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How do piston pumps work?

An explanation of the operating principle of these mechanical devices


How do piston pumps work?

Piston pumps are one of the key components in fluid transfer and circulation systems for a wide range of industrial and engineering applications. Their efficiency and versatility make them a common choice in sectors such as the chemical industry, mechanical engineering, and the oil industry. 

With this article, we will try to provide an in-depth analysis of the operation of piston pumps, exploring the various phases that regulate their functioning.

The basic operating principle

As mentioned earlier, piston pumps are devices designed to generate a constant flow of a liquid, through the reciprocating movement of one or more pistons within a cylinder. This reciprocating movement is the result of the application of an external mechanical force, often generated by an electric motor or an internal combustion engine.

Piston pumps operate following three fundamental phases:

  • suction;
  • compression;
  • discharge. 

Let's examine each phase in detail:

Suction Phase

The suction phase is the first essential step in the operation of a piston pump. During this phase, the piston moves backward within the cylinder, moving away from the suction chamber. This piston movement creates a void inside the cylinder, reducing the pressure within it. This pressure reduction leads to the creation of a relative negative pressure, which is lower than that of the surrounding environment.

This negative pressure is what allows the liquid to be sucked from the feed pipe into the pump's suction chamber. In other words, the higher pressure in the surrounding environment pushes the fluid into the cylinder through the suction valves, utilizing the fundamental principle of flow from higher pressure points to lower pressure ones.

The effectiveness of the suction phase depends on several factors, including the power of the engine pushing the piston backward and the presence of well-designed suction valves that allow efficient fluid flow.

Compression Phase

The compression phase is the second crucial step in the operation of piston pumps. Once the liquid has been successfully sucked into the suction chamber, the piston begins its forward movement within the cylinder. This movement into the cylinder is the result of the energy provided by the engine or the power source associated with the pump.

As the piston moves forward, the fluid inside the cylinder is compressed. This means that the volume occupied by the fluid is reduced, generating an increase in pressure. The amount of pressure generated in this phase depends on several factors, including the power of the engine powering the pump, the speed of the piston, and the pump's specific configuration, such as the cylinder diameter and compression ratio.

Therefore, the ability to generate adequate pressure during this phase is closely linked to the overall power and efficiency of the piston pump.

It's also important to note that piston pumps can be designed to operate at different compression pressures, depending on the specific needs of the application.

Discharge Phase

The discharge phase is the third and final step in the operating cycle of piston pumps. During this phase, the piston continues its forward movement within the cylinder and pushes the compressed liquid through a discharge pipe. It's important to highlight that the pressure generated during the compression phase is crucial for the success of the discharge phase.

The pressure accumulated in the fluid during the compression phase is sufficient to overcome any resistance present in the piping system. This resistance can come from the length of the pipes, the diameter of the ducts, or the presence of regulating valves. The pressure generated in the cylinder by the piston's compression provides the necessary energy to overcome these resistances and make the fluid flow in the desired direction.

The compressed fluid, now at high pressure, can be directed to the desired destination point, where it will perform its specific task in the industrial application.

This final phase shows us how the careful design of the discharge pipes, pressure management, and flow control are essential to ensure the efficient and safe operation of piston pumps.

Conclusion and the role of Emiltec

Understanding the operating principle of piston pumps is essential to ensure the correct functioning of industrial processes and optimize the efficiency of fluid transfer systems. In this landscape, we at Emiltec position ourselves as a reliable supplier of water piston pumps for numerous industrial processes

Moreover, our extensive experience in the field allows us to collaborate side by side with our customers to fully understand their specific needs, the operating environment, and the challenges they face. This deep understanding allows us to provide highly personalized consulting and support services, aimed at optimally meeting any need.

Get in contact with us now!