Positive Displacement Pump

What Is a Positive Displacement Pump?

A Positive Displacement Pump (PDP) is a type of pump that moves fluid by trapping a fixed amount and forcing (displacing) that volume into a discharge pipe. Unlike centrifugal pumps that rely on velocity and kinetic energy, PDPs deliver a steady, consistent flow—no matter the system pressure.

In fluid handling systems, PDPs are essential for precise dosing, metering, and transferring thick, abrasive, or high-viscosity fluids. From chemical manufacturing to oil and gas operations, PDPs are used wherever reliable, pressure-driven flow is critical.

Whether you’re moving sludge in wastewater treatment or feeding additives in an oilfield operation, PDPs offer durability, efficiency, and control.

How Does a Positive Displacement Pump Work?

Positive Displacement Pumps work by physically enclosing a volume of fluid, then moving it through the system. The core principle: trap and displace.

Unlike kinetic pumps (like centrifugal), PDPs don’t rely on high-speed rotation to generate flow. Instead, they use mechanical motion—like pistons or rotating gears—to push fluid at a constant rate.

This makes them ideal for systems where:

• Pressure needs to remain high

• Flow must be accurate and repeatable

• Fluids are thick, gritty, or corrosive

They’re especially useful for fluid processing systems where flow precision matters more than sheer volume.

Types of Positive Displacement Pumps

There are two main categories of PDPs: reciprocating and rotary.

Reciprocating Pumps

• Piston Pumps: Ideal for high-pressure systems like hydraulic applications.

• Diaphragm Pumps: Excellent for chemical transfer and dry-run capability.

Rotary Pumps

• Gear Pumps: Compact and robust, used in lubrication or fuel systems.

• Vane Pumps: Deliver smooth flow with low pulsation—common in automotive and aerospace.

• Lobe Pumps: Sanitary and gentle, used in food, beverage, and pharmaceutical processing.

• Peristaltic Pumps: Use rotating rollers and tubing, perfect for metering and dosing.

Want a deeper dive? Check out how Grinder Pumps and Diaphragm Pumps fit into our full pump systems lineup.

Common Applications & Industries

Positive Displacement Pumps are found in industries where precision and reliability are critical:

• Oil & Gas: Chemical injection, additive feeding, well servicing

• Chemical Processing: Corrosive and abrasive fluid handling

• Food & Beverage: Sanitary transfer of viscous ingredients

• Wastewater & Mining: Sludge, slurry, and abrasive media

• Agriculture: Fertilizer dosing, irrigation systems

PDPs work seamlessly alongside:

• Mud Pumps

• Trash Pumps

• Surface Pumps

• Charge Pumps

…as part of complete fluid handling equipment systems.

Positive Displacement Pumps in Field Operations

In real-world environments, PDPs stand up to demanding field conditions:

• Horizontal Directional Drilling (HDD): Transfer of drilling slurries and lubricants

• Well Pump Replacement: Ideal for isolated, remote, or sludge-heavy systems

• Temporary Bypass Systems: Reliable flow in emergency or backup configurations

• Sludge and Slurry Handling: Move abrasive and solid-laden fluids without clogging

Whether paired with grinder pumps or diaphragm pumps, PDPs are essential to rugged, mobile fluid handling.