Like Oil and Water, and Ethylbenzene?

Chemical Resistance Compatibility

Tips From the Service Bench

Technology TIP

When pumping liquids, you must be sure flow path wetted materials are compatible with intended media. If not researched and tested, issues may arise in the field that may impact product life and maintenance schedules.

While Chemical Compatibility Charts are a good place to start your research, there is typically a standard disclaimer at the bottom that limits their application and places the responsibility on you the buyer, such as:

Warning: The information in this chart is to be used as a guide, ONLY. Although believed to be accurate, actual decisions on material selection need to be thoroughly tested and evaluated by the customer for each specific application. It is the full responsibility of the customer to perform and evaluate the compatibility of materials for their specific requirements. The manufacturer takes no responsibility, etc., etc…


ARE WE COMPATIBLE?

Polymer components exposed to incompatible media can experience swelling or loss of physical properties. When severe, these effects can lead to degradation of pump performance, reduced pump life, leakage, and even pump failure. These issues are avoided with proper material selection. Many pump manufacturers provide a selection of flow path materials to meet most needs, and some provide additional material options for exceptional cases.

TESTING OUR RELATIONSHIP

So, how do you go about testing chemical compatibility? You can get test swatches of possible polymer materials. But, results using test swatches can be less than applicable since they may be much thinner or thicker than the actual parts used in pumps. KNF offers a better way to assist your compatibility decisions, with our Chemical Resistance Test Kit (p/n 173610). This kit contains our most popular head plates and elastomer valves materials. These are actual production parts in current use, so they offer the best test subjects possible. For each material, two parts are supplied – one for resistance testing, the other as a comparison reference. Simple instructions will guide you through the static soak test process.

Chemical Resistance Kit Materials

Kit materials: (1) PEEK (2) PPS (3) PVDF (4) PP (5) FFKM-A (6) FKM (7) EPDM (8) FFKM-B (9) FFKM-C

SUMMARY

In a typical fluidic system, component lifetime will be influenced by several variables beyond simple compatibility of the liquid media, including chemical concentration, liquid temperature, operating pressure, flow rate, and exposure to abrasive materials. A static soak test cannot, therefore, replace a long-term validation test with a pump running in a real system under system parameters. But, a static soak test is well suited as part of an initial screening to identify and eliminate materials which are clearly incompatible with expected liquids.

Contact KNF today for a Chemical Resistant Test Kit and get pumping with confidence!

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Liquid Waste Handling in Clinical Diagnostics and Lab Equipment

A new Application Note from KNF Neuberger, Inc. details effective methods for collecting, and evacuating liquid waste.

oem_application_noteWhen determining how to transfer liquid waste within an analyzer, design engineers must examine many factors. Though several methods will work, only one provides optimized system performance and lifetime.

Read more >>

 

Flexibility is Key: The NFB Family of OEM Pumps Expands with Two New Low-Flow, Compact Models

NFB boxer-type liquid pumps

Full line of NFB boxer-type OEM liquid pumps

With the recent introduction of NFB 5 and NFB 25, this powerful, compact line of two-head-one-motor boxer pumps now boasts a wider flow rate range of 5 mL/min to 1.3 L/min per head.

This widened range offers further flexibility to the already gymnast-like abilities of this versatile line of products, such as:

 

  • The boxer configuration offers the flexibility of two possible operating modes.
    1) In parallel mode, the alternating pump head operation results in smooth, even flow.
    2) In individual mode, two liquids can be transferred simultaneously.
  • An adjustable-speed brushless DC motor adds flexibility, allowing simple flow rate regulation, which helps to reduce lengthy testing, while improving time to market.
  • Further instrument integration flexibility is assured by the small size, two-for-one design…
  • …and the ability of these pumps to operate in any orientation.
  • The two-for-one design and long product life also create cost savings potential.
  • Need more flexibility? Contact a KNF engineer to discuss your specific design needs.

OK, after reading about all of that flexibility, it’s probably time for a nice cool-down stretch! Then, click here to learn more about the flexible, expanded line of KNF NFB boxer pumps.

A widened range of boxer pumps offers further flexibility to the already gymnast-like abilities of this versatile product line.

A widened range of boxer pumps offers further flexibility to the already gymnast-like abilities of this versatile product line.

Selecting the Proper Pressure Control Valve

KNF FDV Valves with PVDF materials

KNF FDV Valves with PVDF materials

Before deciding on the appropriate diaphragm pressure control valve for your application, it is important to first understand some of the basic uses of these devices. Gaining a better understanding of how a pressure control valve works, and determining how one can best suit your specific application, will simplify the selection process.

What Does a Pressure Control Valve Do?

When used in tandem with a pump, a pressure control valve provides more accurate control over the pressure supplied by the pump. Generally, pressure control valves can be used in the following 2 ways, depending on the application:

1) Pressure Control

A pressure control valve can be used to maintain constant back pressure for exact flow rates under free flow conditions, with positive pressure on the inlet side or with varying back pressure, or with the operation under vacuum, etc.

2) Bypass Valve

A pressure control valve can serve as a safety device for protection of a system’s pump, motor, tubing and connections, vessels and other accessories. Installed as a bypass valve, it prevents excessive pressure build up in the system caused by dirt, misuse or other problems.

Read more…

See You At AACC!

NFB 100 liquid diaphragm pumpNFB 100 liquid diaphragm pump with datasheetToday we’re packing up and preparing to send materials to display in the KNF Neuberger booth at AACC 2014, held this year in Chicago on July 29 – 31. Before we lock up the crate, though, we thought we’d take a quick break and mention that we’ll be introducing a brand new liquid diaphragm pump at the AACC show.  With two heads driven by one motor, this pump provides twice the flow and half the pulsation when operated in parallel mode. In the individual mode, two different liquids can be transferred simultaneously by one unit, eliminating the need for a second pump.

Please plan to stop by KNF Neuberger booth #4328 at AACC next week. For more information before the show, or to arrange
a meeting there, please click on one of the following links:

  • New NFB 100 liquid diaphragm pump.
  • Learn more about KNF air, gas and liquid pumps, designed to perform critical tasks for clinical diagnostic instruments and medical devices, such as liquid transfer, liquid aspiration, liquid dosing/metering, degassing, vacuum, and pneumatics.
  • Contact us to arrange a meeting at AACC Chicago.

See you there!

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:

Footprint:
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.