Please ensure Javascript is enabled for purposes of website accessibility

5 Questions (with Answers) about Rotary Lobe Pumps

rotary lobe pumps
by Eric Lunsford
February 26, 2021

Find Out More Information Regarding Rotary Lobe Pumps

In 2013, we had a customer in the snack food business. They approached us because they were using sine pumps that they had gotten from Watson-Marlow. They were using these on a peanut butter filling for their snacks. The maintenance manager indicated that these sine pumps were a maintenance nightmare. They were constantly rebuilding the pumps. More importantly, they were getting significant wear on these pumps. The maintenance manager said, “Someone is eating all that metal.”

That’s a concern. So we were able to convert his processes and his pumps over to lobe pumps. And these pumps have been successfully operating for them for over eight years now. It’s been quite a success—low maintenance and easy to clean, plus the lack of metal going downstream for this client and for his customers. The last thing we at Pye-Barker want our clients to worry about is how much metal their customers are getting out of their product. In this article, we’ll outline the advantages of lobe pumps.

What is a lobe pump?

There are a lot of different technologies of pump out there. The lobe pump is a great pump depending on the type of application you’re looking for. It has gears that don’t actually touch, so there’s not going to be any wear in there. It’s going to allow you to operate the pump in certain situations. As the cavities open and the gears come around, it’s going to create an open suction area. It’s going to pull that product in, allow it to flow around the outside edge, and as the gears re-mesh, it’s going to push it back out to the outside. Lobe pumps make a great application, especially in the food industry. They work well to pump a lot of different viscosity's of products across the board.

Why should you use a lobe pump?

One of the great things is that it has a large chamber, so it’s good if you’re pumping something like cherries or olives or something that’s got some particulates in there. If you were to use an internal gear pump, it would just chew that stuff up. Or say you’ve got a product like mayonnaise and you don’t want it to shear—you don’t want to chew it up, and you don’t want to degrade the product. You can run that through a lobe pump and it’s going to gently handle that product.

Lobe pumps allow you to pump without the chance of anything contacting anything else. There are two lobes that are tied together with gears on the backside, so they’re never going to come in contact with each other. You can dry-run that pump for a period of time and it’s not going to wear anything out because nothing’s touching.

Certain models are able to be cleaned in place (CIP). Some of them are designed to clean out of place (COP), where you pull the lobes out and flush through. So for sanitary hygienic applications, it’s great. Also, lobe pumps are good for a lot of different pump viscosity's and different fluids.

Lobe pumps give a pretty consistent product flow; there’s not as much pulsation as you might find in other pumping technologies. The product pumps so consistently that we’ve measured with a decoder to count the pulses, and we’ve found it’s extremely accurate.

Where should you use a lobe pump?

Ron has a lot of experience in the food and beverage industry—one specific example being in the bakery industry. They would use a lobe pump to pump eggs, liquid butter, margarine, and even chocolate.  They’d pump icings and fillings with varying viscosity's—sometimes they were light and fluffy; sometimes they were heavy and abrasive. Some pie fillings would even have chunks in it. Cherry filling, for instance, could be pumped through there without degrading the product.

Lobe pumps are great for hygienic applications. They’re used in pharmaceuticals, chemicals—anywhere you’ve got an application where you have a challenging viscosity or a product that needs to be handled in a certain manner. Cleanability comes into play, as well as pressures and temperatures. It’s got a wide range of applications. It’s a nice pump technology for industrial uses.

What are the benefits of the Wright Flow pump line?

When we talk about lobe pumps at Pye-Barker, we’re really talking about the Wright Flow pump line and their technology. They have multiple pumps out there—the TRA10 and the TRA20, which cross over with some of the other brand names identically. So if you need to match up with a different brand pump, Wright Flow is interchangeable and compatible. You can plug and play parts, pieces, or the entire pump.

Wright Flow allows you to use different seal technologies. If you have an industrial application, you need mechanical seals. If you have a food application, you need single O-ring seals or double O-ring seals because you’re running high pressure. If you’ve got applications where it’s high temperature, and you need Viton™ seals or rubber seals—whatever type of seal technology you need, Wright Flow has that type and the capability to do it on that pump.

If you’ve got a Waukesha U1 pump, our TRA10 is going to be an exact drop-in replacement. Even the parts and components swap out for those pumps. If you’ve got a different brand, we can usually match it up pretty closely or almost exactly. But some of them are identical swaps for the main brands or other brands that are out there that ours are identical to. They’re great pumps for those applications.

Wright Flow is excited about the revolution pump that they have. It’s compatible but it’s not an exact component replacement swap. But you can take one pump out, put the revolution right in, and you’re going to end up with a better pump right in the same spot. Slip it in, but it’s not going to be like you could pull the rotor off one and stick it on the other one.

There are numerous sealing options on the Wright Flow. Based on your product, if we’re looking for the solution to that, and we understand what the temperature is, what the pressure of that application is, and what the cleanability is, we’ll be able to specify what seal options go in that pump. Each of these pumps can come with a single O-ring seal, a double O-ring seal, a single mechanical seal, or a double mechanical seal. And the seal materials will even be changed based on temperature and pressure. Whatever you’re looking for, Wright Flow has a lot of different seal options for those pumps. And they’re very standard-style seals that are easy to maintain and easy to pop off and change.

CIP stands for clean in place. With CIP, you can leave the pump like it is. You won’t have to open or break it or anything. You can hook up your clean in place system and it will prove your flow parameters to your feet per second of flow, your residence time for chemical concentration, and the temperature concentration. You get a little ticket that proves that you met all those parameters for a clean in place process.

COP stands for clean out of place, where you’re going to open the pump up for cleaning. You usually just remove the rotors, you’ll run your flow through it, and then you put the rotors back in. Depending on your auditing body and/or parameters, you may be allowed to CIP or COP. In chemical applications, for washing between certain chemicals, you’re going to need to have a certain process to allow for that.

Wright Flow pumps are known for their clean in place ability. You’re going to choose your lobe design. If you need a CIP pump that can be cleaned in place, we’ll make sure you have the right lobe design and any back flush lines or jets needed for that to be cleaned in place. We’ll look at it and help you size your flow temperature requirements to make sure that it is going to pass your CIP for chemical residence, speed, flow—everything that you require for CIP. If not, then we can do COP as well, where you’re going to pull the rotors, pump through the system, and put the rotors back in afterward.

What materials are available on a lobe pump?

Stainless steel is obviously a more common one, but we have them in varying grades and different materials. It’s going to depend on your application and what you need it to be used for.

Lobe pumps are very low maintenance as far as what you need to do to them to keep them running. It’s a very simple operation. The seals are easy to work on and change. Your basic maintenance guy will have no issues at all with a couple of O-rings and an O-ring peg and basic hand tools, with changing these seals and putting them on and off. Because they’re non-contacting inside, there’s no metal going downstream. There’s no internal rotor wear. There’s no faceplate wear on these.

You’re going to want some sort of a relief protection downstream and/or a relief protection faceplate, depending on your application and the pressures you’re pumping. But the biggest thing is making sure you understand your application and that you size these appropriately for that application. You want to be looking at the right flow, the right pressure range, and the right temperature range for what your product is going to be. You want to look for the right flow pump—the Wright Flow pump.

For more information:

Call Eric Lunsford at 404-363-6000 extension 1217 or email him at

This article is a synopsis of a conversation between Eric Lunsford, President & CEO of Pye-Barker Engineered Solutions and Ron Wright, NW Georgia Territory Manager. Ron has 30 years of experience in industrial maintenance, 20 of those years in the industrial food industry. For the past five years, Ron has been helping clients solve problems as an industrial equipment account manager.

Request a Quote



banner image
banner image
banner image
Forest Park (Atlanta) Address:
121 Royal Dr.
Forest Park, GA 30297
FAX: (404) 361-8579
Sylvania Address:
452 Industrial Park Rd.
Sylvania, GA 30467
FAX: (912) 564-2636
Orlando, FL Address:
524 Mid-Florida Dr., Suite 204
Orlando, FL 32824
FAX: (321) 282-6424
Copyright © 2019. Pye-Barker Supply Company. All Rights Reserved.
Marketing by:
 S3 Media
Translate »
linkedin facebook pinterest youtube rss twitter instagram facebook-blank rss-blank linkedin-blank pinterest youtube twitter instagram