Five Signs You Should Service or Replace Your Diaphragm Vacuum Pump

In a lab setting, vacuum pumps are expected to simply “do their job.” Often installed out of the way, they reside on shelves, in cabinets or behind the fume hood, where they transfer materials reliably, without a second thought. That is, however, until a pump eventually shows its age or malfunctions and it both literally and figuratively brings the application to a halt.

Recently, the team at Lab Manager asked us to identify the Top 5 Signs that You Should Service or Replace Your Diaphragm Vacuum Pump. This quick list is a great start, but we’d like to broaden the discussion a bit with the additional detail included below.

It’s vital for lab personnel to learn the signs of pump wear and tear. Addressing these symptoms as they take place can prevent significant downtime, costly repairs and even replacement. To keep your diaphragm pump system running optimally, monitor for the following five symptoms on a continual basis:

1. Increased bearing, motor or pneumatic noise levels.

a. Over time, as a pump wears, parts may begin to age and breakdown leading to increased operating noise levels. This is usually an indicator of the pump’s need for cleaning or standard maintenance. Consider changing the diaphragm and valves to return the pump’s noise level and performance to like new levels.

2. Slower processing or drying times due to wearing of diaphragm/valves, fouling of internal surfaces or leakage.

a. Diaphragms and valves should last a long time, but as they wear, the pump’s flowrate and end vacuum performance can suffer. Fouling of the internal surfaces may also hamper the performance of the vales and overall efficiency of the pump. This means that the pump requires more time to complete standard applications than when it was new. Changing diaphragms and valves and cleaning fouled surfaces can return the pump to like new performance. If the pump internal surfaces needed cleaning, investigate and eliminate, if possible, sources of particulates, fibers, etc., that are entering the inlet side of the pump.

3. Overheating (shutting down and restarting once the pump cools) from poor ventilation, incompatible power source or malfunctioning motor assembly.

a. KNF lab pumps are equipped with an over temperature cut off switch to prevent damage and help ensure safety. Overheating is a sign that a pump is not cooling properly, not functioning correctly or is laboring to achieve the desired performance in a given application. First check to make sure that the vents in the pump housing are not blocked or too close to a wall, etc. If the pump is properly ventilated and the power supply is appropriate to the unit, overheating can be a sign of possible issues within the motor. This pump should be returned to the manufacturer for a more detailed repair evaluation.

4. Blown fuses causing pump to shut down and not restart, due to over power or electrical short.

a. A blown fuse can indicate that a pump has been exposed to an incompatible power supply or uncontrolled power surge. If the power supply is appropriate to the pump and no power surge is detected, blown fuses may be a sign of an electrical short or malfunction within the motor. Repeatedly blowing fuses is an indicator that the pump should be returned to the manufacturer for further evaluation.

5. Slow start or stalling via startup against a vacuum or pressure beyond a pump’s capabilities, restriction of flow or blockage at the pump inlet/outlet port, or weak or damaged motor/capacitor.

a. Depending on the pump model, starting a pump against an inlet vacuum or outlet pressure may be an inappropriate use. Under these conditions, the pump may stall or start slowly causing it to overheat, underperform and/or blow fuses. Care should be taken to vent the inlet and outlet lines prior to starting and ensure that the valves and ports are free of blockages and contaminants. If the unit is normally capable of performing in this application, this may be a sign of a weakened motor or starting capacitor.


For more information about KNF Neuberger’s diaphragm vacuum pumps, visit

Laboratory, Meet Bluetooth.

In March, we discussed our expectations for Pittcon 2013, and noted how some of the emerging trends parallel the benefits of our SC950 and SC920 vacuum systems. Specifically, these vacuum systems make use of an industry-first Bluetooth controller, which promotes not just form, but function throughout the lab. Let’s take a look at the advantages this technology yields in a scientific setting, and highlight the benefits along the way.

First, and perhaps most important, is the idea that this provides more than just wireless control. Utilizing Bluetooth eliminates traditional line-of-sight issues as well. This is critical in the lab,


KNF continues to bring innovation to the lab, introducing Bluetooth control to vacuum pump systems.

where both lab equipment and colleagues vie for limited benchtop space. If the vacuum system is stored below the bench or in a cabinet, the Bluetooth still functions as required. This is thanks to the same low-powered radio waves used to control garage door openers, modern cordless  phones, baby monitors and more. Therefore, Bluetooth control can actually help free up bench  space, as it allows the controlled vacuum system to be moved to an out of the way location and  still perform as needed. With the vacuum operating out of sight, lab personnel can redirect their efforts toward other processes while retaining full ability to control the system at the simple  click of a button.

An ever-growing topic in the lab (and one we’ll be discussing at length in the near future), energy savings and green initiatives aren’t just driving the way labs operate, but also the way the
equipment within them are purchased and used. Thanks to Bluetooth performance, SC950
and SC920 vacuum systems can be operated within a fume hood without the need
for annoying cable feedthroughs. Fume hoods, which consume a large amount of lab
HVAC conditioned air, are a sizeable contributor of wasted energy expenses in the lab. The  SC950 and SC920 Bluetooth control allows the hood to be continuously operated at maximum  efficiency even when making critical system control adjustments. In fact, according to California  Institute of Technology, a variable volume fume hood is 60 percent more energy  effective when the sash is down when not in use1.

Finally, Bluetooth promotes increased lab safety as well. As mentioned above, SC950 and SC920 vacuum systems can operate within the  fume hood with the sash closed, and without the need for any tether or cable feedthroughs. This allows researchers to confidently work with  hazardous or toxic chemicals from outside the fume and with a barrier in place, simply making use of the system remote control for additional lab safety.

Remember, laboratory equipment continues to evolve. The integration of Bluetooth controller technology into a portable vacuum system  offers many benefits that can be applied throughout your lab. To learn more about SC950 and SC920, or to learn how KNF Neuberger continually drives lab efficiency via world class pumps and systems, visit



Oil-free Pumps Deliver Environmental, Cost Benefits in the Lab

With all companies increasingly focused on sustainability, selecting products – including those for the lab – that reduce or eliminate waste and save energy are becoming a top priority. While many labs have traditionally relied on oil-lubricated vacuum pumps, oil-free alternatives have become prevalent, in part, because they are better suited to comply with corporate guidelines for reducing carbon footprint. The  question, however, is what other advantages do these pumps provide and how do you select the best one for your application?

In most instances, the price of an oil-free pump, sometimes referred to as a dry pump, is higher than the oil-lubricated alternative. However, when you consider the process savings, lower user costs, and environmental benefits, oil-free pumps, such as the KNF LABOPORT® shown in figure 1, more than pay for themselves over the long life of the pump. Let’s review two key advantages in a bit more detail:

This applies to both the carbon version and the actual space in the lab. Eliminating oil means there is no risk for  contamination, and no  need for oil changes and subsequent expensive, hazardous material disposal. Also, they do not emit fumes that   contaminate the air. Oil-free pumps also are more compact, requiring less room on the bench, helping reduce the overall size of the lab in  some cases.

Operating Costs:
Considering the long life of pumps in the lab, operating costs should be a major consideration, especially in relation to  the actual purchase price. Less energy is required to run the oil-free pump, creating lower electricity bills for a lab. As oil-free pumps can be built to be corrosion-resistant, and again, since there is no need for oil changes and associated expenses, maintenance costs are lower, as  well.

Selecting the Best Pump for Your Application:
Now, there are many different oil-free vacuum pumps to choose from. Scientists and other lab professionals are not always sure which one is best for their application. A good first step is to select the manufacturer. Look for a manufacturer that understands the application and has the benefit of experience. This will help ensure the proper pump is selected for your individual lab requirements.

Selecting the proper vacuum level is also important. Many times, especially with older oil-lubricated pumps, the capacity and vacuum levels exceed what is truly necessary. Matching the vacuum to the application will result in more efficient operation and cost savings.

Also consider service. Of course, oil-free pumps are highly reliable, as many models can go 10,000+ hours without needing service. Some pumps, such as those designed and manufactured by KNF, can have a diaphragm replaced on site in a half hour with just a screwdriver.   There’s no hazardous materials handling and drainage, nor is a specialized service professional required to perform the work. Think of it as simply changing the filter in your air conditioning unit.

To learn more about oil-free diaphragm pumps and their advantages, visit the KNF Technical Library. There, you can review white papers detailing application- and market-specific data.

PITTCON 2013: Trends & Expectations

By: Dan McDougall, Senior Manager – Laboratory Products

PITTCON approaches, and we’re looking forward to showcasing our stable of laboratory pumps and vacuum systems. Conferences and  tradeshows always provide a great opportunity to meet with co-workers and customers from across the country –or the globe. Today’s  tradeshows involve a lot of prep; exhibiting is only a part of the responsibility. We continually find additional value at shows by ensuring a  full schedule of meetings takes place. This face-time is critical, and it’s incredibly beneficial to meet with customers to discuss their lab  systems and setups in detail.

Simultaneously, it’s important to “see” our industry right in front of us. Shows like PITTCON are the perfect venue to learn about industry  trends, and to see if last year’s innovations are now driving growth throughout the market. Ideally, we take note of market-shaping topics  and use them to identify new applications for our products, in combination with our own processes of building pumps and systems that serve  distinct industry needs.

This year, I’m very interested in hearing the latest developments in the push for sustainability and green initiatives. Though it has been  discussed for years, I continually hear about companies pursuing LEED certification. LEED, or Leadership in Energy and Environmental  Design, is a voluntary, consensus-based market-driven program that provides third-party verification of green buildings. Creating pumps  and vacuum systems –or a full business culture– that aligns with these principles is a part of our corporate social responsibility, and there  are KNF Neuberger products that correspond with this mindset.

We’ll be showcasing our SC950 and SC920 Vacuum Pump Systems at PITTCON this year.
These systems promoteSC950cmyk 6x6 green initiatives in the lab, operating without the need for oil or aspirator water. That way, there’s far less waste created during the vacuum process. They also provide meaningful energy savings, thanks to a brushless DC (BLDC) motor. Once the desired vacuum has been reached, the BLDC motor operates only occasionally to maintain that level instead of running at full speed. This reduces energy as well as wear and tear.

Also, SC950 and SC920 vacuum systems utilize a first-of-its-kind Bluetooth-enabled control, allowing lab personnel to install the systems within the fume hood, with the sash fully closed. Not only does this help reduce energy costs, it also promotes a safer working environment and increases much-needed bench space. In fact, both of the vacuum systems can be installed on a shelf or even in a cabinet, and eliminating annoying cable feedthroughs.

You can find KNF Neuberger at PITTCON booth #2502. We’d love to discuss any of these topics, or how we can help you in the lab.