Peristatic pumps: Technical Overview

This guide aims to describe the main technical features of peristaltic pumps, explain how they work, the advantages and disadvantages of this technology, and where they are most commonly used. Finally, we will make a brief mention of Fluid-o-Tech peristaltic pumps.

The following are the specific points we will cover:

• What is a peristaltic pump?

• How does a peristaltic pump work?

• Main fields of application

• Advantages & disadvantages

• Fluid-o-Tech peristaltic pumps

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What is a peristaltic pump?

A peristaltic pump is part of the world of positive-displacement pumps, i.e. all those types of pumps that exploit the volume variation in a pump chamber to move and pressurize a fluid. In positive-displacement pumps, the flow rate is always directly proportional to the speed.

The structure of the pump is free from valves, seals, and glands, thus offering an improved design and easier maintenance. They are suitable for different flow ranges and liquid types.

This technology, regardless of size, is able to continuously pump the fluid without interruptions and without coming into contact with it, creating perfect isolation between the fluid and the pump.

Because of its nature, the peristaltic pumps can produce pulsations. This happens when the flow rate is not constant. Usually, a higher number of rollers can reduce the flow rate thus limiting pulsation.

How does a peristaltic pump work?

Principle of operation of peristaltic pumps: peristaltic pumps use the principle of peristalsis, whereby the alternating deformation and compression of a soft hose transports the fluid. This is done by means of a rotating roller that deforms the hose:

• the pump is made of a rotor presenting one or more rotating rollers on its circumference that occlude an elastic hose (made of silicone, PVC, or other polymers)

• the hose can also be compatible with solvents, inks and paints, and other types of fluids

• the roller compresses the hose offering fluid suction capabilities

• this creates a vacuum that forces the fluid to move toward the outlet

• once the roller is passed, the hose regains its original shape and dimension

The liquid never enters into contact with other parts of the peristaltic pump but exclusively with the hose. This means that the pump guarantees better sealing and a longer-lasting lifecycle, which is due to the prevention of possible damage to internal elements caused by corrosive or chemical substances.

Finally, thanks to its self-priming design, this pump is able to occlude the hose with its rotating roller thus blocking the fluid from flowing back.

Main applications of peristaltic pumps

Peristaltic pumps, due to their design, are ideal for all applications where the fluid needs to be dosed with precision and any possibility of contamination must be excluded, such as for food, medical, and analytical applications.

•In the medical field, peristaltic pumps are perfect thanks to their compatibility with fluids of different natures and viscosities. Thus, when using corrosive or chemical liquids, the risks of leakage or damage to the pump are limited. On the contrary, resorting to the peristaltic principle, it is possible to obtain excellent results in this field.

• Thanks to the precision and complete separation between the liquid and the pump, peristaltic pumps find widespread use even in those fields that operate in close contact with inks, enamels, glues, and paints.

• For water treatment-related applications, peristaltic pumps are useful because they're suitable not only with chemical substances used in these treatments but also with liquids that are dense or contain suspended solids, without any risk of damage.

• Finally, the food and beverage field also resorts to the peristaltic principle of these pumps for product pumping, transferring, and dosing purposes (such as with several beverages).

Advantages and disadvantages of peristaltic pumps

ADVANTAGES

the tube is the only part of the pump that wears out and can be changed rapidly

excellent suction capabilities

tolerance to small particles in suspension

the lack of valves and seals/gaskets means less maintenance

self-priming design

peristaltic pumps can handle corrosive and slightly viscous fluids

can also be used with delicate fluids. The dispensing is gentle thanks to the low shear forces, making them suitable for use with cutting-sensitive fluids

lower backflow and siphoning

peristaltic pumps are easy to clean and sterilize, thus guaranteeing zero contamination

dry operation is possible under certain conditions without damage

reversibility

DISADVANTAGES

due to the variability of the tubing, the pump system must be calibrated to reach an acceptable accuracy

due to wearing the tubing must be changed over time

if used extensively or without replacement, the tube may leak

a slight pulsation is unavoidable during the operation but can be reduced with the latest peristaltic pump technologies

the flow rate is sensitive to changes in differential pressure conditions

liquid viscosity might reduce the effectiveness of peristaltic pumps

Fluid-o-Tech peristaltic pumps

The Fluid-o-Tech peristaltic pumps of the TP series have a compact design that eliminates the need for a speed reduction gear motor, thus reducing noise, costs, space, and footprint typical of classic peristaltic pumps. It also offers maximum precision, outstanding mechanical characteristics, and perfect isolation.

The patented tube bed design minimizes pump pulsation and facilitates rapid tube replacement, inherently eliminating cross-contamination concerns. These features make Fluid-o-Tech peristaltic pumps ideal for equipment manufacturers (OEMs).

The positive displacement nature of peristaltic pumps allows consistent control of pump flow rates, which is proportional to speed.

Fluid-o-Tech recommends DC, BLDC, or stepper motors with its peristaltic pumps however other motor options may be used. We have experience in developing customized solutions to meet your specific needs.

Contact us for more information or fill out our information form.