Positive Displacement Pump

Positive Displacement Pump (PDP), also known as PD Pump, is a versatile and efficient pumping solution widely used in various industries. On this page, you will discover everything you need to know about positive displacement pumps - their advantages, working principles, and the different types available. Rely on Fluid-o-Tech and discover more!

On this page, you discover:

What is a positive displacement pump?

How a PDP pump works

The advantages of a PD pump

Which are the positive displacement pump types?

Fluid-o-Tech's Positive Displacement Pumps

What is a Positive Displacement Pump?

A positive displacement pump, also known as a volumetric pump, moves fluid by trapping a fixed amount of it and displacing it into the pump's discharge pipe.

Unlike centrifugal pumps, which rely on impellers to generate flow, PD pumps use mechanical means to move the fluid. This design ensures a consistent flow rate with low pulsations.

How a PD Pump Works

Positive displacement pumps operate based on the principle of creating and maintaining a fixed volume within the pump. Here's a simplified working process:

• The pump's rotating or reciprocating mechanism creates a pressure differential

• This pressure difference opens the inlet valve, allowing fluid to enter the pump chamber

• As the rotating or reciprocating mechanism moves, the fluid is trapped within the chamber and transported to the discharge side

• The outlet valve opens, and the fluid is expelled into the discharge pipe

• The process repeats, maintaining a continuous flow of fluid.

The Advantages of a PD Pump

A PD Pump offers a wide range of advantages that make it a preferred choice in various industries. Here are some of its best qualities:

Precise Flow Control - positive displacement pumps deliver a constant flow rate, making them ideal for applications requiring accurate dosing and metering

High-Pressure Capability - PD pumps can generate high discharge pressures, enabling them to handle challenging tasks like pumping viscous liquids or overcoming system resistance

Self-Priming - these pumps can self-prime, meaning they can draw fluid into the pump without the need for additional priming mechanisms

Versatility - Positive displacement pumps can handle a wide range of fluids, including corrosive, abrasive, or high-viscosity liquids

Efficiency - PD pumps have high overall efficiency, ensuring minimal energy waste during operation.

Are you interested in a positive displacement pump for your production process? Fluid-o-Tech is here for you!

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What are the Positive Displacement Pump Types?

First of all, it is important to know that, within the realm of positive displacement pumps, there exist two primary classifications: reciprocating and rotary displacement pumps

Reciprocating displacement pumps

A reciprocating displacement pump is a positive displacement pump that uses reciprocating motion, typically driven by a piston or plunger, to create pressure and displace fluid. The pump's reciprocating action draws in fluid through an inlet valve and then forces it out through a discharge valve in a repetitive back-and-forth motion.

Here are the specific pumps included in this category:

Diaphragm pumps - utilize a flexible diaphragm to displace and transfer fluids. It operates by cyclically flexing the diaphragm, creating suction and discharge strokes to move the fluid through the pump. The diaphragm acts as a barrier between the pumped fluid and the moving parts of the pump, providing a seal and preventing cross-contamination. These pumps are commonly used for applications that require gentle handling of fluids, as they can handle sensitive or abrasive liquids without damaging or contaminating them

Flexible Impeller - this special pd pump is commonly used for pumping fluids with low to moderate viscosity. It consists of a rotating impeller with flexible vanes or blades made of materials such as rubber or thermoplastic elastomer that allow the vanes to bend and flex. This flexibility creates a seal against the pump housing, effectively trapping and displacing the fluid. When the impeller rotates, the flexible vanes expand and contract, drawing in fluid through the inlet and propelling it out through the outlet. This mechanism ensures a consistent flow and gentle handling of the fluid

Peristaltic Pumps - operate by squeezing and releasing a flexible tube or hose to move fluids. It utilizes a rotating mechanism, typically consisting of rollers or lobes, to compress the tube, creating a series of isolated fluid pockets. As the mechanism rotates, the squeezed section of the tube moves along, pushing the fluid in the desired direction. This technology enables the continuous pumping of fluids without interruptions and with complete isolation between the pump and the fluid, eliminating any direct contact.

Rotary displacement pumps

A rotary displacement pump is a PDP pump that utilizes a rotating mechanism, such as gears, lobes, or screws, to generate pressure and transport fluid. The rotating action of the pump creates chambers that trap and transport fluid from the inlet to the outlet, ensuring a consistent flow rate and precise fluid displacement.

This category includes four specific pumps:

Rotary lobe pumps - consist of rotating lobes within a pump casing. The lobes create chambers that draw in fluid through an inlet port and push it out through a discharge port. The design of this pd pump ensures a steady flow without pulsations. The fixed clearance between the lobes and casing allows efficient fluid transfer without causing shear or damage, making it ideal for viscous and shear-sensitive liquids such as food products, slurries, and industrial fluids

Screw pumps - are a type of positive displacement pump that utilizes an intermeshing screw and casing to transfer fluid. It operates by the rotational motion of the screw, which creates a sealed chamber between the screw threads and the pump casing. As the screw rotates, the fluid is trapped and carried along the length of the screw threads, ultimately being displaced from the inlet to the outlet of the pump

Gear Pumps - are a type of positive displacement pump that uses meshing gears to transfer fluids. It consists of two interlocking gears, typically spur gears or helical gears, housed within a pump casing. As the gears rotate, fluid is trapped within the spaces between the gear teeth and the pump casing, creating a continuous flow. The operation of a gear pump relies on the principle of positive displacement, where a fixed volume of fluid is transferred with each revolution of the gears. This results in a steady and consistent flow rate, making gear pumps suitable for applications that require precise fluid delivery and dosing accuracy

Rotary Vane Pumps - utilize rotating vanes or blades to create suction and generate fluid flow. They consist of a cylindrical rotor with multiple vanes inserted into radial slots. As the rotor rotates, the vanes slide in and out due to centrifugal force and contact with the pump casing. During the intake stage, the rotating vanes create expanding volumes that draw in fluid through the inlet. As the rotor continues to rotate, the vanes push the fluid toward the outlet, compressing it and generating pressure. Finally, the fluid is then discharged from the pump.

Fluid-o-Tech's Positive Displacement Pumps

Are you looking for a reliable positive displacement pump manufacturer?

Fluid-o-Tech offers a wide range of reliable and efficient positive displacement pumps for various industrial applications. With our expertise in pump manufacturing and dedication to quality, our PD pumps deliver exceptional performance, durability, and precision in fluid transfer processes.

As a manufacturer of PD pumps, our offerings extend beyond off-the-shelf products. We provide an effective and high-quality customization service tailored to fulfill our customers' specific requirements.

First of all, we provide a technical blueprint outlining the structure and functionality of your PD pump. This blueprint adheres to the most rigorous standards and addresses our customers' exacting demands. Throughout the design phase, we meticulously select the most appropriate materials, resilient components, and cutting-edge technology.

Take the next step into the world of positive displacement pumps with Fluid-o-Tech!

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