�ǳ�web Knowledgebase - eclipse

Products That Provide Proportional Control of Vacuum

Rachel Desenberg — Fri, 25 Feb 2022 20:28:13 +0000

Category:

Learn more about some of the different options available for electronically controlling vacuum in this quick video from Doug Paynter, �ǳ�web's Proportional Product Manager.

Video filmed at �ǳ�web in Cincinnati, Ohio

VIDEO TRANSCRIPT:

I am Doug Paynter, Proportional Product Manager here at �ǳ�web. Today we want to talk about electronically controlling vacuum. Here at �ǳ�web, we have the ability to provide all types of levels of products that help you control vacuum. Valves can be tested and shipped with as little a leak rate at
10^-11 utilizing our clean room helium gas detector system.

Now let’s talk about �ǳ�web’s EVP and DVP proportional valves. The more current that I apply to the valve, the more of an orifice I create. So I’m able to vary the amount of flow I let into the chamber or let out of the chamber.

We also offer our unique stepper-driven proportional valves that work with vacuum very well. The Eclipse, being designed with low-flow applications in mind, utilizes a ceramic material as the wetted parts. And so, very inert, and you can run different types of hostile gasses or fluids through it. And if you need higher flows, we offer the SCPV stepper-controlled needle valve. Both of them provide significantly higher resolution and work very well with vacuum.

For closing the loop, �ǳ�web can take a vacuum sensor and work with a comparative circuit to give you closed loop vacuum control. With the Cordis, we utilize an onboard micro controller, a specific transducer that we can interface with, whether it’s pressure or flow, and our own EVP, DVP proportional valves. The Cordis can now provide you accurate, repeatable, high resolution control of your Venturi circuit, direct vacuum, or your vacuum break applications utilizing either a digital or analog command.

The Cordis pressure controller can now be calibrated to pretty much any calibration within the application of vacuum control to whatever the application really calls for. Whether it’s in millibar or torr, or inches of water column, inches of mercury, negative to positive pressure or differential, or simply absolute pressure calibrations, the Cordis can now provide you closed loop control of your vacuum circuit.

For more information on how �ǳ�web can help you better control your vacuum applications, give us a call. Be sure to subscribe to our YouTube channel so you can see more riveting videos like this one. Thank you.

Tags:

EVP

DVP

SCPV

eclipse

CPC

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.

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

Tags:

CPC

eclipse

NIV

Flow Cytometry Application

Rachel Desenberg — Wed, 13 Oct 2021 19:28:58 +0000

Category:

Applications

Did you know? �ǳ�web products are used in flow cytometry to help provide early detection of blood-related cancers such as leukemia and lymphoma.

Related Products
Cordis High Resolution Proportional Controls	NPV Series Electronic Pinch Valves	Eclipse Proportional Isolation Valves	Air Volume Tanks

Tags:

What Is a Proportional Isolation Valve?

Rachel Desenberg — Sat, 31 Jul 2021 20:18:12 +0000

Category:

Product Information

When we talk about proportional valves, whether they are pneumatic or hydraulic, we typically refer to valves that vary their flow path when you apply an increasing or decreasing amount of power/current to the proportional valve’s coil. This input to the coil will generate an ever-increasing (or decreasing) magnetic field capable of moving the proportional valve’s internal poppet or spool-designed mechanism. For example, using a low wattage pneumatic proportional valve, 0-185 mA (nominal 0-10 VDC) can be used to generate 0-65 l/min @ 100 psig working pressure. Another means of proportional control would be using a stepper motor to position a needle or plate.

So, typical proportional valve performance provides smooth, repeatable control of all types of inert gases and media—or at least that’s true if we do not use the word “isolation” in the valve’s description.

There are all types of isolation valves in the field today—pinch valves, rocker valves, and diaphragm valves, to name a few—where their job is to ensure that whatever media is processed through the wetted area does not encounter any other materials that can contaminate that media.

Here are four contributing factors that all need to be considered first and foremost when designing an isolation valve:

Dead Volume: The volume inside the valve 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.

Taking in all the factors as we have mentioned earlier with isolation valves and now putting them toward a “proportional” isolation valve brings a next level of control and design for engineers to consider, especially during the medical/life science industry evolution we’re going through now. Providing the ability to vary the isolated wetted area's flow path is paramount to sensitive application success.

Whatever the means of isolation, eliminating the pulse, shock, and on/off characteristics of a standard isolation valve is achieved with a proportional isolation valve. It’s now possible to achieve soft start/smooth delivery of sensitive media to the test area. Proportional isolation valves can also provide enhanced close-loop results—compensating for various viscosities, repeatable flow rates, positive and/or negative pressure variation, bi-directional control, latching capabilities at specific flow rates, and more.

By DOug Paynter • Proportional Product Manager • �ǳ�web

This article was featured in Medical Design & Outsourcing

Tags:

eclipse

How to Achieve Ultra-Fine Proportional Control with �ǳ�web's Patented Eclipse Valve Webinar

Rachel Desenberg — Fri, 12 Mar 2021 19:44:44 +0000

Category:

Videos

�ǳ�web's award-winning Eclipse proportional isolation valve is ideal in critical liquid and gas delivery applications requiring ultra fine resolution and excellent repeatability. It is fully flushable with zero dead volume, features a specially-designed flow path with sweeping transitions, and all wetted areas are inert (ceramic). This makes the Eclipse well-suited for a variety of demanding medical, analytical, and industrial automation applications.

Related Products
Eclipse Proportional Isolation Valve

Tags:

eclipse

Proportional

EIV

Issuance of U.S. Patent for the New Eclipse Proportional Isolation Valve

Chris Agricola — Mon, 21 Dec 2020 15:35:28 +0000

Category:

Product Information

FOR IMMEDIATE RELEASE

Request Free Catalog
or Download Now (PDF)

Sign Up for Monthly E-News

Download Press Release (PDF)

�ǳ�web Announces Issuance of U.S. Patent for New Eclipse Proportional Isolation Valves

CINCINNATI, OHIO—January, 2021—�ǳ�web Instrument Laboratory, Inc., a manufacturer of Precision Flow Control products with focus in the medical, analytical, liquid/gas delivery, laboratory and industrial automation markets, announces that the United State Patent and Trademark Office (USPTO) has issued Patent No. 10,738,904 to �ǳ�web's new Eclipse Proportional Isolation Valve. The Patent, "Flow Control Valve Using Ceramic Valve Members", will expire in 2040.

The Eclipse is ideal in critical applications for liquid and gas delivery, medical, analytical and industrial automation requiring ultra-fine resolution and excellent repeatability. In addition, the unique design allows for custom flow profiles.

Patented ceramic sliding seal
Liquid and air capable
Leak free (<0.05 sccm)
Cycle life of typically >1 million
Repeatability: <0.5% of full travel
Highly customizable
Excellent Linearity: <4% of full-scale
Proudly made in the USA

Tags:

EIV

eclipse

patent

The Importance of a Soft Start for Critical Applications Requiring High Precision

Rachel Desenberg — Wed, 26 Feb 2020 16:44:06 +0000

Category:

Pneumatics 101

When a valve is cycled, one can observe the quality of control by measuring and graphing the flow leaving the valve and the input operating the valve, such as electrical current (for coil controlled valves) or steps (for stepper motor controlled valves). This paper will discuss the characteristics of a valve's performance curve—specifically, where flow begins and how the curve's trend can indicate certain valve features and their consequences.

When selecting a valve, there are many parameters to look at, but when sensitive equipment is involved and precision is vital to the application, such as in fluid analyses, characteristics of the flow's lift-off should be considered because initial flow can have a startling impact on the life and operation of the system overall. For example, if a valve allows an abrupt surge of flow, it can cause hydraulic shock (also referred to as water or fluid hammer). This can be seen in Diagram 1 where the circled area shows a sharp spike of flow occurring at the lift-off or opening of the valve.

Common Causes of Abrupt Lift-Offs

Abrupt lift-offs are typically due to how the internal sealing surface of the inlet (usually a nozzle) engages with the actuating sealing surface of the valve, which—most commonly—is a poppet with rubber adhered to its surface. Unfortunately, the nature of rubber (Viton, EPDM, etc.) lends itself to sticking, deformation, and degradation, which in certain circumstances results in the poppet clinging to the nozzle before sharply disengaging. Mechanical irregularities can also cause or contribute to a sudden increase in flow, but those are very specific to the design of the valve, such as spring or even frictional forces.

Certain types of valves have characteristics that make them better suited for reducing flow lift off or surge and hammer, such as gate valves, ball valves, or needle valves. To limit in-rush flow in your application, the valve's working orifice needs to be variable in its free area. A typical control valve, such as a poppet or spool valve, has a fixed orifice and therefore, lift on the seal face is working across the entire circumference of the orifice. This results in an initial spike in flow. For example, a 0.006 orifice with a 0.001 controlled lift would represent 6.5% full flow, equivalent to an abrupt lift-off or jump.

Flow Impact on System and Application

Hydraulic shock can result in vibrations, noise, and even pipe or seal rupture/failure. For sensitive systems especially, ensuring a smooth, consistent lift-off of flow is key, and not just for the life or maintenance schedule of the machine. Sudden changes in flow, however brief, can be especially detrimental and costly in control-critical applications, like medication or ventilation control, but also in instances where instrumentation is utilized to measure aspects of a system, such as miniature blood pressure cuffs. A sudden spike in flow could be too high and fast for a gauge to measure and relay in time, which will result in an inaccurate or incomplete reading.


Diagram 1: Abrupt Lift-Off		Diagram 2: Soft Start

Flow Impact on Medium

Sharp spikes of flow can also mean premature or excessive amounts of media entering the lines, which for critical applications, such as sample extraction, can waste expensive reagents/solvents or even result in inaccurate analyses. There is also the state of the medium itself to consider, such as blood or other sensitive fluids susceptible to hemolysis or homolytic fission, in which the cells or compounds within the fluid breakdown. Turbulence increases the loosening of chemical bonds, so minimizing disruptions or jolts in the flow will prevent the destruction or ruination of delicate samples. Thus, a valve for delicate applications must provide a flow profile that minimizes turbulent flow—protecting components, internal instrumentation, and fluid composition from damage. To accomplish this, "soft starts" are recommended (see Diagram 2). Unlike the prior lift-offs shown, a "soft start" provides a gentle introduction of flow before smoothly easing into a proportional flow rate (per current or steps provided).

Curve Consistency

Ensuring the flow curve follows the same trend valve-to-valve, especially lift-off characteristics, is important for consistency in production and for creating confidence in the product; after all, superior, low end control that allows microliters of flow is only superior if it is repeatable. However, one must also acknowledge that no two valves will perform exactly the same because no two can be perfectly identical; thus, there should be a range in which all valves will operate within instead. When selecting a valve, this range should be known and understood so that all valves within any given batch are adequately uniform and can operate as expected in a given application. This can concern lift-offs especially.

Therefore, whenever selecting a valve, it is important to be mindful of the valve's lift-off characteristics and consider whether or not it will support or hinder the application.

By Jess Koeniguer • Design Engineer • �ǳ�web

Related Products
Eclipse Proportional Isolation Valve

Tags:

soft start

eclipse

High Precision Fluid Proportional Valve

Rachel Desenberg — Tue, 10 Dec 2019 21:20:13 +0000

Category:

Applications

Applications:

Industrial / Medical Ink Printing
Precision Micro Fluid Mixing
3D Bio Printing
Precision Fluid Transferring
Dosing

Related Content

White Paper: How Stepper Motors Provide Precision Control
White Paper: The Importance of a Soft Start for Precision Applications
White Paper: Critical Aspects of a Valve's Internal Design

Related Products

Eclipse Proportional Isolation Valve

Tags:

Smooth Flow Control at Initial Start

Rachel Desenberg — Tue, 10 Dec 2019 21:03:30 +0000

Category:

Applications

Applications:

Gas Chromatography
Particle Counting
Mass Spectrometry
Low Flow Measurement Applications

Related Products

Eclipse Proportional Isolation Valve

Related Content

White Paper: How Stepper Motors Provide Precision Control
White Paper: The Importance of a Soft Start for Precision Applications
White Paper: Critical Aspects of a Valve's Internal Design

Tags:

Proportional Power Savings

Rachel Desenberg — Tue, 10 Dec 2019 20:45:31 +0000

Category:

Applications

Applications:

Mobile Analytical Equipment
Environmental Testing
Liquid Chromatography
Fuel Cells

Related Products

Eclipse Proportional Isolation Valve

Related Content

White Paper: How Stepper Motors Provide Precision Control
White Paper: The Importance of a Soft Start for Precision Applications
White Paper: Critical Aspects of a Valve's Internal Design

Tags:

Proportional

eclipse

Isolation

Ultra Low Controllable Range

Rachel Desenberg — Tue, 10 Dec 2019 19:51:37 +0000

Category:

Applications

Applications:

DNA Sequencing
Gas Chromatography
Liquid Chromatography
Particle Counting
Flame Ionization Detection
Microbiological Incubators
Micro Flow Cytometry
Environmental Process Chambers
Mass Spectometry

Air: 0.000487 l/min (487.5 µl) per 1/16 of a step
Water: 0.0002 l/min (200 µl) per 1/16 of a step

Related Products

Eclipse Proportional
Isolation Valve

Related Content

White Paper: How Stepper Motors Provide Precision Control
White Paper: The Importance of a Soft Start for Precision Applications
White Paper: Critical Aspects of a Valve's Internal Design

Tags:

eclipse

Eclipse 2-Way Proportional Isolation Valves FAQ

Chris Agricola — Wed, 16 Oct 2019 14:27:49 +0000

Category:

Product Information

What motor is used to control the valve?

NEMA size 8 Bipolar Hybrid Stepper Motor

Motor Specifications
Wiring: Bipolar
Step Angle: 1.8"
Winding Voltage: 2.5 VDS
Current/Phase: 0.49 Arms
Resistance/Phase: 5.1 Ohms
Inductance/Phase: 1.5 mH
Power Input: 2.45 Watts
Protor Inertia: 1.4 gcm2
Linear Travel/Step (resolution): 0.00006" (0.015 mm)

How long is the motor's wiring?

12" (304.8 mm)

What is the suggested method to control the motor?

A controller such as a PLC or microcontroller in conjunction with a bipolar chopper driver such as �ǳ�web's SCPVD-1 Stepper-Controlled Proportional Valve Driver. See SCPVD-1 Installation and Operations Manual.

What voltage should be applied to the motor?

The motor should always be powered using a stepper motor driver with a supply of 20 VDC, however 24 VDC can be utilized instead.

How do I zero the motor?

The valve can be homed by driving the motor clockwise until it reaches the hard stop (audible change). It is recommended to drive the motor at a lower current or voltage during homing procedures. The four-digit number at the end of the serial number is the number of steps from the motor hard-stop to initial flow, or the offset distance. A hard-stop can be reached on either end of the motor shaft, but the offset distance given is relative to the motor hard- stop. Direction of rotation can be determined by looking at the inset shaft on the back of the valve.

Why is the motor not moving as far as expected?

The driver may be set to micro-step. Refer to he Drivers Operations Manual for information regarding micro-step configuration.

What gases or fluids cannot be used in this valve?

Hydrofluoric acid*

* Other highly corrosive acids in high concentrations and
elevated temperatures may affect the ceramic components. Contact
�ǳ�web's Technical Sales Team with questions.

What is the rcommended way to clear or clean the valve?

Move to fully-open position and flush with water or detergent.

Which port is the inlet?

The Eclipse is bi-directional, however the calibration curve is recorded using the port closest to the motor (Port B) as the supply. Please note there are slightly different flow characteristics depending on which way the valve is operated. Contact �ǳ�web's Technical Sales Team with questions.

What hardware is included with the valve?

Two captured 18-8 stainless steel socket head screws, M.5 x 0.45 mm, 6 mm long, to secure the valve to an adapter or manifold.

What size Allen wrench is needed for the mounting screws?

2 mm

What adapters or fasteners are recomended for the valve's ports?

The zero dead volume model (P/N: EIVU-Z) comes with a ZDVF adapter which has 1/4-28 UNF ports for two flangeless headless fittings. �ǳ�web recommends a nut/ferrule combination from IDEX (P/N: XP-283X).

Note: The fittings must be flangeless, meaning the tubing does not flare on the end. Also, "Flangeless" style and "Super Flangeless" styles from IDEX are not interchangeable. The ports are 0.3125" apart so clearance necessary for installation and tightening/looseneing must be accounted for.

The manifold mount model (P/N: EIVU-M) can be connnected to a gas/fluid line by a custom-made manifold (using the manifold layout below) or by an EIV single-station manifold EUM-01 which has #10-32 UNF ports, or M-EUM-01 which has M5 x 0.8-6H ports.

Related Products
Eclipse Proportional Isolation Valve

Tags:

How Stepper Motors Provide Precision Control

Rachel Desenberg — Fri, 20 Sep 2019 18:45:56 +0000

Category:

Product Information

Stepper motors are used in a variety of applications to provide a means for tightly controlled motion. But what is a stepper motor, and how does it work? This paper will discuss bipolar motors in detail, explaining what they are and how they work, and providing examples of how they're used with different types of proportional valves to provide precise control.

What is a Stepper Motor?

Stepper motors are brushless DC motors that rotate in steps electronically set by a controller or drive, which provides the necessary current through electromagnets that are arranged in a ring as part of the stator assembly (the stationary portion of the motor). Stepper motors are ideal for applications that require speed and position control, especially at low speeds such as in automation, motion systems, and 3D printers. Due to their internal design which minimizes mechanical and electrical "delays" that occur in other motors, stepper motors have remarkable stopping accuracy and responsiveness. Often, this makes stepper motors an ideal choice for synchronous and high precision operations.

How do Stepper Motors Work?

Figure 1. Diagram of a Stepper Motor

At the core of a stepper motor is a permanent magnet and shaft down the center of two or more toothed rotors. These rotors have different polarities because of the enclosed magnet and are offset from one another to allow themselves to be better drawn to the electro-magnetized teeth that cover the internal surface of the stator. The stator has fewer teeth than each rotor to ensure full alignment can only occur in sections (stator plates) along coil pairs. Energizing and de-energizing in-turn coil pairs causes the shaft to rotate a full step due to the attraction and repulsion of the magnetized teeth.

How to Calculate Stepper Motor Steps

Figure 2. Step Angle Calculation

A step angle is the angle of rotation traveled in a single step. This can be calculated one of two ways—either by dividing the motor's full 360 degrees by the number of steps the motor takes to complete one revolution, or by dividing the motor's full 360 degrees by two times the number of rotor teeth times the number of stator phases (Fig. 2).

Microstepping

Simultaneously manipulating the currents through multiple coil pairs reduces the overall travel/rotation by attracting the teeth in two directions instead of just one, creating new half, quarter, eighth, or one-sixteenth step set transitions known as microsteps. Microstepping provides better resolution and reduces resonance/vibrations, but also decreases torque and can be detrimental to bare accuracy.

Stepper Motor Drives and Control

Energizing the coils of a stepper motor in the right sequence to achieve a single step is a complex task. As such, the actual control of the motor coils is typically achieved using a driver. There are two types of stepper motor drives—constant voltage (L/R drive) and constant current (chopper drive). L/R drives are primarily limited to low-speed applications, therefore, we will focus on chopper drives. If you're interested in learning more, this article provides a good overview of the difference between an L/R drive and a chopper drive.

Figure 3. Relationship Between Current Rise and Inductance

Drivers simplify the operation of a stepper motor by interpreting a digital step and direction signal from a controller and energizing the motor coils accordingly. All electronics are governed by Ohm's Law and the relationship between current rise and inductance (Fig. 3). With stepper motors, the motor's design (in regard to its coils) prevents current from increasing quickly during pulses (command signals), which means the current can never reach its peak value without very high voltage. This is a problem because without sufficient current, the torque will be low, especially at high motor speeds. To combat this, chopper drives perform what is known as Pulse Width Modulation (PWM).

Figure 4. Chopper Drive Voltage and Current

Pulse Width Modulation (PWM)

Pulse Width Modulation (PWM) involves turning the output voltage to the motor on and off very quickly at each step. This provides very high voltage to the motor's coils (usually 8 times more than the motor's nominal voltage) which causes the current to rise rapidly and be higher than it would be otherwise. This on-and-off action typically occurs at a frequency of 20 kHz or higher, but the voltage "on-time" is influenced by the coil's impedance and motor speed—thus at higher speeds the voltage is on longer (larger pulse widths) to produce an average current at the correct level (Fig. 3).

Stepper Motor Chopper Drives

Stepper motor chopper drives are regulated by a current-sensing resistor placed in series with each coil. The resistor develops voltage across itself which is then monitored by a comparator. When this voltage reaches a preset reference voltage, it is "chopped" (turned off) until the next pulse occurs. This enables the average current to be stable despite any variations in the power supply voltage and increases efficiency by ensuring the shortest possible intervals between current peaks and valleys.

Stepper Motor Linear Actuators

A stepper motor can have a threaded shaft attached to its rotating core which can then be used to push or pull a nut placed upon it, moving it axially. The pitch of the thread controls how far the nut can move per step, with the resolution/precision dictated in part by the step angle utilized by the stepper motor (full, half, quarter, etc.). Like most linear systems, a stepper driven linear actuator can be susceptible to backlash. Backlash is caused by "slop" or "play" between the threads on the nut and the threads on the lead screw. Having clearance between threads results in a dead zone when the direction of travel is changed. When reversing direction, there will be no movement in the linear actuator until the clearance between threads is removed (the threads make contact again). For this reason, it is recommended that the threads have as tight a tolerance as possible. Designers must work to balance the backlash and the friction that is introduced when tolerances are tightened.

Stepper-Controlled �ǳ�web Proportional Valves

�ǳ�web offers two different stepper-controlled proportional flow control valves, the SCPV Series proportional needle valve and the new Eclipse Series proportional isolation valve. �ǳ�web's SCPV Series uses a stepper motor to control the distance between a needle and a valve seat. Precise proportional flow is achieved by adjusting the position of the needle. Due to the type of stepper motor linear actuator used on the SCPV, it is not recommended to implement microstepping beyond a half step. Full stepping is recommended and equates to 0.001" of linear travel which will result in a flow resolution of 0.7 slpm air.

With �ǳ�web's new Eclipse Series, the stepper motor features a fine pitch linear actuator which travels a mere 0.00006" per step to move a special slotted ceramic plate. The ceramic is used to bridge two ports through a second ceramic plate beneath it. Proportional flow is achieved by adjusting the amount of overlap ("eclipse") between the slot and the ports. The Eclipse is designed to go from closed to open in approximately one-sixteenth of an inch, which equates to 1,125 steps of resolution. That number can be increased dramatically by implementing microstepping—switching to a one-sixteenth step will result in 18,000 steps of resolution. A single one-sixteenth step with this unique proportional isolation valve will adjust flow by roughly 13 microliters (µl/min) of water.

Although stepper motors may seem complicated compared to a standard DC motor, as we have shown, their basic operation is actually quite simple. Their unique internal design enables remarkable stopping accuracy and responsiveness, making stepper motors an ideal choice for use in a wide variety of applications requiring precise control.

If you have questions about stepper motors or want to learn more about using a stepper-controlled proportional flow control valve in your application, locate your nearest �ǳ�web distributor or contact �ǳ�web today.

By Jess Koeniguer • Design Engineer • �ǳ�web

Related Products
SCPV Series Proportional Valve	Eclipse Proportional Isolation Valve

Tags:

SCPV

eclipse

Pneumatic Solutions for Oxygen Mixing & Blending

Rachel Desenberg — Mon, 24 Nov 2014 20:03:46 +0000

Category:

Applications

The terms mixers, blenders and proportioners are synonymous when it comes to mixing two gases. Mixers are used in many applications across many industries; medical, welding, heat treating and food packaging to name a few. In the medical industry, O2 mixers are use to mix oxygen with other gases, including ambient air, for patient treatment. The mixers allow the doctor to go from a mixture of oxygen, typically from 21% to 100%. Most manufacturers are accomplishing this with modified needle valves that they manufacture.

easy replacement
needle valves

�ǳ�web has been manufacturing and supplying needle valves for a wide variety of applications for over 50 years. We now offer a cartridge style needle valve—the GNV Series—that is especially well-suited for these types of mixing applications. The standard GNV stem will allow knobs to be put onto the end, and added mounting features make it an easy replacement in most situations.

Need help incorporating a �ǳ�web needle into your product? Since we're the manufacturer, modifications are no problem.

proportional control for advanced mixing

For more advanced mixing, �ǳ�web offers two electronic proportional valves. The EVP Series is a #10-32 ported valve and is small in size. The EVP provides air or gas flow control and varies the output flow based on the current input to the solenoid. The consistent gain of the valve provides a high degree of control for mixing applications. The typical flow capabilities for this valve are 0 bubble tight to a maximum flow of about 23 l/min, based on pressures up to 100 psig.

Controllability and overall value are the main features of the EVP Proportional Series valves. The EVP Proportional valve may be controlled by using DC current, open or closed-loop control and even PWM (pulse with modulation).

For higher flow applications we have developed an innovative stepper-controlled needle valve, the SCPV Series. The flow of this valve is again 0 bubble tight to 300 l/min based on 100 psig inlet pressure. The flow resolution is 0.56 slpm per step, with a position resolution of 0.001 per step.

Contact �ǳ�web
Locate a Distributor
Download Whitepaper (PDF)

For more advanced mixing and blending applications that require media isolation,
check out the Eclipse proportional isolation valve.

Relevant Product Lines:
GNV Series	EV Series	EVP Series	SCPV Series

Toggle Valves	Flow Controls	Eclipse Proportional Isolation Valve

Tags:

EVP

SCPV

eclipse

�ǳ�web Knowledgebase - eclipse

Products That Provide Proportional Control of Vacuum

DNA Sequencing

Flow Cytometry Application

What Is a Proportional Isolation Valve?

How to Achieve Ultra-Fine Proportional Control with �ǳ�web's Patented Eclipse Valve Webinar

Issuance of U.S. Patent for the New Eclipse Proportional Isolation Valve

�ǳ�web Announces Issuance of U.S. Patent for New Eclipse Proportional Isolation Valves

The Importance of a Soft Start for Critical Applications Requiring High Precision

Common Causes of Abrupt Lift-Offs

Flow Impact on System and Application

Flow Impact on Medium

Curve Consistency

High Precision Fluid Proportional Valve

Smooth Flow Control at Initial Start

Proportional Power Savings

Ultra Low Controllable Range

Eclipse 2-Way Proportional Isolation Valves FAQ

How Stepper Motors Provide Precision Control

What is a Stepper Motor?

How do Stepper Motors Work?

Stepper Motor Drives and Control

Pneumatic Solutions for Oxygen Mixing & Blending

easy replacement needle valves

proportional control for advanced mixing

easy replacement
needle valves