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Achieve Efficiency with Humphrey’s Proportional Valve Driver

Proportional valve drivers offer precise control of proportional solenoid valves in pneumatic applications. The device is convenient for valve testing and evaluation, or for use as a control input interface on fixtures in production.

Basic Features of Proportional Valve Drivers

Humphrey Products’ PCD proportional valve driver is designed to interface with PLCs, IoTs and closed loop systems to control proportional solenoid valves, or to be used manually when testing and evaluating valves.

Humphrey PCD features include:

  • Control input choices: 0-5v, 0-10v, 4-20mA or manual
  • Presets for Humphrey PV3, PV10, PC30 and Servoid proportional models
  • A screwless, push-to-connect wire terminals
  • Real Time LCD Display
  • Signal linearization
  • Handheld design

Watch our product video to learn more information on those features.

Advanced Features of Proportional Valve Drivers

Set zero flow:  Removes dead band for improved resolution and valve performance.

Set take off: Compensates for low range voltage or inferior low end power supplies.

Set span current: Protects proportional valve from too much power if vulnerable to high current or voltage.

This video offers an analysis of each advanced feature of Humphrey’s proportional valve drivers.

The Benefits of Using a Proportional Valve Driver

  • Precision flow and pressure control
  • Quick response to input change
  • Versatile application across various industries
  • Real-time feedback for optimized function and energy savings
  • Convenient, easy to use device for operating proportional solenoid valves

Learn About Humphrey’s Proportional Valve Drivers

Our valve controller operates any proportional valve of one amp or less via PWM or constant current, or manually.

Consult our expert team to learn more about the advantages of our proportional valve driver and how the device design can suit your customer’s applications.

Call 1-800-477-8707 or contact us online for more information.

Proportional Valve Driver

How Cartridge Valves Optimize Medical Applications

As medical devices become more sophisticated, size and performance of media control components are critical selection criteria.

Cartridge solenoid valves can be extremely compact and modular in construction, lending themselves to greater flexibility with pneumatic and electrical connections in limited space. Their unique design can eliminate the need for external plumbing, while reducing the possibility of leaks.

These flexible, reliable valves offer high-performance capabilities in compact applications, making them ideal for use in medical applications.

Humphrey Products Cartridge Valve Features

Our 10mm and 12mm miniature cartridge-style pneumatic solenoid valves can be used in various applications and devices. The cartridge valve is made to adapt and is an excellent choice for compact single- and multiple-valve piping solutions.

Humphrey Products cartridge-style valve features include:

  • Two-way and three-way types
  • Normally open and normally closed functions
  • High-flow capacity
  • Unlimited porting flexibility in compact spaces
  • Fast-acting solenoid response times
  • Lightweight, 11 or 19.5 grams
  • Quiet switching

Benefits of Using Cartridge Valves

Easy installation: Cartridge valves integrate into manifold blocks that are designed with pneumatic passageways, and eliminating need for pneumatic fittings and tubing.

Compact size:  Cartridge valves are smaller and lighter than traditional pneumatic valves, minimizing the weight and mass of the device or equipment, making portable applications and reduced material handling possible.

Customizability: Cartridge valves can be integrated in a variety of functions allowing for simplified system design and operation.

Efficiency: Cartridge valves are designed with a minimum internal volume. Coupled with custom flow paths and volumes within the manifold, overall system efficiency can be improved.

Ease of maintenance: The cartridge design makes removing and replacing valves easy, reducing downtime and maintenance costs.

Humphrey Products offers cartridge-style valves and multiple cartridge valve subassemblies that are fully tested and ready to integrate into your device or equipment.

If your application has specific requirements that aren’t served by a standard cartridge valve, contact our Custom Valve Solutions team for additional options.

Red and white cartridge valve for medical applications

Understanding Solenoid Valves

What Is a Direct-Acting Solenoid Valve?

It’s a device used to control the flow of fluids, such as gases and liquids. Direct-acting solenoid valves convert electrical energy into magnetic energy to control the media flow through its ports. The valves have a copper coil, a plunger and a valve seat, or seal.

When electricity flows through the coil of a direct-acting solenoid valve, it produces an electro-magnetic field that attracts the plunger, drawing it away from the valve seat. That instantaneous event opens the valve so fluid can flow through. Once the electrical current is removed, the plunger returns to its original position, closing the valve.


Common Direct-Acting Solenoid Valve Applications

Factory automation: Direct-acting solenoid valves are suitable for industrial automation in manufacturing plants and assembly lines to control the flow of air, vacuum pressure, gases, fluids and chemicals for robotics, fixturing, test and measurement, cleaning and sanitizing.

Pneumatic and hydraulic systems: The valve’s ability to handle compressed and hydraulic fluids makes it ideal for enabling rapid actuation of cylinders and other actuation components.

Medical devices: Analytical systems, fluid control equipment and other medical devices that require control of liquids or gases for patient handling and medical procedures.

Automotive: Direct-acting solenoid valves can be used in fuel, transmission, braking and engine control systems to regulate fuel, oil, compressed air and other fluids.

HVAC systems: Solenoid valves can control refrigerants, air and water regulation, condensers and air-handling equipment in heating and ventilation systems.


Benefits of Direct-Acting Solenoid Valves

The top benefits of using a direct-acting solenoid valve include:

  • A compact, lightweight design
  • Simple operation
  • Application versatility
  • Energy efficiency
  • Responsiveness and reliability
  • Precision fluid control
  • Immune to pressure fluctuations


Types of Direct-Acting Solenoid Valves from Humphrey Products

Humphrey offers a broad, comprehensive line-up suitable for a variety of gas and fluid control needs:

  • Two and Three Way Types, Normally Open and Normally Closed at rest
  • Four Way, Directional Control Types
  • ON/OFF Types and Proportional (Variable) Control Types
  • Compressed Air, Vacuum, Mild Liquids and Gases, or Aggressive Liquids and Gases
  • Miniature, Small and Large Sizes (Flow Capacity)


Our Custom Valve Solutions

Humphrey Products has the expertise to provide custom valve solutions you need to suit your exact application requirements. We have decades of experience producing fluid-handling and pneumatic control valves and valve systems and thrive on collaborating on an engineering peer-to-peer level. We utilize advanced engineering tools to tailor our extensive selection of proven valve designs and sealing technologies.

Humphrey’s Life Science Group is dedicated to creating medical valve solutions for pneumatic and liquid control components and systems. Solutions for oxygen concentrators, respiratory devices, diagnostic devices, patient handling, medical device reprocessing and dialysis equipment have been successfully produced.

Browse our solenoid valve products and contact us to request more information.

General purpose direct-acting solenoid valves

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.

View Catalog


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.

Download Brochure


HK5 and HKL5 Miniature Solenoid Valve Features

The Humphrey HK5 Series 2-way & 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:

Optimize Your Equipment Performance with the Super Quick Exhaust Valve

Super Quick Exhaust Valve Applications, Benefits & Features

Our super quick exhaust valve is renowned for its responsiveness, extremely high flow capacity and long service life. This valve is designed to enhance the performance of corresponding pneumatic valves and cylinders.

Features of the Super Quick Exhaust Valve

  • Rugged, simple design
  • Engineered molded rubber shuttle
  • Long life cycle
  • Extremely high flow capacity
  • Quick dump of exhausting air for highspeed cycling
  • Versatile: function as quick exhaust, shuttle, check or speed controller

Super Quick Exhaust Valve Applications

This durable exhaust valve is well-suited for applications that require fast response times, precision pressure control and efficiency.

Exhaust valves can be used in:

  • Manufacturing equipment to manage the movement of robotic arms, conveyor belts and automated systems
  • Pneumatic systems that deal with compressed air to rapidly release pressure and control actuators, cylinders and other pneumatic components
  • Emergency stop systems to halt movement in machinery and help prevent accidents and injuries
  • Transportation systems to handle the movement of doors and other components

Benefits of Using a Super Quick Exhaust Valve

Improved response times: Systems can respond faster to changes in input because this valve allows compressed air or gas out rapidly. That’s important in applications where speed is critical, such as manufacturing and automation.

Improved efficiency: A super quick exhaust valve reduces energy consumption and operating costs by releasing pressure promptly and efficiently. It also prevents pressure buildup, which may damage equipment and cause safety hazards.

Improved Control of Media: A super quick exhaust valve incorporated in system design can sense pressure differential and respond immediately with controlled redirected flow.

Longer lifespan: The efficiency of a super quick exhaust valve is designed to drop pressure immediately to reduce wear and tear on system components, extending the lifespan of the system as a whole.

Increased safety: Emergency stop systems and safety controls require fast response times. Use of a super quick exhaust valve can de-energize the system immediately minimizing the risk of accidents, equipment damage and injuries.

Contact a member of the Humphrey Products team to learn more about our quick exhaust valves.

Download Product Info
Silver and 3-port super quick exhaust valves by Humphrey Products

What’s the Right Elastomer for Your Application?

Fluoroelastomer (FKM) vs Perfluoroelastomer (FFKM)

Fluorinated, carbon-based synthetic rubber materials, known as fluoroelastomer or FKM, emerged as a popular choice for high-performance seals in the late 1950s. Those materials can withstand temperatures greater than 200°C and are still used to manufacture O-rings, seals and gaskets for automotive, aerospace, energy and other industries.

In the 1970s, DuPont™ introduced Kalrez®, a perfluoroelastomer or FFKM compound, as the gold standard elastomer for high-performance seals in aggressive media environments. FFKM has since been enhanced for even greater performance and is more widely available.

What is a Perfluoroelastomer?

FFKM has a fluorinated backbone and higher fluorine content than the FKM compound, which allows for greater material elasticity. It also has a higher temperature rating of up to 325°C. FFKM has a nearly universal chemical compatibility, making it an ideal choice for challenging applications.

Advantages of a Perfluoroelastomer

Due to its superior inert properties, FFKM resists volume swell when exposed to more than 1,800 chemicals, solvents and plasmas. FFKM can also withstand the harshest conditions, including those found in medical applications where aggressive agents and steam are used for sterilization and semiconductor manufacturing where oxygen plasma is present.

Because of those advantages, FFKM parts are a viable choice for chemical processing, aerospace, oil and gas exploration, paint and ink production, water and irrigation, life science, medical, and food manufacturing and processing applications.

FKM & FFKM Elastomers Available at Humphrey Products

Humphrey Products has offered FKM as a temperature and chemical compatibility sealing option on their industrial and specialty valves for many years. 

Today, Humphrey offers an FFKM diaphragm option for our 350 Series 2-port and 370 Series 3-port iDP aggressive media solenoid valves. We’ve paired the FFKM diaphragm option with our inert Radel® body material to ensure our iDP valves can safely control the most difficult liquid and gas media, including reagents, chemicals, cleaners, and even steam.

Trust the long-term, proven performance of FFKM parts to reduce the frequency of seal changes, lower inspection and repair costs, improve equipment uptime and increase productivity and yield.

For more information, contact Humphrey Products online or call 1.800.477.8707.

Learn About Our ProControl Proportional Solenoid Valves

Humphrey ProControl Proportional Solenoid Valves offer a wide variety of pressure opportunities for pneumatic applications. These proportional solenoid valves deliver variable control of compressed air or inert gases based on the corresponding input current to the coil.

Types of Proportional Solenoid Valves

Humphrey offers five different types of flow capacity:

  • Mini PV3 and PV10 solenoid valves: These valves offer precise control in confined spaces, cost-effectively. They deliver 0-32 and 0-75 LPM, respectively.
  • PC30 solenoid valves: Mid-size valves with additional flow capacity ranging from 0-225 LPM.
  • Servoid series: These valves are extremely precise and are excellent for various low-pressure settings. They deliver 0-200 LPM.
  • Balanced servoid: Stable performance regardless of upstream pressure changes. This solenoid valve is the industry standard for biomedical critical care patient ventilators.

Control Output Flow Options

Proportional solenoid valves can be used in medical, analytical, instrumentation, test, measurement, factory automation and process control applications.

These valves come with three types of flow options:

  • Selectable: Delivers unique output flow within each cycle.
  • Incremental: Adjusts flow at a predetermined amount within each cycle.
  • Dynamic: Responds continuously to downstream demands.

Proportional Valve Driver

Proportional valve drivers are intended for valves that run on one amp or less, regardless of the valve manufacturer. You can conveniently test, evaluate and use proportional valves with a proportional valve driver in real-time.

Check out our video breakdown for more information. Contact us to learn more about our products.

Breaking Down Proportional Solenoid Valves

Humphrey ProControl™ Proportional Solenoid Valves are an excellent option for pneumatic applications that require variable or controlled valve output flow.

Proportional Solenoid Valves - How They Work

Proportional valves are small two-port, normally closed, direct-acting solenoid valves. They respond precisely to the amount of input current applied to its solenoid. From a stabilized upstream pressure source, customers can expect precise and consistent variable output flow performance for millions of cycles. Output flow adjusts precisely to minor changes in input current.

Proportional valves can enhance pneumatic system performance with soft starts, precision stops, and reduced shock during operation. In closed-loop systems, proportional valves will deliver precise flow control and instantaneous response, even with minute adjustments from input sensors.

The ProControl™ Offering

Today, Humphrey offers three standard valve models and two customizable valve platforms from our Engineered Solutions group. Standard models:

Modifications to standard valves are possible and welcomed. Humphrey can optimize valve performance with an understanding of OEM customer requirements. Contact

The ProControl™ Servoid Series are tailored to specific customer requirements. Featuring very high flow from a low supply pressure source, the Servoid Series can deliver extremely precise and linear output flow with low hysteresis and high-resolution characteristics.

Proportional Solenoid Valve Drivers

Most OEM customers drive proportional valves from their onboard PCB. For others, Valve Drivers are available and are used to take input signals sourced from sensors and deliver appropriate output current to operate the solenoid. Customers use drivers to test, evaluate and use proportional valves on benchtops or in proportional valve projects. Humphrey offers it’s driver with the ProControl™ PCD.

Advantages of Proportional Solenoid Valves

  • Consistent operation without voltage changes
  • Tight seal at rest
  • Low hysteresis
  • Low power consumption
  • Excellent resolution
  • Compact construction

Check out our video breakdown for more information. Contact us to learn more about our products.

Choosing the Right Solenoid Valve for Your Application

There are plenty of variables to consider when selecting a solenoid valve for your fluid control application. Let’s take a look at some of the factors that come into play, and we’ll help narrow your search.

What does the solenoid valve need to accomplish?

Always begin with the valve “need”. What will the solenoid valve do in the application, both in the unactuated, at-rest state, and the actuated, coil-energized, state?  Examples:

  • Control an air cylinder (4-way valve)
  • Start or stop flow only (2-way)
  • Pilot a process valve (3-way)
  • Deliver variable flow (proportional) 

Determine what you need to do and what the timing requirements are. 

What media will the solenoid valve manage?

Your system’s pressurized fluid, whether gas or liquid, is another component to consider when determining the right valve for your application. Secondly, determine the expected minimum & maximum system pressure. It’s essential to find a valve design composition that will perform over an expected cycle life.  

The media’s chemical properties and temperature will dictate the valve’s compatibility. Incompatible valve materials will react to the media, degrade and fail prematurely. Degradation can be gradual, reducing cycle life, and requiring increased preventative maintenance or unexpected repairs.

Will there be more than one media for the application? Consider things like cleaning/flushing fluids, or the possibility of poor or water-ladened compressed air. Always plan for the most challenging media.

What size solenoid valve does the application require?

Properly sizing the flow capacity of the valve is next. Many manufacturers publish a flow rating (LPM, CFM, GPM) at the valve’s maximum pressure specification. Selecting an insufficiently sized valve will degrade system performance, or extend cycle times. It’s crucial to select a valve that can exceed the flow rate of your application, and when a minimum system pressure may exist.  Manufacturers usually provide an industry-accepted flow coefficient (Cv, Kv) that can be used to compare valve brands.

What operating conditions will the solenoid valve face?

Not all solenoid valves are used with clean dry compressed air, controlled precisely to 50 psig and within air conditioned, pristine work environments. Consider more than the most ideal conditions, and specify the valve around those parameters. This includes pressure fluctuations, quality of the media, temperature extremes and work environments.

Consider valve cycle rates and energized times to be expected of the valve, as performance and life of some brands can be affected. And finally, all valves can leak (extremely small amounts) of the media some brands more than others particularly as the valve wears over time. Take reasonable precautions and anticipate valve leakage.

A reliable valve manufacturing partner will help you find the right solenoid valve for any application. Call 800-477-8707 or contact Humphrey Products online, and we’ll get you started.

Valves 101 | Basic Pneumatics

Pneumatic Pressure Control and Flow Control Valves

Pressure control is the control of a fluid’s force within a vessel. It is transmitted equally in all directions. Think of your automobile’s tire pressure. When the pressure in all four tires is set properly, they collectively exert enough force (power) within them to safely support your automobile.

Flow control is controlling the movement of pressure between two vessels, and it moves from the vessel with greater pressure to the vessel with lower pressure. When tire pressure is too high, the tire valve is opened to release pressure from the tire “flowing” to the atmosphere. When tire pressure is too low, the valve is opened to receive a greater pressure “flowing” from the air compressor. 

Today, electronic sensor technology exists such that pressure and flow can be changed dynamically, in a closed-looped microprocessor-based system. A simple example is a service station tire pump, which allows you to set your desired tire pressure and automatically shuts off the pump when that pressure setting is achieved.

Pneumatic Flow Control Valves

All valves control flow. The industry term "flow control valve" refers to its ability to vary the flow of a fixed pressure to its output side. There are manually controlled and current (amperage) controlled valve types.

Manual flow control valves usually have a knurled adjustment knob or throttle. Once the desired flow is set, these valves remain in that flow setting until further adjusted. 

Flow control valves (operated by current) are commonly referred to as proportional valves. As amperage is applied or varied to its solenoid operator, the output flow of the valve varies accordingly. 

The primary advantage of these “proportional valves” is their ability to be used with a microprocessor-based programmable controller, particularly in closed-loop systems. In these systems, downstream sensors continuously provide feedback to the controller to change (or not) the current to the valve’s solenoid operator.

Other names for flow control valves include:

  • Needle valves
  • Proportional valves
  • Meter out valves

Pneumatic Pressure Control Valves

Pneumatic pressure control valves are commonly called pressure regulators and come in manual and electronic models, similar to flow control valves. Pressure regulators are designed to respond and maintain a controlled downstream pressure setting when a pressure loss or surge occurs. Each pressure regulator has a restriction, load and reference element to respond to pressure and maintain the desired output.

They are only used in closed-loop systems since they require downstream feedback to maintain a set pressure. Pressure regulators are offered with either piston or diaphragm-type valves. Piston types are better suited to rugged applications that require some accuracy and durability, while diaphragms provide precision control.

Pneumatic Flow Control Valves & Pressure Control Valves From Humphrey Products

Contact Humphrey Products online or call 800-477-8707 to learn more about our customizable valve solutions for fluid handling and pneumatic systems. 

pressure control and flow control
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