Something About Plunger Pump You Need to Know


What is Plunger Pump and Piston Pump? What’s the Difference Between Piston and Plunger Pumps?

Piston Pumps:

Piston pumps operate by using one or more pistons to displace fluid within a cylinder. These pistons move back and forth, drawing fluid into the cylinder on the intake stroke and forcing it out on the discharge stroke. The movement of the pistons creates pressure, which drives the fluid through the system. Piston pumps are known for their high efficiency and reliability, making them suitable for a wide range of applications, including automotive, construction, and manufacturing.

Plunger Pumps:

Plunger pumps, on the other hand, utilize one or more plungers to displace fluid. Unlike pistons, which have a circular cross-section, plungers have a cylindrical shape with a flat or slightly tapered end. Plunger pumps operate similarly to piston pumps, with the plungers moving back and forth within a cylinder to create pressure and move fluid through the system. Plunger pumps are often favored for their ability to handle high-pressure applications with precision and consistency, making them ideal for tasks such as high-pressure washing, water jet cutting, and oil and gas exploration.

Differences Between Piston Pumps and Plunger Pumps

Differences Between Piston Pumps and Plunger Pumps

Design: Piston pumps use pistons with circular cross-sections, while plunger pumps utilize cylindrical plungers with flat or tapered ends.

Pressure Handling: Plunger pumps are typically better suited for high-pressure applications compared to piston pumps. The design of the plungers allows for greater force to be exerted on the fluid, resulting in higher pressure output.

Precision: Plunger pumps offer greater precision and control over pressure and flow rates, making them ideal for applications that require accuracy and consistency.

Applications: While both piston and plunger pumps are used in a variety of industries, their specific applications may differ. Piston pumps are commonly found in hydraulic systems where moderate pressure and flow rates are required, while plunger pumps excel in high-pressure applications that demand precision and reliability.

How Does a Plunger Pump Work? What is a Plunger Pump Used for?

Components of a Plunger Pump

A typical plunger pump comprises several key components:

1. Plunger or Piston: The reciprocating component responsible for drawing in and pressurizing the fluid.


2. Cylinder: The housing where the plunger moves back and forth.

Plunger Pump Working


3. Valves: Inlet and outlet valves that regulate the flow of fluid into and out of the cylinder.


4. Seals and Packing: Ensure proper sealing to prevent fluid leakage.


5. Drive Mechanism: Power source (electric motor, engine, etc.) that drives the plunger’s movement.

How Does a Plunger Pump Work?

The operation of a plunger pump is relatively straightforward:

1. Suction Stroke: During this phase, the plunger moves backward, creating a vacuum that draws fluid into the cylinder through the inlet valve.


2. Compression Stroke: The plunger then moves forward, pressurizing the fluid within the cylinder.


3. Fluid Discharge: As the pressure exceeds that of the outlet valve, the fluid is expelled from the cylinder.

What is a Plunger Pump Used for?

Plunger pumps are used in industries such as construction, manufacturing, oil and gas, chemical processing, and power generation because of their ability to accurately and reliably handle high-pressure fluid systems. Common equipment includes pressure washing equipment used to clean surfaces such as vehicles, buildings, and industrial equipment, and hydrostatic testing equipment used to test pipes, containers, and industrial components.

Why is My Plunger Pump Not Working?

What causes hydraulic plunger pump failure? In daily use, several reasons may cause the plunger pump to malfunction, which require our attention:

Fluid Contamination: Contaminants such as dirt, debris, or air in the hydraulic fluid can cause abrasive wear, leading to pump component damage and reduced efficiency.

1. Overheating: Excessive heat can degrade the hydraulic fluid and damage pump components, leading to premature failure. Overheating can result from prolonged operation at high pressures or inadequate cooling.

2. Lubrication Issues: Insufficient lubrication of moving parts can cause friction and wear, leading to pump failure. This can occur due to improper maintenance, low-quality lubricants, or leaks in the system.

3. Cavitation: Cavitation occurs when the hydraulic fluid vaporizes due to low pressure at the pump inlet, leading to the formation of air bubbles. These bubbles implode when entering higher-pressure regions, causing damage to pump surfaces and reducing efficiency.

4. Excessive Pressure: Operating the pump beyond its rated pressure limits can cause stress on pump components, leading to deformation, cracking, or seal failure.

5. Improper Installation or Maintenance: Incorrect installation, inadequate maintenance practices, or neglecting to replace worn components can contribute to pump failure over time.

6. Material Fatigue: Continuous cyclic loading or exposure to high-stress conditions can lead to fatigue failure of pump components, such as plungers, pistons, or valve plates.

7. Seal Failure: Seals and gaskets play a crucial role in preventing fluid leakage and maintaining hydraulic system integrity. Seal failure due to wear, damage, or improper installation can result in fluid leakage and pump inefficiency.

To diagnose and resolve the issue, it’s essential to inspect the pump system thoroughly, check for any visible damage or obstructions, ensure proper fluid levels and quality, and address any underlying mechanical or electrical issues. If necessary, consult a qualified technician for further troubleshooting and repair.

How Much Does a Plunger Pump Cost?

The cost of a plunger pump can vary depending on several factors such as brand, specifications, capacity, and features. Generally, plunger pumps can range in price from a few hundred dollars to several thousand dollars. Basic models intended for residential or light commercial use may be more affordable, while heavy-duty industrial-grade pumps with higher capacity and advanced features can be more expensive. Additionally, factors such as maintenance requirements, warranty coverage, and aftermarket support may also influence the overall cost. It’s essential to consider your specific application needs and budget when selecting a plunger pump.

Plunger Pump in excavator


1. Q: How do I troubleshoot a leaking plunger pump?

A: Before troubleshooting a leaking piston pump, make sure the pump has sufficient hydraulic oil to ensure that air does not enter the system and cause leaks during the test. First, the plunger pump is pressure tested to determine the area where liquid escapes. Secondly, check the appearance of the pump, the wear of seals and gaskets, the tightness of connections and fastening parts, whether there are cracks in the high-pressure hose, and whether the pump valve and pump piston are operating normally.
Finally, if you are unable to identify or correct the problem on your own, consider seeking help from a qualified technician or pump repair specialist.

2. Q: What are the common causes of cavitation in plunger pumps?

A: Common causes of cavitation in plunger pumps include inadequate inlet pressure, blockages or restrictions in the inlet lines, improper suction line size, excessive pump speed, air leakage, high fluid temperature, improper pump installation, inadequate fluid viscosity, pump wear or damage, and operating conditions outside the pump’s specified range. Cavitation occurs when low-pressure areas form in the fluid due to rapid pressure changes, leading to the formation of vapor bubbles. These bubbles collapse violently when they enter high-pressure regions, causing damage to pump components and reducing efficiency. To prevent cavitation, operators should ensure sufficient inlet pressure, maintain clear and unrestricted inlet lines, use proper suction line sizes, operate the pump within recommended speed ranges, address air leaks, monitor fluid temperature, follow correct installation procedures, use fluids with suitable viscosity, perform regular maintenance to address wear or damage, and operate the pump within specified conditions.

3. Q: Can I replace the plunger pump seals myself, or should I seek professional assistance?

A: The answer to this question is no. Replacing a plunger pump seal is a very precise matter. Professional technicians have the specialized tools, knowledge and skills to perform tasks efficiently, minimizing the risk of errors or pump damage. Additionally, a professional can inspect the pump for any potential issues that could cause the seal to fail and address them appropriately. This helps prevent future seal failures and ensures optimal pump performance.

4. Q: How often should I lubricate my plunger pump?

A: How often you lubricate a piston pump depends on a variety of factors, including the pump’s operating conditions, intensity of use, and manufacturer’s recommendations. Typically, plunger pump oil should be changed every 3 months or 500 hours. As operating time and temperature increase, additional lubrication may be required to ensure smooth operation and extend its service life. It is recommended to refer to the pump’s owner’s manual or manufacturer’s guidance for specific lubrication intervals and recommendations.

5. Q: Is it possible to upgrade an existing plunger pump to increase its pressure output?

A: Yes, it is possible to upgrade an existing plunger pump to increase its pressure output. This can be achieved through various methods, such as replacing the pump’s components with higher-pressure-rated parts, adjusting the pump’s settings or parameters, or installing additional equipment like booster pumps or pressure intensifiers. However, it’s essential to consult with a professional or the pump manufacturer to ensure that the upgrade is compatible with the pump’s design and specifications. Additionally, proper installation and calibration are crucial to maintain the pump’s reliability and safety.

0 replies

Leave a Reply

Want to join the discussion?
Feel free to contribute!

Leave a Reply

Your email address will not be published. Required fields are marked *