In this article, we will learn the definition, parts, working principle, advantages, types, and disadvantages of Reciprocating Pumps. We have also provided a PDF download link for the same. Reciprocating Pump is a positive displacement type pump.
Definition of a Reciprocating Pump
A reciprocating pump is a hydraulic machine that converts mechanical energy into hydraulic energy. Here a certain volume of liquid is collected in the enclosed volume and is discharged using pressure to the required application. Reciprocating pumps are more suitable for low volumes of flow at high pressures.
Main Parts or Components Reciprocating Pump with their Function
A reciprocating pump consists of the following parts which are as follows
- Suction Pipe
- Suction Valve
- Delivery Pipe
- Delivery Valve
- Cylinder
- Piston and Piston Rod
- Crank and Connecting Rod
- Strainer
- Air Vessel
the Schematic Diagram of a Reciprocating Pump
Suction Pipe
- Suction Pipe is used to suck the water from the water reservoir to the cylinder.
- It connects the inlet of the pump with the water tank.
Suction Valve
- The suction valve is a non-return valve which means only one-directional flow is possible in this type of valve.
- This is placed between the suction pipe inlet and the cylinder.
- During suction of liquid, it is opened and during discharge, it is closed.
Delivery Pipe
- A delivery pipe is a pipe that is used to deliver the water from the cylinder to the desired location.
- It connects the outlet of the pump to the tank where the water is to be delivered.
Delivery Valve
- Delivery valve is also a non-return valve placed between the cylinder and the delivery pipe outlet.
- It is in a closed position during suction and in opened position during discharging of liquid.
Cylinder
- A hollow cylinder made of steel alloy or cast iron.
- An arrangement of pistons and piston rods is inside this cylinder.
Piston and Piston Rod
- A piston is a solid type cylinder part that moves backward and forwards inside the hollow cylinder, to perform suction and delivery of liquid.
- The piston rod helps the piston to its linear motion.
Crank and Connecting Rod
- A crank is a solid circular disk which is connected to a power source like a motor, engine, etc. for its rotation.
- Connecting rod connects the crank to the piston, as a result, the rotational motion of the crank gets converted into the linear motion of the piston.
Strainer
- A strainer is provided at the end of the suction pipe to prevent the entrance of the solids particle from a water source into the cylinder. Otherwise, solid particles choked the delivery.
Air Vessel
- Air vessels are connected to both suction and delivery pipes to eliminate the frictional head and to give a uniform discharge rate.
Working Principle of a Reciprocating Pump With Diagram
This type of pump consists of a piston that moves forward and backward in a close-fitting cylinder. The movement of the piston is obtained by connecting the piston rod to the crank using a connecting rod. The crank is rotated using an electric motor.
Suction and Delivery Pipes with a suction valve and a delivery valve are connected to the cylinder. The suction and delivery valves are nonreturn valves, which allow the water to flow in one direction only. The suction valve allows water from the suction pipe to the cylinder and whereas the delivery valve allows water from the cylinder to the delivery pipe only.
From the above diagram, When a crank is at A, the piston is at the extreme left position in the cylinder. As the crank is rotating from A to C,(θ=0º to 180º) the piston is moving towards the right in the cylinder. The movement of the piston towards the right creates a partial vacuum in the cylinder. But on the surface of the liquid in the sump atmospheric pressure is acting, which is more than the pressure inside the cylinder.
Thus the liquid is forced into the suction pipe from the sump. This liquid opens the suction valve and enters the cylinder. When a crank is rotating from C to A (θ=180º to 360º), the piston from the extreme right position starts moving toward the left in the cylinder.
The movement of the piston towards the left increases the pressure of the liquid inside the cylinder more than the atmospheric pressure. Hence the Suction valve closes and the delivery valve opens. The liquid is forced into the delivery pipe and is raised to a Required Height.
Reciprocating pump Types
A Reciprocating Pump can be categorized into three Types which are as follows
According to Mechanism
- Single-acting
- Double-acting Reciprocating Pump
According to Air vessel
- Pump with air vessel and
- Pump without air vessel.
According to Number of cylinders
- Single cylinder
- Double cylinder and
- Triple cylinder pump.
Single-acting Reciprocating pump
The name itself is “single” which means there is only one suction and deliver valve, suction, and delivery pipe. The fluid sucks only in one direction which is suction stroke and it delivers that is called deliver stroke.
Double-acting Reciprocating Pump
Here It has two suction and delivers valve, suction, and delivery pipe. Consider, when the piston in a cylinder is in between then one suction and a delivery pipe is on one side(Piston left) and one pipe at another side (piston right).
Pump with air vessel
It means a continuous flow of water at a uniform rate. It accumulates water by compressing air in the vessel.
Pump without air vessel
A pump without an air vessel means there is some amount of air present in the water. As per the work requirement at the domestic place, these types of pumps are used.
Single Cylinder
Here only one cylinder is connected to a shaft.
Double cylinder
There is a two-cylinder attached to a single shaft. The main difference from the single-cylinder pump is here there is separate suction and the delivery valve is provided to each cylinder.
Triple cylinder
In this pump, there is a three-cylinder connected to it.
Reciprocating Pump Application
- Oil drilling operations.
- Pneumatic pressure systems.
- Light oil pumping.
- Feeding small boilers condensate return, etc.
Reciprocating Pump Advantages
- High pressure is obtained at the outlet.
- The priming process is not needed in this pump.
- Reciprocating Pump provides high suction lift.
- It is also used for air.
Reciprocating Pump Disadvantages
- It requires high maintenance, because of more wear and tear of the parts.
- Low flow rate (it discharges a low amount of water).
- They are heavy and bulky in size.
- The initial cost is High.
FAQ
What Are The Types Of Reciprocating Pump?
According to Mechanism
- Single-acting
- Double-acting Reciprocating Pump
According to air vessel
- Pump with air vessel and
- Pump without air vessel.
According to Number of cylinders
- Single cylinder
- Double cylinder and
- Triple cylinder pump.
What are the advantages of the reciprocating pump?
- High pressure is obtained at the outlet.
- The priming process is not needed in this pump.
- Reciprocating Pump provides a high suction lift.
- It is also used for air.
Conclusion
In conclusion, reciprocating pumps are positive displacement pumps that use a reciprocating motion to move fluids. They consist of various parts such as a piston, cylinder, suction and delivery valves, and power source. The working principle of reciprocating pumps involves the movement of a piston or plunger, which creates a pressure difference that forces the fluid to flow. There are seven types of reciprocating pumps, including piston pumps, plunger pumps, diaphragm pumps, metering pumps, hydraulic pumps, steam pumps, and air-operated pumps. Each type has its advantages and limitations, making them suitable for different applications.
Overall, reciprocating pumps are widely used in various industries due to their high efficiency, versatility, and ability to handle viscous fluids. However, they require regular maintenance and may suffer from issues such as leakage, cavitation, and mechanical wear. Therefore, proper selection, installation, and maintenance of reciprocating pumps are crucial to ensuring their reliable operation and longevity.
References
More resources
- Difference between pump and compressor
- Pump
- Thermodyanmic Systems
- Stress and Strain curve
- Stress Concentration
- Difference between centrifugal pump and reciprocating pump
