemicals, and food.
Various designs of submersible pumps are available for different applications such as low head, high flow, high head, and low flow.
2.2.7) Line-shaft Pump
The controller of this type of motor connects to the ejection head. The shaft system extends through the column to the drum assembly. In this way, the shaft transfers the torque to the rotor of the water pump.
2.2) Special Effect Pumps
The special effect pump is also known as a kinetic pump. In these pumps, the added energy is still velocity and kinetic, but they use other effects than centrifugal pumps.
These pumps have the following major types:
1) Electromagnetic Pump
These types of pumps are used to move fluids such as brines, molten salts, liquid metals, or other conductive liquids using electromagnetic power.
In this type, the magnetic field is perpendicular to the direction of movement of the liquid and to the current flow. This creates an electromagnetic force that propels the fluid forward.
This type of pump is usually used to transfer liquid metal through cooling systems. They can also be found in many wave soldering devices that utilize an electromagnetic pump to circulate molten solder.
2) Jet Pump
The jet pumps are employed to force the fluids through a working nozzle, which transforms the pressure of the fluid into a high-velocity jet.
For the efficient working of the jet pump, you need to fill it completely with water. When the system starts, the water is expelled by using a centrifugal pump.
As the water enters the nozzle, it is forced through the venturi by creating a vacuum. When the water flows from the venturi to the section line, it moves with a greater pressure which causes to force the water back into the impeller.
How can we identify, Pump is pumping or not?
There are many factors through that we can identify that either our Pump is pumping or not. Some of them are given below in detail.
- If you are suspected that there is a problem with the pump, then lightly touch it. If it is working normally, it vibrates slightly, and you will feel it warm. If the Pump is not making a vibration and it’s not warm, then turn it off and open it with the help of a screwdriver to examine the problem.
- If water comes back from the Pump after switching it off, it may be because the one-way valve is not closed. This is another method to identify your hydro pump’s problems.
- If the water level does not change while the pump continues to run, the pump itself may be defective, the check valve may be stuck in the closed position, or the drain line may be blocked.
- Wear & Tear: No matter how robust the pumping system is, it will eventually suffer from wear and tear. How longstanding are your parts? If you have been using the pump for a long time, it may be essential to be exchanged. Check the system for any obvious signs of wear and tear, such as dirt or debris that has damaged the inside of the fitting, valve, hose, or pump.
Types of Pump Maintenance
The pump maintenance has the following types:
- Routine Maintenance
- Annual Maintenance
- Daily Maintenance
1) Routine Maintenance
Routine maintenance of the pumps includes the inspection of the following parts:
i) Bearing And Lubricant Condition
Daily monitor and record bearing temperature, lubricant levels, and vibrations. The lubricant must be clear and without foaming.
If there are air bubbles, it means that your bearing lubrication has a high temperature, and you must add more lubricant to lower the bearing temperature. If the bearing vibration increases, it may cause due to the failure of your bearing, and you must replace it immediately.
ii) Shaft Seal Condition
It would be best if you regularly inspected the mechanical seal of your pump. If there is any sign of leakage, it represents that your shaft seal has been leaked.
During the shutdown, check the packing of the pump to ensure proper lubrication. If the stuffing box packing appears dry and compressed, replace it and add lubricant according to the instruction manual.
iii) Overall Pump Vibration
An impending pump failure can detect via monitoring the entire pump vibration. Changes in pump alignment, bearing failure, cavitation, and blockages in the suction and discharge lines can cause excessive vibration.
iv) Pump Discharge Pressure
The total delivery pressure of the pump can be determined from the pressure difference on the inlet and outlet pressure gauges. Make sure the readings are within the pump’s design performance range. You can search it on the manufacturer’s website or in the operating instructions.
2) Annual Maintenance
Record the performance of the pump at least once a year. The benchmarking data should contain at least motor amp draw, flow rate, head pressure, and vibration for bearings.
Before the maintenance of your pump, you must disconnect the power source.
Following are major parts of the pump that you should inspect compulsory during the annual maintenance:
- Bearing Frame and Foot: Check the bearing frame for scale, rust, roughness, or cracks. The machined surface should have pitting or erosion.
- Bearing Frame: Check all tapped connections for contamination. Clean all the threads as essential. Eliminate all foreign or loose materials. Check the passages of the lubrication passages to ensure that they are free from any type of blockage.
- Shaft and Sleeve: Check the pitting or grooves. Inspect the shaft runout and sleeves, change the sleeve and shaft if worn or if the shaft has runout more than 0.002-inch.
- Casing: Check the pitting, corrosion, or wear symptoms of the casing. If the wear depth becomes more than 0125-inch, the casing must be replaced immediately. Inspect the surface of the gasket for distinctive signs.
- Impeller: Check the impeller of your pump for damage, corrosion, erosion, or wear. If the impeller blades have a bent shape or show wear of more than 0.125 inches, change your impeller as soon as possible.
- Frame Adapter: Check the frame adapter for signs of damage, corrosion, warping, or cracks. If your frame adaptor has these conditions, then replace it immediately.
- Bearing Casing: Check the cracks, corrosion, and wear signs on the casing of your pump bearings. If the bearing casing has any of these signs, replace it.
3) Daily Maintenance Checklist
- Daily inspect your pump for cavitation and noisy bearing problems.
- Inspect the gaskets and casing for pressure leakage.
- Check the glands and packing for any steam leaks. There should be no leakage of steam.
- Inspect the working of the heat tracing.
- Inspect the oil of the bearings for discoloration and water.
- Check the temperature of all bearings.
- Inspect the water-cooling system for efficient working. Check the temperature of the heat exchanger, jacket, and cooler by touching them.
- Check the oil ring and bearing via a filling port. Wash the covers of the bearings.
- Check the condition of the mechanical seal, it should be in normal condition.
- Inspect oil leakage at the gasket.
Applications of Pumps
- These use to transmit water from one place to another place.
- They use for fuel injection in different vehicles.
- Uses for cooling water purposes.
- For pumping gas or oil.
- It uses in the paper industry.
- Uses in the chemical industry.
FAQ Section
What is the function of pump?
A pump uses to transfer the fluids from one location to other. It just produces the fluid flow; it doesn’t produce pressure. A pump just generates the necessary fluid flow to develop the pressure, which helps the pump transfer fluid from one location to another.
What are the types of pumps?
The pumps have the following different types:
- Reciprocating Pumps
- Piston Pumps
- Plunger Pumps
- Centrifugal Pumps
- Rotary Pumps
- Submersible Pumps
- Axial flow Pumps
- Self-Priming Pumps
- Rotary lobe pumps
- Horizontal Pumps
- Vertical Pumps
- Jet Pumps
- Electromagnetic Pumps
Why do water pumps fail?
A water pump fails because of an imbalanced pump shaft or erosion inside the cooling system. But in maximum cases, water pumps are damaged due to the leakage of the shaft.
What are the two main types of pumps?
A pump has two main types:
What is a pump used for?
The pump mainly uses for pumping water, slurries, food, wastewater, oil, and gas. The pumps are also used for irrigation systems, power plants, wastewater treatment systems, chemical industries, food industries, fertilizer industries, etc.
Do pumps create pressure?
A pump can’t create pressure; it just generates the flow of fluid.
What are the Symptoms of Water Pump Failure?
Early identification of the problems is one of the best ways to troubleshoot and avoid pump failure. When the water pump goes bad, it generates one of the below-given symptoms:
- Leaks: Inspect the pump and pipes to identify the leakage that needs to be fixed. Because leakage can cause poor performance and loss of pump performance, frequent leaks come from mechanical seals or stuffing box packings. A mechanical seal is a wearing component, and it must be replaced regularly.
- Abnormal noise: The very first sign of a pump problem is abnormal noise. It is normal when the pump is running in normal condition. However, unusually loud or screeching noises can specify problems such as bearing wear.
- Excessive vibration: A properly installed and well-functioning pump doesn’t vibrate excessively. So, if it is vibrating excessively, you must immediately investigate the reason for the vibration. In maximum cases, the pump vibrates due to misalignment, damage, impeller imbalance, or misalignment of the electric motor.
- Corrosion: Discoloration, cracks, or rust of the pump housing or piping are symptoms of corrosion and should be removed instantly. Corrosion is a process that leads to pump failure by damaging the housing and other parts and also contaminates the pumping fluids.
- Overheating: Very high temperature of the bearings, motor, or pump always indicates a problem and should not be ignored. When you detect this problem, then you immediately investigate the problem and resolve it.
- Clogging: If the pump cannot handle the solid particles, it passes through the clogging problem. The presence of solid matter can clog the impeller or valve.
In this article, we deeply take a look at different types of pumps. So, I try my best to explain everything related to this topic. But if you need any more clarification then feel free and let me know your question in the comment section. I will try my best to clear you.