How do EODD pumps compare to AODD on energy consumption?

A compressed air system converts only 10–15% of its input electrical energy into useful work at the pump. An EODD pump eliminates the compressor entirely and can deliver up to 80% lower energy consumption than an equivalent AODD pump on the same duty. For continuous high-run-time transfer applications, the EODD typically delivers payback within 12 to 24 months.

What is the difference between the Verderair PURE and the Verderair VA?

The VA is a general-purpose AODD pump available in both metallic and non-metallic construction with a broad material choice. The PURE is engineered for the most aggressive chemical duties, with PTFE wetted parts throughout and a non-metallic body. For concentrated acids, strong oxidisers, or solvents requiring maximum chemical resistance, the PURE is the correct choice.

Can a Verderair diaphragm pump handle solids?

Yes. Standard Verderair VA models pass solids up to 9.4 mm. HC-PURE sanitary models accommodate solids up to 25 mm. Hytrel diaphragms are recommended for abrasive solids duties to maximise service life.

What diaphragm materials are available?

The Verderair range covers PTFE, EPDM, NBR (Buna-N), Hytrel, Santoprene, and Neoprene. PTFE is the standard recommendation for aggressive chemical and high-purity applications. Hytrel is preferred for abrasive slurries. EPDM and Santoprene cover food, beverage, and general industrial use.

Are Verderair diaphragm pumps ATEX certified?

Yes. The full Verderair AODD range is available as an ATEX diaphragm pump in Zone 1 and Zone 2 certified versions. Both metallic and non-metallic body options are available in conductive materials to prevent static build-up in solvent and flammable fluid applications.

What is the maximum flow rate of a Verderair diaphragm pump?

The Verderair VA delivers up to 1,200 l/min at a maximum discharge pressure of 8.6 bar. Across the full range, models are available from below 10 l/min up to 1,200 l/min to match a wide variety of industrial duty points.

What is Verderair+ and how is it different from a standard air-operated diaphragm pump?

Verderair+ is an industrial air-operated diaphragm pump series built around a patented air valve design. Unlike conventional AODD pumps, the Verderair+ uses all available compressed air for moving fluid rather than wasting a portion through inefficient valve switching. The result is lower air consumption, quieter operation, and reduced running costs. It is fully manufactured in Europe, with an externally serviceable air valve that makes maintenance fast and straightforward.

What materials are available for Verderair+?

Verderair+ is available in both metallic and non-metallic construction, with a wide range of wet-side materials to match your fluid and application requirements. Whether you are handling aggressive chemicals, abrasive slurries, or viscous media, there is a material combination suited to your process. Contact a pump expert to discuss which configuration is right for your application.

Is Verderair+ ATEX certified?

ATEX certification is available across the Verderair+ range. Please refer to the individual model datasheets or contact our team to confirm the specific certification for the model and configuration you require.

How does the QR code on a Verderair+ pump work?

Every Verderair+ pump carries a QR code on the body of the pump. Scanning it gives you direct access to the ordering page for that specific pump and its compatible spare parts, as well as assembly and maintenance videos. It is designed to save time in the field, removing the need to search for documentation or part numbers manually.

Will I still have my personal contact person?

Yes. The customer portal complements your personal contact. Your usual sales contacts remain available as before.

Yes. The portal uses email verification and additional security checks during login. When signing in, you will receive a verification code by email that must be entered to access the portal. This helps ensure that only authorized users can log in. Access to the portal is restricted to approved users from your organization, and each user must create and manage their own account using their professional email address.

I don't have access to the customer portal?

If you do not yet have access or are unable to log in, please use our contact form.

I forgot my login details – what should I do?

Access to the Verder Customer Portal is managed through individual user accounts with email verification. Forgot your password? 1. On the login page, click “Forgot password”. 2. Enter the email address associated with your account. 3. Click “Submit”. 4. You will receive an email with a link to create a new password. 5. Follow the link and set a new password. No longer have access to your email address? Please contact the Verder support team so your access can be reviewed and updated.

Is there a charge for using the Verder Customer Portal?

The Verder Customer Portal is a free service for customers. There are no costs for using or accessing the portal. The customer portal is an additional digital order and information channel. Your usual sales contacts remain available for personal exchanges and to handle your business processes as usual.

What are the benefits of the Verder Customer Portal?

The Verder Customer Portal enables you to centrally and efficiently manage your pumps, spare parts, and orders throughout the entire lifecycle of your equipment. o Central overview of pumps, spare parts, orders, prices, delivery status, invoices, and credit notes o Direct access to all relevant information, documents, and technical data for your installed pumps o Fast and easy reordering directly from the installed pump or via order history o Accurate product and spare part selection tailored to your specific installation o Custom lists, printable overviews, and transparent processes o 24/7 availability with one‑click ordering o Secure login o Long‑term support for your pumps throughout their entire service life

Are IT security and data protection ensured?

Protecting your data is a top priority for us. The Verder Customer Portal uses modern security standards and email verification to ensure secure and controlled access. Specifically: Login requires your individual user account and password During login, a verification code is sent to your email address to confirm your identity Access is limited to authorized users from your company Each user must create and manage their own account using their professional email address User access can be deactivated immediately if required The portal only accesses the information necessary to provide the service This ensures that access to the portal remains secure, controlled and compliant with current data protection standards.

How does the login process work?

Access to the Verder Customer Portal is managed through individual user accounts and email verification. When signing in, you use your professional email address and password. During the login process, a verification code is sent to your email address, which you must enter to complete the sign-in. This additional step helps ensure that only authorized users can access the portal. This means in practice: Access is limited to authorized users from your company Each user must create and manage their own account using their professional email address Email verification codes provide an additional layer of security during login User access can be reviewed and deactivated when necessary The portal follows modern security and data protection standards This approach provides a secure and reliable way to access the customer portal while ensuring that only approved users from your organization can log in.

Why does my centrifugal pump deliver less than indicated on the nameplate?

This can have several causes. First, it must be checked that the pump is running in the right direction as indicated on the nameplate and manual. A centrifugal pump that turns in the wrong direction takes a lot of motor power, but delivers almost no flow. In addition, the capacity of the pump also depends on the speed of the pump. For the remainder of this explanation, we assume that the direction of rotation and speed are correct. The flow that a centrifugal pump delivers, is always a balance between what the pump can do and what the pipework connected to the pump allows. The pressure that a centrifugal pump (at a fixed speed) creates, will decrease slightly with the flow rate, but it is quite constant all in all. However, to push a larger flow through a pipe work, more and more pressure is needed. This necessary pressure consists partly of a static height difference (you want to use the pump to pump the liquid from low to high) and partly of friction losses. The static height difference is independent of the pumped flow, the friction losses with centrifugal pumps (which pump low viscous liquids) are usually quadratically proportional to the flow. So to pump twice the flow through a pipework, the pump has to press 4 times as hard, so 4 times more head is needed. When pumps deliver less flow than expected and than indicated on the pump nameplate, in practice the pump usually delivers the pressure indicated on the nameplate, but not the desired flow rate. The cause for this is not caused by the pump, but by an incorrect estimate of the friction losses. In other words: the pump delivers the expected pressure, but the pipework allows less flow at this pressure. In order to be able to pump the desired flow through the pipework, the pump would have to press harder, in other words more pressure is needed; requires more pressure than indicated on the pump nameplate. In other words, the pump delivers the pressure expected, but more pressure is needed to push the desired flow through the pipework. There are 2 possible reasons why a pump does not deliver the indicated pressure: - Either the pumped liquid is gaseous. Due to the gas phase in the liquid, the average specific gravity ρ is lower than that of water and the formula ρ * g * h produces a lower pressure. At higher gas concentrations, even a gas bubble collects in the impeller eye and the pump delivers even less pressure. - Either the pump is cavitating. Cavitation also collects a gas bubble in the impeller of the pump.

From which point is it better to switch from centrifugal to positive displacement pump (lobe/twin)?

In centrifugal pumps, the pressure is generated by centrifugal forces. These are themselves generated by the rapid rotation of the liquid in the pump casing. Centrifugal pumps therefore require speed to generate pressure. The greater the pressure required, the greater the internal fluid velocity in the pump. Viscosity creates friction in the fluid located between the impeller and the pump casing. This fluid friction creates resistance to spinning. So power is needed to overcome this friction. An increasing viscosity therefore increases the power consumption of the pump. This increase is all the faster at high speeds or therefore with pumps that have to deliver a high pressure. The impact of the viscosity on the power of centrifugal pumps delivering low pressure is smaller. Therefore, a centrifugal pump is not a good choice for generating high pressures with highly viscous liquids. With lobe pumps and screw spindle pumps, there is always a small play between the rotors and between the rotors and the pump casing. In order to make the pump as efficient as possible, these clearances are kept as small as possible, but to prevent the rotors from running into each other or in the pump casing, they are always present. These clearances form an open connection between the outlet and the inlet of the pump. With thin viscous liquids, these clearances between the rotors and between the rotors and the pump casing create an internal leak: some liquid is forced from the outlet of the pump (where there is a higher pressure) through this narrow passage back to the inlet. (where there is a lower pressure). This internal leakage rate increases as the viscosity of the pumped liquid decreases. Therefore, volumetric pumps are less efficient with low viscous liquids. The question now arises as to which viscosity a centrifugal pump is the better choice and from which viscosity it is better to choose a volumetric pump. The answer to this question is that it depends not only on the viscosity, but also on the required head and flow. So you cannot give a fixed viscosity value where it is better to switch from centrifugal to volumetric. With a high pressure head and a small flow rate, switching is better at a lower viscosity, while at a high flow rate with a low pressure head you can stay longer with a centrifugal pump. The example below should make this clear. When selecting a pump for 5 m³/h - 4 bar pressure, even with water (viscosity 1cP) less power is required with a rotary lobe pump than with a centrifugal pump. When selecting a pump for 40 m³/h - 1 bar pressure, a centrifugal pump still requires less power than a volumetric pump, even at a viscosity of 1,000 cP. In addition to the necessary power, the initial cost and maintenance costs also play a role in the choice of pump technology.

What is shear in a liquid and why is this important?

Shear is the difference in speed between 2 layers in the liquid. The degree of the shear is expressed by the shear rate, which represents the velocity gradient in the liquid. When 2 layers of liquid that are 1m apart have a speed difference of 1 m/s, then there is a shear rate of 1/s in the liquid between these 2 layers. As soon as a liquid is in motion, shear is created. The velocity is never the same for each liquid droplet, so there is always a relative movement of one droplet versus the other, thus creating shear. Even with so-called plug flow, shear will form on the wall because this wall is stationary or moves faster than the liquid and thus slows down or entrains the liquid. In pumps, there are moving parts as well as stationary housing. In view of the small distance between the moving parts and the housing, a large velocity gradient or high shear rate will develop in the fluid between them. The flow will also cause shear in the supply and discharge pipes, albeit a lower one. Shear cannot be avoided and is not a problem in itself. Sometimes a high degree of shear is even desirable. For example, in a high-shear pump a high shear rate is generated to form emulsions or dispersions, or in general, to mix liquids that are difficult to dissolve into each other more or less stably. However, the impact of shear on the microstructure of a fluid is not always positive or desirable. Shear, for example, can also damage sensitive liquids. Due to the shear stress between the liquid particles, an impact on the viscosity of the liquid is also seen in many complex liquids. Liquids whose viscosity is not influenced by the shear rate are called Newtonian liquids. They are typically chemically simple liquids: water, oil, sugar solutions, ... With much more complex liquids (preparations), the viscosity will decrease as the shear rate increases. These liquids are called thixotropic. As soon as the shear rate decreases, the viscosity increases again. The shear does not destroy the liquid structure and will not change it permanently. This means that a thixotropic liquid has the highest viscosity in a tank where it is at rest, so no shear. Due to the shear created by flow through a pipe, the viscosity decreases. In a pump, where the shear rate is much higher, the viscosity is at its lowest. When the liquid leaves the pump, the viscosity recovers as the shear rate falls back. With a small group of liquids, the viscosity actually increases with a higher shear rate. These liquids are called dilutant. Examples of dilatant liquids are honey and concentrated starch solutions. Due to their dilatant behaviour these liquids are very difficult to pump. The influence of the shear rate on the viscosity of these three types of liquids is shown graphically here:

What is the influence from speed on the pumpcurve of a centrifugal/rotary lobe pump?

The pump curve of a centrifugal pump gives the head, the absorbed power, the efficiency and the NPSH in function of the flow at a fixed speed. Usually the pump curve is published for water, or even: for a liquid with a specific weight of 1 kg / liter and a viscosity of 1 centipoise. With centrifugal pumps there is a formula to convert the pump curve from one speed to another: - Flow is directly proportional to speed - Head and NPSH are quadratically proportional to speed - Power input is proportional to speed to the power of three - Efficiency is independent of speed A lobe pump is a volumetric pump and therefore the flow rate delivered and the required power are initially directly proportional to the speed. This is also the case with highly viscous liquids and you can easily state that the flow and power vary linearly with the speed. The flow is the so-called stroke volume of the pump multiplied by the speed of the pump. The stroke volume of a rotary lobe pump is the volume of liquid that is moved per revolution of the rotors from the suction to the discharge of the pump. However, with thin-viscosity liquids, leakage occurs between the rotors and between the rotors and the rotor casing, causing the pump to deliver less flow. Before explaining the influence of speed on the pump curve with thin-viscosity liquids, we will first discuss the construction of the pump curve with water as an example. Per revolution, the pump initially moves the volume of water from the suction to the press again. However, under the influence of the pressure difference over the pump, a certain amount of water continuously flows back from the press (where there is a higher pressure) to the suction of the pump (where there is a lower pressure). This leakage flow rate is proportional to the square root of the pressure difference across the pump. So with a small pressure difference across the pump, this leakage flow rate will be small and most likely smaller than the flow rate of water the pump displaces through its rotation (the higher explained stroke volume * speed). Net, the pump still pumps water from the suction to the press. If the pressure difference across the pump becomes large, the leakage rate can exceed the volume the pump moves through the rotation and eventually net water flows from the press to the suction of the pump. In the graph shown here this is the case with a pressure difference greater than 7.5 bar. The leakage rate is independent of the speed. So if we increase the speed, then: - the flow we transfer from the suction to the press through the rotation will increase linearly with the speed - the leakage rate will remain the same Since the net flow the pump pumps is the difference between the two, the pump curves will shift upwards in parallel with increasing speed. You can see that visualized here.

Download Here Updates and New features Add dynamic update of time in Date/Time Settings page. Add settings restore icon UI button in Diagnostic page. Enabled I2T safety protection on motor. Allow to prime pump even when remote stop is active. Reduce flow rate updates to EEPROM in 4-20mA mode. Factory reset will be enforced at first run automatically. Implement settings restore function. Configure remote stop input pin settings based on user settings and add "Link Cable" option in Digital Output selection in I/O Settings page. Factory reset will be enforced at first run automatically. Implement settings restore automatically during firmware update. Add WiFi setup prompt on startup after factory reset. Implement WiFi module check at pump startup. Implement changes in 4-20mA high level input handling. Change 4-20mA output range for "Full Scale" mode. Implement adaptive motor feedback position error limit. Flash red LED quickly when display update has failed. Enhance RTC driver to reduce read time error. Improve contact pulse detection logic for more accurate timing. Change ADC sampling time to give a more accurate 4-20mA input reading. Implement logs upload to server via Device Update API. Implement maximum speed option in pump settings. Add boundary checking when setting maximum and current volume in fluid monitor page. Show alert pop up when fluid recovery is unavailable when there is no input in 4-20mA mode. Remove lower limit (10% of max speed) checking in setting 20mA scaling percentage. Log to flash when default calibration offset has been applied. Add "No Network" and "Scan Error" warning messages after a failed WiFi scanning. Add "PIN Code" label in WiFi setup page when returned from server. Change colours of the toggle switch. Show error pop up in operating page when motor failure is recovered during splash page. Flash red / white LEDs to indicate display update failure. Do not allow user to start flow calibration while prime tube alert is still on screen. Connect WiFi SSID with strongest signal strength. Display pairing PIN code in WiFi setup page for multi-tenancy support. Display WiFi setup prompt at startup if data reset to default because of settings version changed. Add “Total Pump Runtime” element in WiFi payload. Bug Fixes Fix in updating flow rate to server when selection arrow is pressed in Operating page. Fix flashing red LED when motor cable is disconnected at startup. Fix current volume in fluid monitor page not restored after a power cycle. Fix firmware update issue when hardware configuration EEPROM has not been programmed. Fix WiFi scanning issue after factory reset and WiFi setup prompt being skipped. Fix display corrupt issue after firmware update. Fix prime active / inactive logging on diagnostic page. Fix prime not working after flow rate changed by UP / DOWN arrow. Fix and align pump length to 10 characters in settings and UI. Fix issue in driver in reading motor registers. Fix issue in exported diagnostic log on USB flash.

I want to know more about Verder

Verder Liquids is a leading global manufacturer of industrial and hygienic pump solutions and part of the Verder Group. As a worldwide technology leader, we provide advanced pumping solutions as well as state-of-the-art analytical equipment to thousands of customers around the globe. Vital components, which help them to ensure economic, technological, and environmental progress. Day by day, to the benefit of many. Could there be a better explanation for our constant search for the better? Visit out Verder Group website

How can I contact Verder Liquids?

You can reach our pump experts via our contact form. They are more then happy to answer all your questions.

I am searching for documentation

Visit our Library; it contains literature, best practices, applications, manuals datsheets, brochures and more

What is the difference between an AODD and EODD.

An AODD is an Air Operated Double Diaphragm pump and an EODD is an Electric Operated Double Diaphragm pump. AODD pumps are driven by compressed air and EODD pumps are driven by a motor.

How can I order spare parts?

Write down the serial number of your pump and give us a call! We're always happy to help you.

Can I have a pump delivered on short notice?

Please allow 5 working days delivery time for our products.

Where are your pumps manufactured?

Our pumps are manufactured in Belgium.

How can I change a hose on my pump?

Changing a hose on your Verderflex pump is very easy. Please view our online tutorial. If this doesn’t help you, our pump experts can help you!

How does a peristaltic pump work?

A peristaltic pump is positive displacement pump that transfers a wide variety of fluids. This pump doesn’t have valves, seals and glands and it’s an inexpensive pump to maintain. Every peristaltic pump features flexible hoses or tubes, giving an open flow path which gives a high resistance to abrasion and permits the easy flow of solids and viscous media. Find out more about how a peristaltic pump works here.

How does a diaphragm pump work?

A diaphragm pump, also knows as a membrane pump, is a positive displacement pump that enables users in industries to standardize on a pump type that is suitable for a wide variety of fluids. The only requirement is compressed air supply. For more information, please visit our extended technology page.

What kind of pump is a Verderair pump?

Verderair pumps are air operated diaphragm pumps (AODD), delivering a smooth, reliable flow for all circumstances. The air valves design guarantees a perfect, non-stalling operation, even at low pressure. The air valves do not need any lubrication. Thanks to their unique design, the pumps are able to handle very abrasive and/or viscous products.

Are spare parts available for this pump?

Yes, spare parts are available to order for this pump. We offer maintenance kits, repair kits, dampeners, flow stop valves and all other relevant accessories. You can find more about spare parts here.

How do Centrifugal Pumps Work?

A centrifugal pump operates by drawing liquid into the center (eye) of a rotating impeller housed within a pump casing. As the impeller spins, it transfers energy from the motor to the fluid, forcing the liquid outward through centrifugal force. This action increases the liquid’s velocity, and as it moves through the pump casing, that velocity is converted into pressure. The pressurized fluid is then directed to the outlet and discharged at a higher pressure.

The core components of a centrifugal pump include the casing and the impeller—the latter being responsible for transferring energy into the fluid. Impellers come in a variety of designs, such as closed/channel, open, and screw-type configurations. These variations allow centrifugal pumps to handle a wide range of fluids, from clean, low-viscosity liquids like water to more challenging materials, including slurries, liquid chemicals, and even fluids containing larger solids like potatoes.

Question about how centrifugal pumps work?

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Types of centrifugal pumps

The different types of centrifugal pumps can be classified in several ways. One common classification is based on the type of impeller, such as closed, semi-open, open, vortex, screw, or channel impellers. Additionally, pumps can be categorized by the number of stages, distinguishing between single-stage and multistage pumps.

Another important classification is based on construction, including designs such as end-suction, inline, and split-case pumps. Furthermore, there are specialized versions, such as self-priming pumps, magnetically coupled (sealless) pumps, and specific designs like channel or screw pumps that are suitable for handling fluids containing solids or specific hygienic pumps.

What kind of fluids can be handled by centrifugal pumps?

Centrifugal pumps are versatile and widely used for handling a broad range of fluids. They are best suited for low- to medium-viscosity liquids such as water, chemicals, and light oils, but can also manage slightly contaminated fluids and, with the right design, liquids containing solids or fibers. Specialized configurations make them suitable for applications in chemical processing, wastewater treatment, and hygienic industries like food and pharmaceuticals.

Applications centrifugal pumps?

Centrifugal pumps are widely used for water supply, pressure boosting, and irrigation, as well as in wastewater treatment and HVAC systems. In industry, they handle chemicals, process fluids, and cooling water across sectors such as chemical processing, oil and gas, and power generation. They are also used in hygienic applications like food and pharmaceuticals, and for dewatering or slurry handling in mining and construction.

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