New Kids on the Block

TIPS FROM THE SERVICE BENCH

Phillips and Allen have dominated machine, sheet metal and cap screws for a long time. They are popular, easy to use and easily recognizable. But Phillips and Allen are looking over their shoulders! There are a couple of New Kids on the Block!

The new kids’ names are Torx and Pozidriv. The names may sound foreign but they fit right in the machine screw neighborhood. More surface area and better geometry make these screws more resistant to cam-out — or stripping — as it is more widely known. KNF is still utilizing Phillips and Allen head screws but Torx and Pozidriv are definitely making their presence felt.

TORX

Figure #1 (click to enlarge)

Torx are called “star drive” by some, as the recess resembles a 6 pointed star. The six points of contact engagement allows for higher torque being applied than a conventional Allen hex drive of the same size. Torx sizes are denoted by a T, followed by a number from 1 to 100. Common sizes used for KNF products include T6, T10, T15, and T25.

Various Torx screws and drivers are depicted in Figure #1 (left); shown clockwise (from top-left): various Torx screw heads, Torx handles, Torx driver, Torx black & white image.

POZIDRIV

Figure #2 (click to enlarge)

Pozidriv screws are almost a cousin to Phillips. The Pozidriv (sometimes spelled incorrectly as “Pozidrive”) is actually an improved version of the Phillips screw drive. The name is short for Positive Drive. This screw recess is very easy confused with Phillips if not noticed. Using a Phillips driver for Pozidriv screw recesses can easily result is a stripped head due to the different geometry of the driver itself. The Pozidriv has additional ribs in the driver tip which are received by the secondary web of the Pozidriv screw itself. This extra feature provides more turning strength due to the higher tool engagement. Figure #2 show various Pozidriv screws and drivers; shown clockwise (from top-left): Pozidriv screw heads, Pozidriv handles, Pozidriv driver, black & white image of Pozidriv.

Pozidriv drive bits are designated by the letters “PZ” plus a size code of 0, 1, 2, 3, 4 or 5. Common at KNF are the 0, 1, and 2 sizes. The drivers themselves will have a PZ marking and size code, and possibly the Pozidriv image on the handle butt.

The Pozidriv screws are visually distinguishable from Phillips by a set of radial indents set at 45° from the main cross recess on the head of the screw. These markings are sometime hard to see on plated or treated screws as the treatment may fill in the slighter 45 degree markings.

Please take care to look at these screws carefully before removing for service. Using the right driver will make your servicing quick and efficient. If you are in doubt of which screw is used on your KNF pump, please contact us. We are here for you.

WELCOME TO THE NEIGHBORHOOD

They don’t make things the way the used to, and this can be a good thing, since the latest tools usually incorporate technological advances that improve performance. Please give the “New Kids on the Block” a chance, they are proving to be hard workers!

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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

New Flow-Tight, Diaphragm Liquid Transfer Pump Prevents Uncontrolled Flow

New, FL 10 Diaphragm Liquid Transfer Pump Prevents Uncontrolled Flow

KNF’s newest liquid transfer pump, the FL 10, is leak-tight in both directions, preventing uncontrolled flow and back-flow of liquid media when not in use. The latest addition to KNF’s extensive line of diaphragm liquid transfer pumps, the FL 10 offers many advanced features, and provides a considerable advantages over similar competitive products.

Leak-tight Diaphragm Liquid Transfer Pump

Featuring a solenoid-drive, and leak-tight valve technology, the compact FL 10 liquid transfer pump displaces fluid at a flow rate of 0 – 100 mL/min. Additionally, a signal frequency modulation feature enables quick and easy flow rate adjustments, saving time and money. Finally, like all KNF diaphragm liquid handling pumps, the FL 10 is self-priming, dry-run safe, and maintenance-free – offering outstanding performance longevity and an extraordinarily long service life (10,000 hours or 1.8 billion strokes).

To learn more about the leak-tight FL 10 liquid transfer pump visit knfusa.com/FL10

KNF Exhibiting at the World’s Largest Printing Equipment Show

reprographic printingAs a trusted partner to many of the world’s leading industrial reprographic printer manufacturers, KNF is preparing to showcase its latest product developments at Drupa 2016. Considered the world’s largest printing equipment exhibition, Drupa is open every three years in Dusseldorf, Germany. This year, the show runs from May 31st through June 10th, and KNF is excited to be a part of it.

At the show, KNF will be exhibiting its latest product developments including liquid pumps with flow rates from microLiters/min to 12 L/min+ and gas pumps with flow rates from microLiters to 300 L/min. Additionally, KNF offers a wide selection of pumps that can be optimized for specific needs through engineer-to-engineer collaboration. Optional materials, motor types, fluid connections and other modifications are available to optimize performance, life, and cost at any quantity.

KNF liquid and gas pumps perform important ink handling tasks, including the ink transfer to print heads, ink degassing, print head cleaning, vacuum generation for print head meniscus control, and ink circulation. From continuous inkjet to drop-on-demand, from large format printing to product barcoding, KNF has the pumps needed for high-quality, consistent printing.

Please plan to stop by our booth in Hall 4, booth B01 if you will be attending Drupa 2016. To learn more about KNF pumps for reprographic printing visit www.knfusa.com/reprographics or read our related Application Notes:

Technology TIP: Measurement of Pulsating Flow

INTRODUCTION

TechTIP

Like most companies producing gas pumps, KNF uses glass tube and float type flowmeters to measure flow during pump production testing. This type of flowmeter has been used for several decades as they are fast-acting, reliable, and accurate. The normal industry practice is to calibrate this class of instrument using laminar flow. Unfortunately, the pulsating flow from reciprocating pumps produces an artificially high flowrate reading compared to the laminar flow calibration. As a result, all diaphragm and piston pump manufacturers using traditional flowmeters will end up promoting higher flow rate values than what the pumps actually provide.

OUR GOAL

measurement-flow-blogAt KNF, we are passionate about meeting the engineering design challenges of our customers. Our goal is to provide our customers with pumps that meet the actual needs of the system in which they are installed. Along with this goal comes the responsibility to provide data that best represents the performance capabilities for each pump produced at KNF. Simply stated, we want our customers to know the flow rate values we provide will accurately correspond to the actual flow produced by the pump — the true amount of gas delivered; not just an artificially inflated reading.

The flow measurement discrepancy manifests during system-level performance comparisons between continuous flow (non-pulsating) and pulsating pump types, reported to provide the same flow rates. The non-pulsating pump winds up delivering greater flow performance than the pulsating pump that was erroneously thought to be equivalent, skewing results in favor of the non-pulsating pump type.

TechTIP_MoPF_fig1

Figure 1: KNF pulsation-compensated flowmeter

THE SOLUTION

To address this situation, several years of research and development by our flow experts at the KNF Gas Pump Design Center in Freiburg, Germany has culminated in an advanced system for the measurement of pulsating flow. KNF has made an investment to implement this new technology. The resulting pulsation-compensated flowmeters (see Figure 1) are tuned and calibrated to measure pulsating flow more precisely than the traditional glass tube and float type flowmeters.

 

The more accurate flow readings from our pulsation-compensated measurement standard show lower values for flow than the laminar flow based systems used in the past. This document describes why your pump is still providing the same flow performance even though the measured and recorded flow value is lower. Glass tube and float type flowmeters are also called variable area flowmeters as the cross sectional area of the tube varies from smaller at the bottom to larger at the top (see Figure 2 below).

Figure 2

Figure 2: Cross-section illustration of a float type flowmeter

Pulsating flow always creates a higher reading in a float type flowmeter. The reason is that the float cannot move downward quickly enough between pulses. The float will remain on the top of the flow wave (see Figure 3 below). KNF has been aware of this phenomenon for quite some time and has been continually investigating better ways to attenuate the effect of the pulsation. The pulsation-compensated KNF flowmeter assemblies include physical components to minimize the effect of the pulsations.

Figure 3

Figure 3: Impact of pulsation on flowmeter readings

Simply put, our pulsation-compensated flowmeters are dampened to reduce the effect of the pulsations — these values are represented by the green line in the figure below. A dampened flowmeter may read pulsating flow too high if it was calibrated using laminar flow — that is why we use pulsating flow to calibrate our pumps at KNF. Flowmeters with little or no dampening will read artificially high as shown by the red lines.

SUMMARY

This advanced flow measurement system combines variable area flowmeters with a mass-flow calibration system. Optimized for pulsating flow, the system provides the most accurate measurement of flow available today. The improved accuracy is shown in Figure 4 (below).

Figure 4

Figure 4: KNF flowmeter reading (optimized for pulsating flow).

The chart shows flowmeters with a range of 2 – 10 liters per minute calibrated using pulsating and laminar flow compared to a target flow established by a mass flow meter. While this improvement is typical, actual results may vary across the flowmeter size ranges.

To learn more about KNF’s advanced flow measurement system please contact a KNF applications engineer.

Obtaining Optimal Process Pump Performance

KNF process pumps for hazardous media and environments

KNF N 860.3 FTI Ex – for pyrophoric gas application

In the latest edition of Processing magazine, KNF Process Pump Engineer, Rich Aerts highlights the importance of adapting a diaphragm pump to its operating conditions, media properties, and the needs of the process itself. The article includes a real-life example of pump materials being modified to achieve optimal performance, and illustrates the importance of gas-tightness in the manufacturing of pyrophoric processing gases.

Read article: “Transferring Pyrophoric Processing Media with Safety” (Processing, Sep. 2015) >>

Closer Look: KNF USA Process and Industrial Pumps

Our “About KNF USA” series comes to a close with its fourth and final chapter, a video snapshot of the Process and Specialty Products division. Richard Aerts, Process Products Engineer, walks you through options for reliable transfer, sampling, evacuation and recirculation of liquid and gas in critical—and often hazardous—industrial applications.

To explore further, download our Process Pump Catalog, or see our Process product line.

You can view the entire KNF Neuberger video library here.