are very important part of the ship’s machinery and any other industry which is present in the world. High pressure is the main characters of this pump, and this high pressure output are being used in places like starting of the engine or you can say the building of pressure in the fluids. But there are used in limited application because they require lots of maintenance. There are several reciprocating pump pdf
books available in market. These pumps are positive displacement pumps
and that is the reason they do not require any type of priming for their functioning in the starting period of the pump. So let’s discuss about this pump in much more detail.
Parts and design of the Reciprocating pump
Following are the parts of the centrifugal pump:
- A piston
- Inlet and outlet valve
- Relief valve
- Piston rings
These are some of the parts of the reciprocating pumps and this works same like an I.C engine but there is no combustion in this but the whole process is same as we have in the I.C engine.
Material Used in Making of the pump
Piston: Generally made of the mild steel
Liner: Made of Mild steel
Valves: There are also made of steel but a little improved form which has the stiffness and less wear and tear are used and brass can also
Working principle of the reciprocating pump
The working of the reciprocating pump is very simple and just like an I.C engine. First of all the piston has the function of providing the suction force, so that the liquid can be lifted up or can be sucked in with great force. After that comes the compression part which will impart the required pressure energy to the fluids. In this part of the phase the piston has to do a great work so that the liquid can be compressed properly and its pressure can increase to the desired level. The inlet and the outlet valve open at a certain pressure which is set by the manufacturer.
In the diagram above you can see that the piston is of a single acting type which means it can suck from one side and transmit to the same side only. But we can have the double reciprocating pump too which have the function of the giving suction and discharge simultaneously in each stroke. This pump can be used as the compressor also but for that we have to have a good valve arrangement which can operate with good frequency.
Note: It is to be noted that the reciprocating pump is a positive displacement pump which means that the fluid can only move in one direction and can never reverse back. So due to this the pump is always started with the outlet valve open otherwise the pressure will keep on building and this will lead to rupture of the pipeline or even the pump itself. But if relief valve is fitted then this pressure will come down.
Maintenances required on the reciprocating pump
There is no doubt that the reciprocating pump provides us the pressure as much as we want but since there are so many moving parts in this pump. So the wear and tear is a lot in this pump. So there are various maintenances which are done with this pump in order to keep it working and also for its long life. This is the reason why these pumps are limited in use and only used in places where there is high suction and high pressure head is required. Following are the maintenances which are carried on this pump:
- The piston rings which are used are always in direct contact with the liner body and hence they wear a lot, so we have to change them time to time.
- The valves used in this pump have to be taken care properly as it will lead leakage if they go bad, so they have to take care off while maintaining of the pump.
- The gland packing from where the shaft comes out of the pump has to be taken care in order to check its leakage.
- In coupling or the cross head of the pump by which the piston gets the liner motion also have to check for any type of misalignment and wear and tear.
Uses of reciprocating pump
There are various uses of the reciprocating pump and they are as follows:
- The lubricating pump is a reciprocating pump and it supplies the lubrication oil to the main engine. The main bilge suction pump is also a reciprocating pump.
- For ballast they are sometimes used.
Advantages of Reciprocating pump
Advantages of the reciprocating pump are as given below:
- Gives high pressure at the outlet.
- Gives high suction lift.
- Priming is not required in this pump.
- They are used for air also.
Disadvantages of Reciprocating pump
Disadvantages of the reciprocating pump are given below:
- High wear and tear, so requires a lot maintenance
- The flow is not uniform, so we have to fit a bottle at both ends.
- The flow is very less and cannot be used for high flow operations.
- More heavy and bulky in shape.
- The initial cost is much more in this pump.
There is no doubt that these pumps are best when it comes to providing us with high pressure. But as we have seen that there are lots of maintenance which are required in this pump. So we can say these pumps are used in places where there is a specific purpose for them to be used. So this was all about the reciprocating pump.