100,000 Hours and Counting!

On February 4, 2005, KNF USA engineers entered the temperature-controlled space of the “Life Test Room” in Trenton, NJ to initiate prototype testing for a specially-modified version of the KNF N 838 series diaphragm pump. At the time, the custom-designed OEM vacuum pump was being developed for a Fortune 100 medical device manufacturer, as an integral component of their immunoassay and clinical chemistry analyzer. The KNF pump would need to perform its duty – vacuum aspiration of biological samples – quickly and quietly, while ensuring precision and durability over the life of the pump. Like all spec-driven KNF project pumps, the custom-engineered N 838 vacuum pump was to undergo substantial testing to ensure accuracy, reliability, and overall quality.

KNF Life Test Room

A peek inside the carefully controlled conditions of KNF’s Life Test Room

Among all tests performed by the KNF R&D team, the Life Test may be the most valuable as it simulates the rigorous operating conditions often found in real-world environments – providing valuable data which is used to further improve pump performance. KNF pumps that undergo this particular test are operated under a continuous duty cycle, at high load, in unfavorable temperatures. Collectively, these test settings amount to what KNF Engineers use to determine a “worst case scenario”. In short, the Life Test is employed as a means to identify specific opportunities for improvement, while simultaneously gauging the life span of the pump in its current configuration.

The specially-modified version of KNF’s N 838 diaphragm vacuum pump has been running in a controlled test environment since Feb. 4, 2005.

Remarkably, from the date this post is written, over 12 years (105,189 hours) have passed since Life Testing began for this special N 838 project pump. You read that correctly; the incredibly durable N 838 pump is still running strong after more than a decade! This impressive test run time represents the longest continuous duty timeframe ever recorded at KNF Neuberger. It should also be noted that this record-setting operating life was achieved with only a few minor updates including diaphragm replacements at 30K and 60K hours. Despite advancements in both pump technology and testing procedures, engineers at KNF will continue to operate this extraordinarily resilient pump, in the Life Test Room, until it has completed a full lifetime…whenever that may be.

To put this unbelievable achievement into perspective, we have compiled a list of historical events* that have occurred since the start of the N 838 project pump Life Test:

  • 2005 (Aug) – Hurricane Katrina makes landfall, devastating the US Gulf Coast
  • 2006 (Jul) – Twitter is launched
  • 2007 (Jun) – Apple releases the iPhone
  • 2008 (Nov) – The United States elects Barack Obama president
  • 2009 (Jul) – Roger Federer wins record 15th grand slam at Wimbledon
  • 2010 (Oct) – All 33 Chilean miners are rescued after being trapped for a record 69 days underground
  • 2011 (Apr) – Fidel Castro resigns from the Communist Party of Cuba’s central committee
  • 2012 (Nov) – Scientists detect evidence of light from the universe’s first stars
  • 2013 (Jul) – Detroit, Michigan becomes the largest U.S. municipality to file for bankruptcy
  • 2014 (Mar) – Malaysia Airlines flight 370 disappears kicking off the most expensive search effort ever
  • 2015 (Oct) – China announces the end to their one-child policy after 35 years
  • 2016 (Nov) – Donald Trump is elected President of the United States
  • 2017 (Jan) – World’s largest dinosaur footprint (1.7 meters) found in Western Australia

* events chosen, at random, from www.onthisday.com

Thread Seal Tape, a Fitting Friend

Tips From the Service Bench

By design, vacuum pumps pull gas or liquid in on the inlet side and expel media on the exhaust side. One prevalent issue to avoid, in order to ensure that the pump keeps operating to full potential, is keeping unwanted material out of the pump head and valves.

Many vacuum pump plumbing connections are made with hose connectors and fittings. One standard fitting thread is the National Pipe Thread (NPT). The threads on an NPT fitting are tapered for sealing, and are often used with a thread sealant, such as Thread Seal tape.

A recurring issue seen by our Service Department is loose Thread Seal tape unintentionally ingested into a pump (see photos below). The loose tape gets pulled in by the vacuum and lodges between the valve and valve seat. This can result in a loss of performance in the system and headaches for the pump user. The cause of this reduced performance is often not readily apparent, either.

Figure 1: Actual photos of ingested Thread Seal tape found within pump heads.

Once ingested, tape will not be expelled on its own as the path through the pump head is not designed to allow long/stringy solids to move through it. The removal of the tape debris involves disassembly of the pump head assembly, removal of the tape and re-assembly after inspection of all the components. This is time consuming and can be avoided.

One way to avoid ingested Thread Seal tape is to understand how the tape works in conjunction with the fitting and threaded port hole. The taper on NPT threads allows them to form a seal when torqued, as the flanks of the threads compress against each other. The fittings seal on the actual thread of the fitting and the hole. The fitting does not necessarily have to be installed to full thread depth as it is sealing on the thread itself.

DO’S

Figure 2: Apply Thread Seal tape

• Wrap the tape clockwise (facing the threaded portion) so that it follows the direction that the fitting will be threaded into the port (see Figure 2). Winding the tape in this direction will prevent the tape from unwinding during the tightening process.

• Use a Thread Seal tape that is narrow enough so it does not cover the first two threads of the fitting (see Figure 3). The first of the male fitting threads are the smallest in diameter and any tape wound onto these threads may actually be cut off as the fitting engages. The cut off tape may then be pulled into the pump head by the gas or liquid flow.

Figure 3: Correct application of Thread Seal tape

• Use 2-4 wraps of Thread Seal tape. You may need to adjust the number of wraps due to specific tolerances.

• Start the fitting by hand to ensure no cross threading occurs.

• Tighten according to fitting manufacturer specifications.

DONT’S

Figure 4: Incorrect application of Thread Seal tape

• Don’t wrap the tape covering the bottom of the fitting. Leave two threads free of tape (see Figure 4).

• Don’t feel the need to tighten fitting until the hex is flush. The sealing occurs on the tapered thread. It is OK if a few threads are left visible as long as the fitting is tightened to the manufacturers specified torque.

WRAP UP

Learning to apply Thread Seal tape properly will serve you well. When used properly, Thread Seal tape is a wonderful sealant. It is inexpensive and works in many different applications. It is easy to apply and lubricates the fitting and threaded hole assembly process. It also prevents possible corrosion at this interface and aids fitting removal.

>> View/download print-friendly (.pdf) version of this Technology Tip

Is It Time To Replace Your Water Aspirator?

A water aspirator is a simple device capable of creating a low strength vacuum for many standard laboratory applications. Though they are inexpensive to purchase and easy to use, the long-term operating costs and environmental impact of laboratory water aspirators can be quite significant.

The above video from Lab Manager follows Linda the Lab Manager as she and her colleagues investigate the real costs of owning and operating a laboratory water aspirator.

Former MythBuster Delivers Keynote at Pacific Design & Manufacturing Event

Former MythBuster Jamie Hyneman at Pacific Design & Manufacturing

Jamie Hyneman, former MythBuster, speaking at Pacific Design & Manufacturing event (source: Pinterest)

This year, guests of the recently re-branded Pacific Design and Manufacturing event received a special treat as Jamie Hyneman – the famed, former co-host of The Discovery Channel’s popular television series, “MythBusters” – delivered the keynote speech. During his speech, Mr. Hyneman communicated the value of hard work, and also referenced the importance of constant improvement through his own love of tinkering. The honorary Doctor of Engineering stated, “Science isn’t done by people in lab coats. It is done by people that want to do a good job at figuring something out”. With talk of science and tinkering, it is no surprise that the 2017 keynote speaker was able to connect with his audience. After all, there were thousands of engineers in attendance of the annual conference, most of whom share a love of tinkering.

Though Jamie Hyneman has since moved on from Myth Busters, and The Discovery Channel has stopped production of new episodes, it has not stopped millions of fans from holding the show in high regard for its creative and courageous (often crazy) engineering. For example, many at KNF recall an episode that first aired on July 12, 2006 titled, “Crimes and Myth-Demeanors (part 1)“. During the episode, the crew attempt to debunk robbery and break-in scenarios so often depicted in Hollywood movies. Things get interesting when Jamie Hyneman and co-host Adam Savage begin development of their own gadgets: super-magnets, and suction cups, respectively. The peculiar devices were custom-engineered to assist the show hosts with an air duct climb).

KNF N 828 vacuum pump

KNF N 828 vacuum pump

What makes this episode particularly memorable to KNF USA associates is the vacuum source used for Adam’s suction cups – a KNF N 828 Diaphragm Vacuum Pump! The lightweight, oil-free KNF N 828 vacuum pump performed admirably to spec, pumping to 100 mbar of absolute vacuum via the suction cups on Adam’s hands and feet. However, in the end, both co-hosts were unable to climb the flimsy air duct without considerable noise, thus being anything but stealthy. Another Myth Busted. Later in the episode, Adam used his KNF N 828 vacuum pump powered suction cup rig to climb eight stories up the outside of a glass building before becoming too exhausted to continue. But not before further demonstrating the power of the KNF N 828 diaphragm vacuum pump!

Video: Choosing the Best Vacuum Pump for Your Lab Application

 

Are you in the market for a new laboratory vacuum pump? Perhaps you need more information on which pump to choose. A new video, produced by Lab Manager, may provide valuable insights. View the video directly above, or click here.

New KNF Laboratory Products Catalog Available

KNF Neuberger Inc. has recently published an updated Laboratory Products Catalog. The 33-page catalog reflects the newly expanded range of laboratory products offered by KNF Neuberger, Inc. which includes: a complete line of vacuum pumps and accessories, liquid transfer pumps, dosing/metering pumps, rotary evaporators, and vacuum systems.

Organized by application, this comprehensive guide presents the best product selections for rotary evaporation/distillation, degassing, filtration/SPE, fluid aspiration, gel drying, centrifugal concentration, vacuum ovens, multi-user vacuum systems, and metering and transferring liquid. In addition, this piece includes handy product charts for easy comparison.

View the new Laboratory Products Catalog here. Or, request a high-resolution printed version via postal mail by completing the form below.

KNF OEM Diaphragm Pumps Used in Multiple Environmental Studies

A customer recently brought five environmental studies, ranging from 2013 to 1996, to our attention. Each of the studies details research conducted with one common component: a KNF OEM pump, which proved integral for sample collection or transfer during the analyses. Of the five studies, we cherry-picked two air-toxics studies for your further reading. However, here’s the listing of all five:

  1. Walter 2013 High Res Measurements Atmospheric Hydrogen West African Coast Mauritania
  2. Querino 2011 Methane Flux Vertical Gradient Mixing Ratio Measurements in a Tropical Forest
  3. Bailey 2010 Southwest Indianapolis Air Toxics Study
  4. Romashkin 2001 In Situ Measurements Long Lived Trace Gases Lower Stratosphere Gas Chromatography
  5. Elkins 1996 Airborne Gas Chromatography In Situ Measurements Long Lived Species Upper Troposphere Lower Stratosphere

KNF Environmental Pumps for Gas Sampling and AnalysisWe’re very proud KNF pumps are relied upon within ambient, source and portable devices for environmental sample collection and analysis. For example, the 2010 study listed above details a project in which the Indiana Department of Environmental Management (IDEM), the U.S. EPA, the City of Indianapolis, and a diverse group of stakeholders teamed up to conduct an air toxics study in southwestern Indianapolis, Indiana (this region was identified by the U.S. EPA National Air Toxics Assessment [NATA] in 1996 and 1999 to be an area of potential concern for cancer risk from air toxics).

A KNF pump was used to enable the analysis of the total non-methane organic carbon (TNMOC) concentration of ambient air. For a history lesson, the Clean Air Act Amendments of 1990 required the EPA’s Office of Air Quality Planning and Standards to set National Ambient Air Quality Standard for the “criteria” pollutant, ozone. In areas of the country where the NAAQS for ozone is being exceeded, additional measurements of the ambient nonmethane organic compound (NMOC) concentration are needed to assist the affected States in developing revised ozone control strategies. Measurements of ambient NMOC are important to the control of volatile organic compounds (VOCs) that are precursors to atmospheric ozone.

Therefore, a reliable pump was essential for the collection of air samples with potentially harmful toxics. Simultaneously, it was critical for the pump to collect samples in a manner that didn’t change or contaminate the samples. KNF pumps, known for their reliability and chemical inertness, are ideally situated for this type of application. Additionally, their extremely high gas tightness allows for the accurate and complete collection of media, without the risk of sample loss, dilution, or contamination.

Also, in 2001, a study, titled In Situ Measurements of Long-Lived Trace Gases in the Lower Stratosphere by Gas Chromatography, utilized the KNF NMP 830 pump (referenced as UNMP 830 pump in article) . For this study, a four-channel gas chromatograph measured different air qualities in 70 and 140 second intervals. Air external to the aircraft was delivered to the instrument from an external, variable speed, two-stage, KNF diaphragm pump, driven by a brushless 24-V DC motor. The KNF pump was mounted on the aft wall, and was turned on by the ACATS-IV onboard computer when the ER-2 aircraft ascended through 87 kPa of atmospheric pressure.

Regarding this second study, there are a few points of interest we’d like our readers to note. First, the usage of the pump is a prime example of KNF application flexibility. The KNF NMP 830 micro pump is small; however, its footprint isn’t the only reason it was relied upon within this challenging design. For example, the pump in this application is pulling atmospheric samples at an extremely high altitude, measuring parts per billion (ppb) and parts per trillion (ppt). Expectedly, pump inertness is therefore paramount. Much like in the first study referenced above, environmental analysis customers have come to rely on KNF pump material options, including PTFE and stainless steel, and on the leak tightness of KNF pumps.

Additionally, the KNF pump used in this second study is driven by a brushless DC (BLDC) motor, which helps meet the small size mandate. BLDC allows flow rates to be adjusted as needed, helping to extend the lifecycle and reliability of a device. Motor adjustment is also particularly important for this application, because at high elevations, fewer air molecules are available to blow across the pump for cooling. Therefore, the pump faces the risk of overheating. However, the ability to adjust and operate the motor at a lower voltage and speed helps to mitigate this concern. The small and lightweight design of KNF micro gas pumps even allows for energy-efficient battery operation.

Also of note, there’s far less ambient pressure at the elevation at which the pump in this study is operating, resulting in less pressure on both the top and undersides of the diaphragm. This condition is certainly not ideal for pump operation, which further adds to the difficulty of this application. This, and the other challenges presented by high altitude operation and ppb/ppt detection require a specification-driven, individually-tailored pump. KNF excels in designing and configuring pumps to exacting requirements such as these. In fact, over 80 percent of KNF’s business involves custom-engineered pump solutions.

To round out this review, the first and second studies listed above used KNF pumps to flush sample flasks prior to sampling, and to collect and fill flasks, respectively. The last study used a KNF pump to collect samples in a high altitude study with a set-up similar to the Romashkin 2001 study, which was discussed above.

Summing up this entry to The Pump Post, each of the five studies offers a constant theme of KNF OEM pumps being well-suited for environmental sample collection and analysis applications. Please check back to learn more about KNF products in real-world applications!