Positive Displacement Pumps: The Ideal Solution for High-Viscosity Fluids

When it comes to fluid handling systems, positive displacement pumps are indispensable in many industries, especially when dealing with high-viscosity fluids. These pumps offer unparalleled precision and reliability, making them ideal for applications that require consistent fluid flow, even under varying pressures.

Let's explore the ins and outs of positive displacement pumps.

⚡ What are they,

⚡ how do they work,

⚡ what types are available,

⚡ and why are they the preferred choice for handling thick and viscous fluids?

What are positive displacement pumps?

A positive displacement pump is a type of pump that moves a fixed amount of fluid with each cycle. Unlike centrifugal pumps, which rely on the conversion of kinetic energy into pressure to push fluid, positive displacement pumps operate on the principle of moving a set volume of fluid regardless of the system’s pressure. The core function of these pumps is to ensure that the flow remains constant and continuous, by using charge pumps to prevent cavitation, which is especially critical when handling high-viscosity fluids like oils, slurries, or thick chemicals.

The key advantage of positive displacement pumps is their ability to handle fluids that may be too thick or dense for centrifugal pumps. They offer precise control over flow, making them ideal for applications that demand accuracy and consistency.

How do positive displacement pumps work?

The mechanism of a positive displacement pump revolves around trapping a fixed volume of fluid and forcing it out with each stroke or rotation. This is achieved through the displacement of a chamber, either by moving a piston, diaphragm, or rotary element. In all of these pump designs, gaskets are used to create a tight seal around the moving parts, ensuring optimal performance and preventing fluid leakage. Whether you’re working with gear pumps, diaphragm pumps, or piston pumps, the right gasket material is essential to maintaining system integrity.

Rotary Pumps

These pumps use a rotating element to trap and move fluid. Common designs include gear pumps, screw pumps, and diaphragm pumps, all of which can efficiently transfer high-viscosity fluids.

Reciprocating Pumps

These pumps, such as piston and plunger pumps, use a back-and-forth motion to push fluid through the system. They are commonly used in applications requiring high pressures.

In both cases, the volume of fluid displaced remains constant, regardless of changes in the system’s pressure, which makes them well-suited for handling high-viscosity fluids and demanding industrial applications.

What are the different types of positive displacement pumps?

There are several types of positive displacement pumps, each designed to handle different applications and fluid types:

Diaphragm Pumps

These pumps use a flexible diaphragm to move fluids. They are ideal for hazardous, abrasive, or corrosive fluids and offer excellent control over flow.

Gear Pumps

Gear pumps, including external and internal gear pumps, are widely used for transferring high-viscosity fluids like oils, lubricants, and chemicals. They are reliable and provide steady, continuous flow.

Piston/ Plunger Pumps

These pumps use a piston to move fluid and are known for their ability to handle high-pressure applications. They are commonly used in oilfield services, well drilling, and high-pressure cleaning.

Screw Pumps

These pumps utilize a screw mechanism to move fluid and are often used in medium to high-viscosity applications. They are versatile and can handle a variety of fluids, including slurries and thick chemicals.

What are the key advantages of positive displacement pumps?

Positive displacement pumps offer several key advantages that make them ideal for handling high-viscosity fluids:

• Precise Flow Control: They deliver a constant and accurate flow regardless of pressure variations, making them ideal for applications where flow consistency is critical.

• High Efficiency with Viscous Fluids: Unlike centrifugal pumps, positive displacement pumps are highly efficient in handling high-viscosity fluids such as oils, slurries, and thick chemicals.

• High Pressure Capabilities: Positive displacement pumps can operate effectively under high pressure, making them ideal for industries like oil & gas and chemical processing that require reliable, high-pressure fluid transport.

• Versatility: These pumps can handle a wide range of fluids, including thin and thick liquids, chemicals, slurries, and hazardous materials, making them highly versatile across various industries.

What are the common applications of 

positive displacement pumps?

Positive displacement pumps are used in many industries due to their ability to handle a wide variety of fluids, including high-viscosity substances. Some common applications include:

Oil & Gas

Moving viscous oils, chemicals, and fluids in drilling and production operations, including mud pumps and water injection systems.

Chemical Processing

Transporting a wide range of chemicals, including aggressive, toxic, or high-viscosity substances before storing liquids or gases.

Food & Beverage

Moving viscous liquids like syrups, oils, and sauces without compromising consistency or quality.

Pharmaceuticals

Handling sensitive liquids such as active pharmaceutical ingredients, where precise flow and hygiene are paramount.

Water Treatment

Transporting chemicals for treatment, filtration, and other processes that require precise control over flow.

What should you consider when making a positive displacement pump selection?

Choosing the right positive displacement pump for your application involves several key factors:

Fluid Viscosity

Select a pump designed to handle the thickness of the fluid being pumped. Higher viscosity fluids require more robust pumps like gear or diaphragm pumps.

Pressure Requirements

Determine the maximum pressure your application will require. Some pumps, like plunger pumps, are better suited for high-pressure environments.

Flow Rate

Ensure that the pump delivers the correct flow rate for your system’s needs. Positive displacement pumps are excellent for constant, reliable flow but need to match the system’s requirements.

Material Compatibility

Choose a pump that is compatible with the fluid’s chemical properties to prevent damage from corrosion or wear.

What are some maintenance and troubleshooting tips for positive displacement

pumps?

To keep positive displacement pumps running efficiently, regular maintenance is necessary:

• Routine Maintenance: Regularly inspect seals, replace worn parts, and ensure proper lubrication to extend pump life.

• Common Issues: Look out for leaks, wear on seals, or decreased performance due to blockages or improper pressure.

• How to Extend Pump Life: Clean the pump regularly, monitor fluid quality, and replace damaged parts promptly to prevent costly repairs or downtime.

What does the future of fluid handling hold for positive displacement pumps?

The future of positive displacement pumps lies in efficiency and automation. Advances in smart technology and IoT allow for real-time monitoring of pump performance, optimizing efficiency and reducing maintenance costs (see IoT for industrial automation) - ask a pump expert! With increasing pressure for energy-efficient solutions, future pumps will focus on reducing power consumption while increasing durability, making them ideal for high-demand industries like oil & gas, water treatment, and food processing.

Do you need custom pump solutions for your project?

Whether you’re handling slurries, oils, or chemicals, understanding how to choose the right positive displacement pump can significantly improve efficiency and performance in your systems. For expert guidance on selecting the right positive displacement pump for your application, contact EV Pump & Equipment today. Our team of professionals can help you find the most efficient, cost-effective solution to meet your needs.

EV Pump & Equipment is a leading provider of high-performance fluid handling solutions, specializing in custom pump systems and comprehensive services for industries like oil & gas, petrochemical, and municipal water. With a deep passion for pumps and a commitment to excellence, we deliver reliable, efficient solutions tailored to meet the unique needs of every client. Our hands-on approach and elite equipment ensure that your operations run smoothly and efficiently, every time.