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Redesigned PCD Proportional Valve Driver Marries Trusted Functionality with Improved Control and Flexibility

The Humphrey Team is excited to announce the release of its redesigned ProControl™ Series PCD Proportional Valve Driver. 

Like the original model, the latest PCD proportional valve driver regulates the function of proportional valves through PWM or constant current signals. New navigation buttons provide operators with precision manual control and flexibility for various drive/control inputs. The valve and interface can also be controlled with various data acquisitions, including PLCs, IoTs or closed-loop systems.

PCD Proportional Valve Driver Features

The PCD proportional valve driver is exceptionally versatile. Its customizable interface can control a proportional valve on your test bench for evaluation and then transition to a production environment. You can also integrate the valve and driver into your system and use your DAQ output for valve control.

Input features

  • 0 to 5v, 0 to 10v and 4 to 20mA input options
  • Manual input control via navigation buttons
  • Valve presets for Humphrey valve models PV3, PV10, PC30 and iDP390/391 
  • Customized control mode for other proportional valves 
  • Signal conditioning via linearization attribute 
  • Screwless, push-button clamp connector
  • LCD screen and readout

Output features

  • Constant Current
    • 0 to 1 Amp
    • Dithering: 0 to 40mA
  • PWM
    • Frequency options: 500, 1.25k, 2.5k, 5k or 10k Hz
    • Duty Cycle: 0 to 100%
    • Dithering: 0 to 10%

Contact our ProControl™ application specialist at 1.844.447.9009 or email for more information and setup assistance.

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PCD Proportional Valve Driver

Humphrey Products Launches Updated Website

Kalamazoo, MI – Humphrey Products is committed to providing cutting-edge control products and services, including an innovative online experience.

We are pleased to announce the launch of our updated website, which features an improved layout and navigation to enhance the user experience. The content has also been reorganized to make it easier for users to find what they need. 

Users may now quickly peruse the newest products by category and search for tried and true products with the touch of a button in our upgraded online catalog, which features downloadable CAD and two-dimensional drawings, as well as data sheets and line cards. The expanded literature library includes additional product information available for download. 

Those needing assistance with valve selection or product customization can easily submit contact forms through the website, and clickable phone numbers allow for convenient calling from mobile devices. 

We look forward to your user experience feedback. Please contact us online or call 1.800.477.8707.


HK5/HKL5 Miniature Diaphragm Poppet Valve Offers Practical Solution for Alternate Media Application

HK5/HKL5 Miniature Diaphragm Poppet Valve The unique construction of the direct-acting HK5 solenoid valve makes it ideal for use in precise applications for clean, dry air, alternate media, and inert operation.

The miniature diaphragm poppet design flexes as it shifts, eliminating the need for sliding seals, seal wear, and metal-on-metal contact. This design ensures media integrity over a long service life.

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Solenoid Valves Offer Application Flexibility

The HK5 and HKL5 diaphragm valve series is a compact, flexible solution for controlling gases and fluids. Its multipurpose function and flexible construction make the solenoid valve series user-friendly. The design can offer zero leakage in specific applications. The HKL5 model is designed for compatible liquids and gases found in analytical instrument applications. Download the brochure for more information.

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HK5 and HKL5 Miniature Solenoid Valve Features

The Humphrey HK5 Series 2-way and 3-way, single solenoid valve provides performance and versatility for multi-media applications.

Product advantages:

  • Diaphragm-poppet design is inert to media
  • Versatile plumbing, electrical, and mounting features
  • Quiet operation 
  • Multi-function: 2-way or 3-way, normally closed or normally open, diverter or selector 
  • Excellent flow characteristics for a small, light, compact component: 85 LPM at 100 psi
  • Direct operating: stable performance throughout the spectrum of 28” Hg to 100 psi
  • Multi-million life cycle
  • RoHS compliant
  • Made in the USA

Application advantages:

  • Media is isolated from the solenoid
  • All wetted surfaces are inert materials
  • Low leakage with bubble-tight applications available


A Track Record of High-Quality Solenoid Valve Applications

Humphrey’s HK5/HKL5 Miniature Diaphragm-Poppet Valve has years of experience with difficult applications. Several Engineered Solution designs have been developed and centered around the flexibility and capabilities of the HK5.

Learn more with our case history illustrations of satisfied customer applications:

Complimentary Test & Evaluation Valve Offered for Qualifying Applications

This special offer is to the OEM design engineer seeking to test and qualify valves for a current problem or upcoming project. 

Our valves are ideally suited for the equipment or device manufacturer requiring reliable, cost-effective control of fluid media in their product... from basic compressed air and vacuum pressure through, to the more difficult control of liquid chemicals and cleaning agents. Compact in construction and designed for flexibility, the valves can be engineered to fit in when space is constrained.

To preview our wide selection of valve products, click here to access the online catalog.

Interested engineers are requested to complete the form below and submit. A Humphrey factory representative will call to assist with valve selection and shipment. 

Alternately, download the fillable form here and return it via fax or email, or call 800-477-8709 to speak with a sales representative.

Humphrey Offers Personalized Proportional Valve Application Assistance

Proportional Control Solenoid Valves are an excellent addition to any device or equipment, offering flexibility, precise flow conttrol, and economy not available from ON/OFF solenoid valve systems. Depending on need, finalizing a proportional control valve can become complex, particularly in critical or precision applications. For best results, a number of factors and conditions should be captured early in the specifying and testing process.

Proportional Valve Application Specialists can assist in shortening the process, based on their training and experience.

Here's our three step process:

STEP 1:DISCOVERY. They listen and learn specific application parameters and client expectations for valve performace. They will suggers a product to test.

STEP 2:EVALUATE. Specialists remains availalbe through client valve testing, and can assist with set up tips and answer questions on proper valve assessment.

STEP 3:FINALIZE. Compressible fluids include variables. Initial testing may or may not require adjustments and further optimization.Specialists knows what can be done and how to adjust valve performace.

BOTTOM LINE: Humphrey can help. Reach out to our specialists and streamline your understanding and use of proportional valve control "The ProControl Way".

Initiate contact with your ProControl application specialist:

1.844.447.9009 toll free

Download ProControl™ Products and Services Guide

Top Benefits of Pressure Balanced Direct-Acting Solenoid Valves

Do you need a compact valve that can achieve high flows, fast response times and tight sealing, no matter the media or pressure? Pressure "balanced" direct-acting solenoid valves may be the right choice for your application.

These universal, multi-purposed valves are available in inline, direct piping or manifold, subbase piping. Some specialized models offer protection against moisture laden and dusty ambient environments. Balanced Solenoid Valves offer several benefits:

Multi-Purpose Versatility – The balanced solenoid series is versatile with its many functions, including Normally Closed or Normally Open; 2- or 3-way; Diverter or Selector.

Optimum Performance, No Matter the Media – The series’ balanced poppet design achieves optimum performance whether the media is air or inert gases, clean, dry, lubricated, or contains some airline impurities.

Reliable Shifts, Tight Seals – Balanced solenoid valves neutralize internal forces generated by pressurized media. The shifting forces of the coil and return spring are optimized and need only seal the poppet to meet tight leakage specifications.

High Flow Capacity, Smaller Size – Balanced solenoid valves maximize internal flow path management. The balanced design coupled with an optimized solenoid magnetic circuit achieves significantly greater flow, within a reduced overall size.

Ease of Use – All electric and pneumatic connections of balanced solenoid valves are on opposing surfaces, minimizing total space occupied, and simplifying mounting and connections during installation.



Balanced Solenoid Valves can be applied to factory automation uses, packaging and testing equipment, as well as medical device and analytical instruments to accomplish a variety of functions. 

Are balanced solenoid valves right for you? Whether you need off-the-shelf or tailored valves to meet your exact requirements, Humphrey can help you design or select the ideal solution. Browse our online catalog to identify the products that meet the requirements for your specific application. Or contact us at 1-800-477-8707 for help in choosing the best products for your application.

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KRESA & Humphrey Partner to Enlighten Educators about the World of Manufacturing

In a pilot program, Humphrey Products recently partnered with the Kalamazoo (County) Regional Educational Services Agency (KRESA) to bring the attention of educators to the world of manufacturing in our home state of Michigan. On June 26th Humphrey hosted 20 teachers ranging from Kindergarten to High School Math and Science teachers, and from districts across the county, in an effort to help educate and inform them about the world of manufacturing. The program was facilitated by Kristen Garceau, Career Readiness Coordinator for KRESA, and David Maurer, Humphrey President and CFO. One of the goals of this partnership was to build a relationship with educators to help emphasize not only the importance of manufacturing but also the diverse workforce needed for success. As Dave Maurer put it, “As manufacturers, we have a strong need for a skilled workforce.  However, we cannot expect the education sector to know what constitutes a “skilled work force” unless we’re prepared to show them what that is.”  This pilot program is an effort to do just that.

KRESA Visit 2018

When we think of manufacturing, we typically think of people fabricating parts from raw materials and assembling components into products for sale. While skilled labor is fundamental, educators often overlook many of the supporting functions in manufacturing.  Functions such as:  Engineering, Sales & Marketing, Human Resources, Purchasing, Production Planning, Facilities Management, Safety and Compliance and Accounting. All of these functions require special skills and many manufacturers work hard to promote from within to fill these roles.   When educators can demonstrate the real world application of the concepts they are teaching, students will be better engaged in their learning and, hopefully, retain more of it as they continue to grow. 

The reality today is that manufacturing companies need a diverse influx of workers to both support their business and to grow it. Teachers are on the front line in helping students find their way to their future career paths. Through programs like this, teachers have one more tool to help steer young people to a path that they may not have previously considered or even been aware of.  Humphrey strongly believes this ultimately benefits both the student and employers.  After the success of this pilot, KRESA hopes to duplicate this model at additional manufacturers, as well as in other sectors of the local economy.

KRESA Visit KRESA Visit KRESA Visit 2018


KRESA & Humphrey Products partnering for a brighter tomorrow through manufacturing, education and understanding.

Proper Design Requires Knowledge of Valve Types

Some pneumatic valves are depended upon for saving lives—so don’t take chances when selecting the right one for your application.

Valves used in the medical device industry are designed with precise specifications so they are compatible with the requirements of the applications. Meanwhile, valves used in factory automation are designed to work within specific safety regulations. Every project has unique requirements and choosing the best pneumatic valve design for your application will provide optimum results. 

While each design has its strengths and weakness to be considered, knowing your application’s requirements is essential. For example, the media of the application varies between industries. Compressed air and other gases can be extremely powerful—even fatal—so understanding how the valve will be used is important. Certain valve designs are compatible but limited by specific media. Some other factors that dictate the required valve are the external variables such as temperature range of the application, and purity of the air or media (moisture, contamination). Once you know the critical requirements for the application, the valve design can be chosen based on its specific features.

Poppet-design valves

Poppet-design valves use a rubber molded poppet wrapped around the stem that moves along the bore of the valve, creating a seal when the poppet is in its seat. One specific advantage to using a valve with this type of internal design is the compatibility with a variety of media other than compressed air. The unique feature that allows this compatibility is less lubrication sensitivity due to few sliding parts or (dynamic seals).

Valves with a basic poppet design feature few sliding seals, and are pressure unbalanced.

Another benefit to this poppet design is that the valves are more tolerant of minor air sediment or debris. They also have excellent exhaust capacity and are capable of high flow rates. The poppet design provides a faster response rate due to short stroke and can be mounted in several ways.

Poppet valves more readily lend themselves to 2-or 3-way configurations, although 4-way configurations can be achieved by using dual 3-way poppet sets in one valve body. Poppet valves are typically unbalanced designs, which use the air pressure as the primary force to return the valve to a given position. This concept provides assurances that the valve will return to the desired position, even if the return spring fails. Balanced poppet valves are used to reduce actuation force and achieve lower current consumption in solenoid valves. Balanced valves typically provide smaller overall physical size and produce greater flow capacity.

Applications in which this design are most commonly found are in the medical device and analytical instrumentation industries, where air purity is required (absence of dirty or wet media/air), the need for reliability is mandatory (could be saving lives), low leakage rate is critical, and gases other than compressed air will be used as a medium.

Diaphragm-poppet design valves

Diaphragm-poppet design valves expand the poppet valves’ design by the use of a diaphragm. Its outer webbing guides the poppet to its seat without using sliding seals. Diaphragm-poppet designs are usually unbalanced providing the same assurance of return to a given position as the poppet valve. The diaphragm increases durability especially with different or non-lubricated media.

The diaphragm-poppet valve design has no sliding seals and is pressure unbalanced.

A variety of durameter and diaphragm compounds make it simple to modify a valve based on the environmental or application requirements for operation. Also, expect extremely low leak rates due to strong sealing control. Diaphragm-poppet valves make 2-way or 3-way configurations available, as well as the possibility of 4-way valves, by using dual 3-way diaphragm poppet sets in one valve body. This valve’s durability and reliability make it a great candidate for applications such as critical life support devices (e.g. heart ventricular support assistance or pulmonary supply devices).

Its non-lubrication capability makes it appealing to be used with devices used for respiratory and anesthesia gases. Diaphragm-poppet designs are great solutions in leak testing devices, due to the very low leak rate. Lastly, these designs are suitable for critical or contaminated vacuum applications.

Spoppet-design valves

Spoppet-design valves combine two designs to provide a blend of primary poppet sealing in conjunction with a minimal number of sliding seals, thus emulating characteristics of a poppet and spool valve design. Spoppet designs retain some unbalance characteristics but with some balance of pressure to reduce actuation forces. This design provides the benefits of the poppet valve with a reduced sensitivity to lubrication.

Spoppet-design valves combine spool and poppet concepts.

Only one sliding seal engaged at a time reduces the drag within the valve body. These designs can sometimes bridge the gaps or limitations of poppet and spool valves making them more useable in numerous critical applications. By blending the designs, spoppets provide more cost efficient 3-way and 4-way valves, and can be used in many different environments and applications.

Spool-design valves

Spool-design valves are available in two types: lapped-/shear-design with no seals or dynamic seals/O-rings. Spool valves are designed to be more cost-effective when manufacturing for 4-way valves and are conversely less adaptable for 2-or 3-way configurations. Spool valves can be either balanced or unbalanced, depending on desired position control required. Therefore, understanding this valves’ function is critical to the application requirements. Lapped- or shear-design spool valves can operate without lubrication but are less tolerant of variations in lubrication or by-products of compressing the air at the air compressor. Hence, further conditioning of the compressed air is required prior to use.

Valves featuring the spool design with dynamic seals require lubrication in balanced or unbalanced configurations.

Dynamic seal spool valves generally require lubrication. Lapped spool valves have higher leak rates that may make them unacceptable for control of medias other than air, or limited media sources (air/gas tanks/bottles). Consequently, these valve designs are better suited to applications in factory automation where the leak rates are not critical. The requirement for conditioned media also limits their use for vacuum where contaminates are ingested into the vacuum lines and valves.

Custom-designed valves

Custom-designed valves are becoming more common, using a combination of the fore-mentioned design technologies to provide solutions unique to the customers’ challenges. In a perfect world, off-the-shelf components would meet every application’s need. But that doesn’t often happen, especially when faced with trade-offs such as space constraints versus performance. Sometimes a complex solution is needed, such as squeezing multiple components into a small space or incorporating multiple valve designs for a solution.

Custom valve designs combine technologies for unique solutions.

Custom designs using known and proven design technologies offer the potential of lower cost pneumatic systems. Once the specifications are agreed upon with the manufacturer’s design engineers and the application’s product engineers, a custom designed solution may be the best way to meet the applications’ challenges if a specific design is close but not does not meet exact specifications.

Ultimately when it comes to valves, each design technology offers unique capabilities but not every design suits specific applications. No matter whether you are replacing a component or designing a pneumatic system, consult a valve manufacturer who has knowledge in many different design principles so that the best solution can be achieved.

by Willie Miller, Humphrey Products

Published October 19, 2011 in DesignWorld

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