�ǳ�web Knowledgebase - NIV

Maximizing Precision & Flow Control While Reducing Heat Buildup in Chemical Analysis Systems

Rachel Desenberg — Fri, 21 Mar 2025 19:00:50 +0000

Category:

Imagine you’re designing an advanced chemical analysis system for a high-tech research lab. Your goal is to create a system that provides precise control over reagent flow, minimizes waste, ensures consistent performance, and guarantees high reliability throughout the process. This type of application demands a valve solution capable of precise mixing and controlling of reagents, while operating efficiently over extended periods without introducing variables that could compromise result accuracy.

After analyzing the demands of your application, you start evaluating your options. You need valves that can handle both gradient mixing and diverting applications, where accuracy in flow control is absolutely critical. They must also be able to withstand aggressive fluids, as your research involves a range of chemicals that could be corrosive or volatile. In addition, you want a valve that offers high cycle life, fast response time, and minimal dead volume to ensure consistency over time.

This is where �ǳ�web’s NIV Gradient Mixing Valve comes into play. The NIV series is designed with a unique, multifunctional diaphragm/poppet that serves as both a sealing membrane and a support for the poppet. This results in fewer moving parts, reduced dead volume, and longer valve life—all essential for high-precision applications. Given the complexity of your needs, you need something that won’t introduce unnecessary components or cause reagent loss, which is why the minimal dead volume of the NIV Gradient Valve is a major selling point. It ensures accurate mixing, minimizes waste, and enhances the efficiency of your experiments.

Energy efficiency is also a critically important consideration for your system’s long-term operation. Since your system will be running continuously, you want to avoid excessive heat buildup, which could compromise both your research and the longevity of your equipment. Even a minuscule amount of heat buildup can affect the stability of the sensitive reagents you're working with, potentially altering their properties and undermining the reliability of your results.

Since �ǳ�web’s isolation valves are designed with these concerns in mind, a Hit & Hold circuit is available as a standard option. This feature energizes the valve to full power for a brief moment, providing the necessary strength for precise operation, and then reduces the current to a lower, optimized level. This reduces the heat generated during continuous use, while still maintaining the exact control needed for your gradient mixing and reagent dispensing.

The Hit & Hold feature seamlessly integrates with the NIV Gradient Mixing Valve to optimize performance. It allows you to optimize both the energy consumption and thermal performance of your system without sacrificing precision or reliability. With reduced heat generation and lower power draw, your system can run efficiently over long periods, keeping your reagents at stable temperatures and preventing unwanted fluctuations in your results.

If your application requires precise flow control, minimal reagent waste, durability, and efficiency, �ǳ�web’s NIV Gradient Mixing Valve with the Hit & Hold option is a reliable, high-performance solution. This combination addresses the critical challenges of this type of application, creating a reliable and long-lasting chemical analysis system. It ensures that your system will maintain peak performance over time, all while keeping power consumption low, reducing heat buildup, and extending the life of your valves.

Ready to learn more? Contact us today to discuss your specific application, or click here to locate your nearest �ǳ�web distributor.

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NIV Series PTFE Isolation Valves with Hit & Hold Circuit	PIV Series PEEK Isolation Valves with Hit & Hold Circuit	NIV Series Gradient Valves with Hit & Hold Circuit	NPV Series Pinch Valves with Hit & Hold Circuit

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Precision Control Solutions for Commercial Inkjet Printing

Rachel Desenberg — Tue, 30 Jul 2024 19:51:21 +0000

Category:

Applications

�ǳ�web offers a variety of precision control solutions that resolve critical issues for commercial inkjet printing OEMs such as inconsistent ink flow, inefficient cleaning, uneven coating applications, and component durability.

Problem:

Inconsistent ink flow, inefficient cleaning, uneven coating applications, and inadequate component durability contribute to poor print quality and costly downtime.

Commercial inkjet printing OEMs face a variety of critical issues that significantly affect the quality and efficiency of their printing operations. The primary problem is often inconsistent ink flow, caused by air bubbles and blockages in the ink delivery systems. This inconsistency leads to frequent print quality defects and increased downtime for maintenance. Additionally, the cleaning system for the print heads and other components often does not effectively remove ink residues, causing frequent clogging. This reduces the lifespan of the print heads and necessitates more frequent replacements.

OEMs also often experience issues with the coating process for varnishing and laminating, which results in uneven application, product waste, and inconsistent finishes. In addition, the durability of the valves is often inadequate, leading to frequent replacements and increased operational costs.

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Solution:

�ǳ�web's precision control components enhance print quality and operational efficiency for commercial inkjet printing OEMs

To address these challenges, �ǳ�web precision control components are integrated directly into the OEM printing systems. For the ink delivery system, �ǳ�web’s PIV series valves, with their PTFE and PEEK bodies and absence of elastomers, are ideal for preventing the clogging issues that often result from ink drying on the valve poppet or orifice. This significantly reduces the risk of the valves leaking or sticking over time, ensuring reliable long-term performance. These valves are also ideal for use in the cleaning systems to control the flow of cleaning solvents to the print heads and other components. �ǳ�web media isolation valves efficiently handle various cleaning agents, ensuring thorough and effective cleaning processes that minimize clogging and extend the lifespan of the print heads.

�ǳ�web’s E2S series compact 10 mm media isolation valves can also be installed to regulate the ink flow from the storage tanks to the printing presses. These valves provide precise control and prevent air bubbles and blockages, ensuring a consistent and reliable ink supply. Additionally, the Cordis CPC series microcontroller can be integrated for ultra-high resolution and repeatable digital pressure control. This closed-loop system will maintain consistent pressure, further enhancing the ink delivery process and reducing defects.

For coating applications, �ǳ�web’s DR-2 series precision regulators provide fine control over the flow rates of coating materials, ensuring even application of varnishes and laminates. This reduces material wastage and achieves a uniform finish on the printed materials. �ǳ�web’s stainless steel push-quick fittings can also be installed to further enhance component durability and simplify maintenance. Constructed from high-grade 316 stainless steel, these fittings provide robust connections and allow full flow through the hose or tubing I.D., eliminating the smaller orifice often required in barb fittings.

By integrating high quality precision control components from �ǳ�web, commercial inkjet printing OEMs are able to realize significant improvements in their printing operations. The solutions �ǳ�web provides not only resolve existing problems, but also enhance overall efficiency, reliability, and quality of the printing processes.

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E2S Series Compact 10 mm Isolation Valve	Cordis CPC Series Electronic Pressure Controller	Stainless Steel Push-Quick Fittings	DR-2 Series Precision Regulator

PIV Series PEEK Media Isolation Valve

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Media Isolation Valves for Commercial Inkjet Printing

Rachel Desenberg — Mon, 30 Jan 2023 17:24:08 +0000

Category:

Videos

Most traditional process valves have difficulty with media—like ink—that dries quickly. Learn more about how media isolation valves can provide an ideal solution for these types of applications.

Video filmed at �ǳ�web in Cincinnati, Ohio

VIDEO TRANSCRIPT:

High-volume commercial inkjet printers use control valves to manage the ink-filling process. Ink is stored within reservoirs, and during the printing process, the valves release it and provide consistent flow to the print head. However, most traditional process valves have difficulty with media—like ink—that dries quickly. They typically require regular cleaning to maintain the dispensing equipment and prevent premature failure of the valves.

That cleaning is critical because in commercial printing applications, valves that fail to open or close, or valves that leak, result in thousands of dollars in lost production time.However, unlike traditional process valves, media isolation valves can be flushed clean. �ǳ�web’s NIV series isolation valves are widely used in medical applications where blood and other organic liquids prevent other types of valves from operating effectively or being thoroughly cleaned. These valves also work very well with other abrasive and viscous medias—like ink.

�ǳ�web NIV series are PEEK- or PTFE-bodied isolation valves that use a diaphragm plunger— also made of PTFE—to close off the media from the flow orifice. The design has zero dead volume under the seal and can be flushed clean. Unlike traditional materials such as stainless steel or brass, PEEK and PTFE have a unique, liquid-repelling quality that help prevent ink or liquids from sticking. This limits the opportunity for fluid to dry and ensures a long-lasting valve.

Due to its superior reliability, the NIV series is trusted in a wide range of demanding applications. �ǳ�web has the expertise and value-added solutions to meet your application needs. If you need assistance, please give us a call.

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Gradient Valves: A Versatile Solution for Fluid Mixing & Dispensing

Rachel Desenberg — Tue, 26 Jul 2022 18:15:34 +0000

Category:

Product Information

In fluid control systems, precision and reliability are essential. Gradient valves, also referred to as mixing valves or multi-stream vavles, are specialized devices designed to efficiently combine or divert multiple fluid streams. These valves offer a versatile solution for a broad range of medical, analytical, and industrial applications. This article outlines the function, design, and uses of gradient valves, with a particular focus on their role in mixing, stream splitting, and fluid dispensing systems.

What Is a Gradient Valve?

A gradient valve, or multi-stream valve is an advanced form of a mixing valve, designed to manage multiple fluid streams—either by combining them into a single flow or by diverting them to separate outputs. Unlike traditional valves that handle a single fluid stream, gradient valves allow for more complex fluid manipulation, making them ideal for applications that require precision mixing or fluid distribution.

Gradient valves are essentially a combination of multiple isolation valves, such as �ǳ�web’s NIV series. By integrating these valves into a single manifold, gradient valves can efficiently mix various solutions into one output or distribute a single inlet to multiple outputs. This combination simplifies the design and operation of fluid handling systems, improving both performance and reliability while reducing system complexity.

Video filmed at �ǳ�web in Cincinnati, Ohio

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Design Variants: Selecting vs. Diverting Applications

Gradient valves are versatile in terms of design, with the ability to support both selecting and diverting applications. In a selecting application, the gradient valve is designed to combine multiple independent inlets into a single common outlet. This configuration is ideal for processes that require the mixing of various fluids into a unified stream. For instance, in chemical mixing or reagent blending systems, the gradient valve can accurately blend different substances to achieve the desired concentration or chemical composition. Diverting applications use a single common inlet and multiple independent outlets. This design is commonly used for stream splitting, where a single source is distributed to multiple destinations. This feature is invaluable in automated applications where one fluid source needs to be directed to several systems or stages of a process.

Types	Design	Common Uses	Examples
Selecting Application	Multiple independent inlets combined into one common outlet	Processes that require mixing of various fluids into a unified stream	Chemical mixing or reagent blending systems
Diverting Application	Single common inlet with multiple independent outlets	Stream splitting where a single source is distributed to multiple destinations	Automated processes where one fluid source needs to be directed to several systems or stages of a process

Applications of Gradient Valves

Gradient valves are crucial in a variety of industries, particularly those dealing with fluid control, chemical processing, pharmaceuticals, and automation systems. Some common applications include:

Solvent Selection

Gradient valves can mix different solvents to achieve precise concentrations, ensuring optimal performance in sensitive industrial processes

Stream Splitting

In systems where fluid needs to be split across multiple channels for different processing stages, gradient valves provide a streamlined solution

Flushing Systems

Gradient valves allow for the controlled introduction of cleaning fluids in systems that require periodic flushing to maintain optimal performance

Automated Fluid Handling

Gradient valves enable automated processes by combining and dispensing fluids according to predefined requirements, improving efficiency and reducing human error

Key Features of Gradient Valves

�ǳ�web gradient valves consist of multiple solenoid-operated �ǳ�web NIV series media isolation valves integrated within a single manifold. Each NIV valve features a unique flexible diaphragm that isolates the actuation mechanism from the fluid path, ensuring precise control over fluid flows without contamination. This design protects sensitive components from harsh media while enhancing the valve’s durability and longevity.

These gradient valves are particularly well-suited for industries handling aggressive or corrosive fluids. The fluid paths are made entirely of PTFE (Polytetrafluoroethylene), a material known for its exceptional chemical resistance, thermal stability, and low friction properties. This ensures �ǳ�web gradient valves can withstand chemical reactions and handle a wide range of fluid types without compromising the integrity of the valve or system.

�ǳ�web gradient valves are available in various sizes and configurations to meet the needs of different applications. Orifice sizes range from 1/32 to 0.156", enabling precise flow control. Additionally, these valves offer a range of power consumption options from 1 Watt to 7.2 Watts, allowing engineers to select the optimal valve based on their system’s flow and power requirements.

Benefits of Gradient Valves

Gradient valves, particularly those incorporating �ǳ�web’s NIV series, offer several key advantages:

Space Efficiency

Integrating multiple valves into a single manifold significantly reduces the space required for installation, which is especially beneficial in applications with limited space or when a high density of components is needed

Reduced Leak Points

By consolidating multiple valve functions into one unit, gradient valves minimize the number of connections and potential leak points, improving the safety and reliability of the system

Simplicity

Instead of dealing with multiple individual valves, engineers can use a single gradient valve to achieve multiple functions. This simplifies maintenance, reduces system complexity, and enhances operational efficiency

Durability

�ǳ�web’s NIV series valves are designed for long-lasting performance, with features like a one-piece valve stem that centralizes the poppet and seals the diaphragm, resulting in fewer parts, reduced dead volume, and improved valve life

Gradient valves are essential components in fluid control systems that require the handling, mixing, or diverting of multiple fluid streams. Their ability to manage complex fluid routing tasks with precision makes them invaluable across a wide range of applications, particularly those involving corrosive, sensitive, or aggressive media. �ǳ�web’s gradient valves, which integrate multiple NIV series media isolation valves into a single manifold, offer unique advantages such as increased durability, space efficiency, and reduced leak points.

Whether used for solvent selection, stream splitting, or automated fluid handling, multi-stream mixing valves provide engineers with a reliable and efficient solution for optimizing fluid control systems. The integration of �ǳ�web’s NIV series ensures long-lasting performance, making these gradient valves an ideal choice for applications where precision, reliability, and chemical compatibility are critical.

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Gradient Mixing Valves	Media Isolation Valves

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DNA Sequencing

Rachel Desenberg — Wed, 13 Oct 2021 19:58:55 +0000

Category:

Applications

Did you know? �ǳ�web products are used in DNA sequencing to help enable early detection of diseases and better, more advanced treatments.

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Cordis High Resolution Proportional Controls	EV Series Electronic Valves	Eclipse Proportional Isolation Valves	NIV Series PTFE Media Isolation Valves

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The Advantages of Manifold Mount Isolation Valves

Rachel Desenberg — Wed, 09 Jun 2021 20:24:55 +0000

Category:

Videos

What are the advantages of manifold mount isolation valves? �ǳ�web Product Manager Attila Kiss explains in this quick video.

Video filmed at �ǳ�web in Cincinnati, Ohio

VIDEO TRANSCRIPT:

Hi, I’m Attila Kiss, product manager of pinch and isolation valves at �ǳ�web. We’re here today to talk about manifold mount isolation valves.

Manifold Valves Make Maintenance and Repair Easier

As challenges are faced in the system’s layout and design, one aspect that is often overlooked is the system’s maintenance and repair. Having to change a valve can be difficult, especially if you have to remove the fittings, tubing, wiring harness, and especially if the valve is buried in your system. Using a manifold mounted valve can make the process much easier, quicker, and more serviceable. When there are multiple valves in the system, you should consider accessibility for the maintenance and replacement of the valves.

Manifold Valves Save Time

Manifolding valves is a good option, especially when you have multiple valves in your system. Mounting the valves directly to a manifold allows for simple maintenance by removing just two screws and disconnecting the valve, as opposed to disassembling fittings, tubing, and the wiring harness. Manifold valves should conveniently be located in the service panel on an exterior face of your device.

Manifold Valves Reduce Leak Points

Other advantages of manifold mounted valves vs. individually ported valves are that there are less leak points, there is less internal volume, and since there is no tubing or fittings connecting the ported valves the system is much cleaner.

Thank you for watching. Contact us for more information on our manifold isolation valves, and don’t forget to subscribe to our YouTube channel.

Related Products
NIV Series PTFE Media Isolation Valves	NIV Series PTFE Gradient Mixing Valves

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PIV

Precise, Consistent Control Supports Cell Proliferation

Rachel Desenberg — Thu, 25 Mar 2021 18:47:36 +0000

Category:

Applications

Bioreactors are manufactured devices or systems that support biologically active environments. They are essentially vessels in which a chemical process is carried out involving organisms or biochemically active substances derived from organisms. Part of this process is sparging, which is the introduction of air, oxygen, carbon dioxide, and nitrogen to the cell culture media.

Problem:

Obtaining better control of the environment to better optimize cell proliferation

Optimal cell culture growth requires not only precise control, but also consistency. In this case, this bioreactor manufacturer was looking to enhance cell proliferation by improving both of these factors.

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Solution:

DV series valves provide exceptional precision and repeatability

�ǳ�web’s DV series valves were ideal for this application due to the exceptional level of precision, repeatability, and low leak performance they provide. Four DV series valves were selected to be used to control oxygen, air, carbon dioxide, and nitrogen being fed through the bioreactor’s sparger in order to control pH and dissolved oxygen (perfusion media) in the cell culture media during cell cultivation. �ǳ�web also configured a custom manifold to fit the application’s special mounting and porting requirements. The DV series valves enabled better, more precise, more consistent control over the critical parameters impacting cell growth proliferation within the bioreactor.

Pinch valves and proportional controls can also be used to automate the addition of perfusion media to cell culture media in order to optimize the proliferation environment. Additionally, precision proportional pressure controls are well-suited for maintaining the pressure and gas mixture in the headspace of bioreactors.

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DV Series Precision Electronic Valves	NIV Series Solenoid-Operated PTFE Media Isolation Valves	NPV Series Solenoid-Operated Miniature Pinch Valves	NPP Series Pneumatic Miniature Pinch Valves

Cordis Series Precision Electronic Controls	DR-2 Precision Regulator	EVP Series Proportional Valves	D VP Series Proportional Valves

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Precision Control for Liquid Extraction Applications

Rachel Desenberg — Tue, 29 Jan 2019 19:34:43 +0000

Category:

Applications

The field of liquid extraction presents unique challenges. While the separation of substances can be performed with a variety of different methods, these processes typically require precise control of multiple fluids within a single application. This can be complex, but �ǳ�web provides a simple solution.

Problem:

Selecting Between Multiple Solvents for Liquid Extraction

An OEM specializing in solvent extraction needed to select between multiple solvents as part of their unique vacuum distillation process. Due to the media being used, compatibility with a low leak solution was crucial to performance. The existing solution was cumbersome, involving three separate valves per line—fluid isolation valves, vacuum valves, and air piloted valves.

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Solution:

PTFE Mixing Valves Control Multiple Fluids

Laboratory productivity is a growing market where �ǳ�web delivers great value. In the field of liquid extraction, the separation of substances out of a sample can be performed with a variety of different methods. In this case, �ǳ�web's NIV series valves provided the perfect solution to select between the four different solvents required by the OEM's process. The PTFE valves provide inert and precise sealing for the fluid side, holding a tight leak rate as samples are passed from 50 kpa vacuum to 30 psig using nitrogen while the sample is injected to a heated extraction cell in its final stage. This solution eliminated the need for three separate valves per line, but �ǳ�web engineers were also able to further minimize the size—and reduce overall cost for the customer—by using a custom PTFE manifold.

Isolation Valves - An Overview of Different Types

Rachel Desenberg — Sun, 28 Jan 2018 19:24:07 +0000

Category:

Pneumatics 101

To control flow without contaminating media such as blood, pharmaceuticals or reagents, a wide variety of medical devices and analytical equipment utilize media isolation valves. This article explores the characteristics of three main types of valves commonly used to isolate media. By comparing the advantages and disadvantages of each, this article will provide useful information for determining which valve type will best meet the needs of a specific application.

Controlling Flow Without Contaminating Media

To control flow without contaminating media such as blood, pharmaceuticals or reagents, a wide variety of medical devices and analytical equipment utilize media isolation valves. Isolation valves are devices that isolate a valve’s actuation mechanism from the media being moved. They can be configured as simple 2-way devices or as multi-port selector/diverters, and are typically used in applications where a simple on/off function is required without the need to gradually modulate flow. These types of valves are well suited for many types of medical applications, including those that require precise, repeatable dispensing of media in analytical, diagnostic or therapeutic equipment.

What types of media isolation valves are available, and which is best suited for your requirements? There are two main types of “on/off” media isolation valves—rocker and diaphragm. Although not formally considered isolation valves, pinch valves meet the definition of a media isolated function.

What types of media
isolation valves are available,
and which is best suited for
your requirements?

There are many variables to consider when selecting an isolation valve. We will explore each of these valve types in more detail, comparing some of the advantages and disadvantages of each. This information will be helpful in determining which isolation valve type will best meet the needs of a specific application.

First, it is helpful to understand a few key concepts that describe some of the important characteristics of media isolation valves.

Dead Volume—The volume inside the valve that cannot be flushed during normal operation. Minimizing or eliminating dead volume is essential in applications where cross contamination is an issue, such as drawing diagnostic samples from multiple patients.

Internal Volume—The volume trapped inside the valve assembly when the valve is closed.

Swept Volume—The volume of the flow path within the valve assembly. A streamlined flow path where swept volume is equal to internal volume means zero dead volume.

Wetted Materials—Any material that comes in contact with the media flowing through the valve.

Rocker Style Isolation Valves

A rocker isolation valve is a solenoid-operated device that uses a rocker mechanism that pivots to seal the valve seat and isolate the flow path. As shown in Figure 1, rocker style isolation valves can be configured as simple 2-way devices or as multi-port selector/diverters.

Rocker isolation valves are generally smaller and more compact than diaphragm isolation valves, making them well suited for certain applications with specific space limitations. Some of the other benefits of rocker style isolation valves are that they can be relatively inexpensive, with low internal volume and fast actuation times. However, despite their low internal volume, rocker valves have more dead volume and are less well swept than diaphragm isolation valves. This causes them to have more carryover, which can be problematic for certain applications, as can an increased risk of cross contamination. Another factor to consider is that rocker valve designs include elastomeric seals, giving them a shorter lifespan and making them less chemically compatible than some diaphragm style valves. This type of isolation valve is most frequently used in industry for dispensing materials or to drive other larger valves.

Diaphragm Isolation Valves

A diaphragm isolation valve—also known as a "membrane valve"—is a solenoid-operated device that uses a diaphragm that extends and retracts to seal the valve seat and isolate the flow path. Like rocker style valves, diaphragm isolation valves can also be configured as simple on/off 2-way or 3-way devices.

Compared to the rocker style, diaphragm style media isolation valves feature much longer life, are better swept and have much less dead volume—some as little as zero. Another benefit of this type of isolation valve is that the diaphragm design can be made from non-elastomer materials such as PTFE, which eliminates the need for seals, providing increased chemical compatibility. This type of isolation valve can be constructed from inert materials, including an entirely inert fluid path. This makes diaphragm style isolation valves ideal for applications involving corrosive media.

When selecting this type of isolation valve, it is important to consider the diaphragm material and the media that will be used. Some diaphragm style isolation valves use an elastomeric membrane such as FKM or EPDM. The high flexibility of these types of materials allows them to tolerate small amounts of fine particles, but common chemicals such as methyl alcohol or ammonia can damage these types of diaphragm membranes. For chemotherapy treatments or other applications that involve corrosive media, specially designed non-elastomeric diaphragm isolation valves are available with more robust membrane materials, such as PTFE. When choosing a valve for use with corrosive media, it is important to identify that all wetted materials are inert. For the longest lifespan and lowest risk of cross contamination, the flow path and all wetted areas of the valve should be constructed of an inert material that is compatible with the media that will be used.

Pinch Valves

A pinch valve is a device that opens and closes the flow path by pinching a removable, disposable tube. Although not formally considered isolation valves, pinch valves perform an identical function by isolating the valve mechanism from the media through the use of this disposable tubing. Similar to isolation valves, pinch valves can be configured with single tubes as simple on/off 2-way devices or with multiple tubes as multi-port selector/diverters.

Pinch valves may be operated by electricity, air pressure, or manual operation. The operation power of electrically-actuated pinch valves varies greatly according to the application and size of the valve. Most draw anywhere from 0.5 to 10 watts AC or DC at a range of voltages—typically 12 or 24 VDC—and can usually run off a medical system's internal power supply. Pneumatically actuated pinch valves are the preferred choice in explosive/hazardous environments where a shorted or overheated solenoid could become an ignition source. They are also able to deliver more force, making them a good option for applications that require the use of firmer (higher durometer) tubing. Another advantage is size—since pneumatically piloted units are able to provide more force, the size can be scaled down to fit into smaller, more compact spaces.

For medical applications, pinch valves typically use medical-grade silicone tubing. If chemical compatibility is an issue other materials may be used, provided they match the pinch mechanism's original durometer and O.D./I.D. specifications. For example, media containing chloroform, ether, and some common alcohols will dissolve silicone tubing, however Neoprene tubing can be safely substituted.

By using the tubing as a gating element, pinch valves provide effective media isolation with zero internal or dead volume, without the need for a complex mechanism. This also allows pinch valves to tolerate significant levels of suspended particulates in the media they carry. The biggest benefit that pinch valves offer over isolation valves is that the tubing used in the pinch mechanism is easily replaceable in case of failure or need for stringent cross-contamination control.

Pinch valves also have a few drawbacks. For example, they may require more electrical power or air pressure to actuate than a diaphragm-style valve. They also tend to create an oval profile in the pinch tubing after repeated use, a phenomenon that can reduce the flow of viscous fluids and make the valve prone to clogs. For applications with media that contains larger particulates, Platinum-cured tubing is an excellent option as it is significantly less prone to this issue. Another factor to consider is that pinch tubes are quite soft (45-55 durometer) and cannot handle high-pressure media. As a result, the maximum allowable pressure is typically in the range of 20 to 30 psi for soft tubing.

Despite these issues, the sterility offered by disposable tubing makes pinch valves an excellent choice for many medical applications such as intravenous systems, drug delivery, and dialysis instrumentation. They are also frequently used in patient care applications such as sampling, dosing, and infusion.

Lifetime Considerations

Medical equipment is expected to operate reliably for long periods of time, so the operational lifetime of its components becomes an important design consideration. Like any other mechanism, a valve has a finite lifetime, but cycle life varies significantly between valve types. For example, media isolation valves with elastomeric diaphragms are often rated for hundreds of millions of cycles, while those with non-elastomeric diaphragms typically carry lifetime ratings in the 10's of millions of cycles. This is because the non-elastomeric materials (i.e. PTFE) are relatively soft and subject to accelerated wear.

Pinch valves also suffer from wear and tear, but most of that occurs in the pinch tube itself, which is designed to be disposable. This means that the operational life of a pinch valve is primarily limited by the lifetime of its pneumatic actuator or electrical solenoid—often rated in the hundreds of millions or even billions of cycles. The lifetime of the pinch tube itself varies widely according to the material it is made of. Neoprene tubing, for example, will start to deteriorate in several hundred thousand cycles while most silicone-based tubing can survive for several million cycles.

Applications—The Right Isolation Valve for the Right Job

Choosing the best valve for your application involves finding the best match between a design's requirements and the valve's characteristics. This is not always a straightforward process since so many variables are involved. For example, how much flow is needed, and what is the pressure of the media? Are there certain space limitations, specific power requirements or a minimum required response time or lifespan? What type of media is being used, and what materials of construction is it compatible with? Does it contain particulates? How much of a concern is cross contamination? Would disposable tubing be beneficial? The following table highlights some of the different characteristics of these types of valves and may be used as a guide for selecting the right type of valve to best meet the needs of a specific application.

Download Full White Paper (PDF)

By Attila Kiss • Product Manager, NIV, NPV, & NPP Series • �ǳ�web

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Pinch Valve

Video: Media Isolation Valves for Medical and Laboratory Instrumentation

Rachel Desenberg — Tue, 23 Aug 2016 15:08:32 +0000

Category:

Videos

Rob �ǳ�web, Vice President of Sales & Marketing, and Attila Kiss, NIV/NPV Product Manager, introduce �ǳ�web's new NIV Series of media isolation valves and discuss how this new series allows �ǳ�web to bring its valve expertise from the fluid power and control side of medical and laboratory applications to the control side of these devices for dispensing of media.

Filmed on location by Design World

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NIV Series Solenoid-Operated PTFE Media Isolation Valves	NPV Series Solenoid-Operated Miniature Pinch Valves

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Isolation

Q&A with Miniature Pinch & Media Isolation Valve Expert

Rachel Desenberg — Fri, 29 Apr 2016 17:55:13 +0000

Category:

Advertising

Attila Kiss, Product Manager for �ǳ�web's new NPV and NIV lines, talks about his background and experience with miniature pinch and isolation valves, and what he sees for the future of isolation valves.

Attila Kiss
NIV/NPV Product Manager
�ǳ�web Instrument Laboratory

What is your role at �ǳ�web?

I am Product Manager of �ǳ�web's new NPV Series Pinch Valves and NIV Series Isolation Valves. I work with everyone involved—from manufacturing and engineering, to sales and marketing—to produce the lines and ensure the final products are of the highest quality.

What has led you to your current position?

I have been working with miniature pinch and isolation valves for more than 25 years. I began in a family machine shop at age 12 and continued through high school, learning to manufacture components that were used to manufacture miniature solenoid valves. This taught me a great deal about machining very tight tolerance parts.

After high school, I enlisted in the United States Marine Corps where I repaired heavy equipment and developed a quality control system. When my time in the military was over, I returned to the manufacturing industry where I ended up at a valve company—first machining components, then assembly, and finally setting up a quality control department at Biochem, a solenoid valve company. From there, I went on to become Production Manager at Neptune Research, a pinch and isolation valve company. I spent more than 20 years there managing all aspects of their miniature pinch and isolation valve lines, including manufacturing, design, marketing and sales.

What part of your job do you find most satisfying and/or what do you like about working in this industry?

The most satisfying part is developing a product that could potentially save lives. I enjoy the travel, working with customers and other companies to custom design products specific to their needs. The challenge of developing new products and resolving issues with existing ones is very satisfying. Also, being able to share my machining knowledge on the manufacturing side makes new processes easier. I have always enjoyed building, tinkering, machining and producing an end product.

What makes miniature pinch and isolation valves such a great fit for �ǳ�web?

Many �ǳ�web miniature pneumatic products are already in use in the same machines and equipment that use pinch and isolation valves. It's a natural fit for �ǳ�web to provide the isolated side of applications with the same quality and reputation they have in pneumatic components.

What types of applications do you see for these valves?

�ǳ�web pinch and isolation valves can be used in many different applications where precise dosing or dispensing is a must, such as DNA synthesizers, HPLC equipment, gas chromatographs, blood analyzers and dental equipment. They can be used with liquids or gases, and are ideal for a variety of laboratory diagnostic equipment uses, including applications that test air, water or biological materials. They are also well-suited for a variety of printing applications as well as multiple industrial applications where the control of a fluid is required.

What makes �ǳ�web's miniature pinch and isolation valves unique, or how would you compare them to similar valves already on the market?

The biggest difference is the �ǳ�web brand and the high quality, fast delivery and excellent service that come with it. In addition, you will find that compared to most other pinch and isolation valves, �ǳ�web's valves consume less power and feature a smaller, more compact design.

What are �ǳ�web's delivery/turnaround times like compared to others in the industry?

The NPV and NIV lines are currently on a lean system at �ǳ�web, meaning that most product will ship within 2 to 3 days once an order is processed. Many competitors can take weeks or more to deliver similar products. �ǳ�web has the capacity and systems to provide what customers need, when they need it.

What kind of testing is performed on the these valves?

Every �ǳ�web isolation valve is tested for flow and decay tested with helium in a clean room environment, and every �ǳ�web pinch valve is bubble leak-tested prior to packing and shipping. There is no batch testing. Every isolation and pinch valve is 100% individually inspected and tested.

Where do you see the future of isolation valves?

As the baby boomer generation comes of age, more diagnostic equipment will be required, thus putting an increased demand on the miniature solenoid valve industry. I believe we will see an increase in smaller, more portable machines manufactured in the future to help the medical industry diagnose and treat patients faster and more efficiently.

If you were stranded on a desert island, what three things would you take and why?

K-bar, matches and canteen. K-bar is my Marine Corps fighting knife for hunting and survival, matches to make fire much easier, and a canteen to save water.

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