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ProControl™ Valve Series

Delivers Precise Variable Flow Control

Proportional Control Solenoid Valves deliver variable output flow control from corresponding input current to its solenoid. The compact design of Humphrey’s ProControl™ Series is an excellent addition to any device or equipment and offers flexibility, precise control of flow, and economic advantages not available from on/off solenoid valves.

Humphrey ProControl™ proportional valves are available in five sizes and feature:

  • Low hysteresis
  • Excellent turndown ratios (resolution)
  • Cycle repeatability

The advanced ProControl™ Servoid Series delivers extremely precise control and high output flow settings, and has become a standard in critical care patient ventilation equipment. 

Use ProControl™ Valves to control flow:

  • Dynamically: for continuous high-frequency adjustments (closed-loop responses)
  • Incrementally: with pre-determined low-frequency adjustments within each cycle
  • Selectable: cycle-to-cycle selected output flow, as prescribed

Technical Assistance

Humphrey offers Proportional Valve Application & Selection assistance to ensure you achieve the best results. Call 844-447-9009 or email

PV3 0-30 SLPM 2.4 watt 25 (1.7), 50 (3.4), 75 (5.2), 100 (6.9)
PV10 0-75 SLPM 4.8 watt 25 (1.7), 50 (3.4), 75 (5.2), 100 (6.9)
PC30 0-225 SLPM 8.3 watt 25 (1.7), 50 (3.4), 100 (6.9)
Servoid 0-200 SLPM 15 watt Custom to 30 (2)
Balanced Servoid* 0-200 SLPM 8 watt Custom to 11 (.75)
iDP 390 & 391 0-80 SLPM (Air) or
0-1.5 SLPM (Water)
8.3 watt 10 (0.68), 20 (1.37), 40 (2.75)
* Consult factory for higher pressure and flow options.

Miniature Proportional Solenoid Valves

Humphrey’s PV3 and PV10 series of miniature solenoid valves deliver variable flow control of compressed air or inert gas. The 10-32 UNF ported PV3 and PV10 are available as inline or subbase mounts with low hysteresis, excellent resolution and cycle repeatability.

View Miniature Proportional Solenoid Valves
Miniature Proportional Solenoid Valves

Small Proportional Solenoid Valves

The 1/4 NPSF PC30 ProControl™ proportional solenoid valves deliver variable flow control of compressed air or inert gas from an input current. The rugged, compact PC30 series is flexible and may be customized with unique requirements for specific applications.


  • Low hysteresis
  • Excellent resolution
  • Inline or subbase mount
  • High flow up to 225 SLPM
View Small Proportional Solenoid Vavles
Small Proportional Solenoid Valves


Large Proportional Solenoid Valves – Servoid Series

Balanced Servoid and Unbalanced Servoid Series proportional valves provide superior pressure and flow control performance of inert gases. ProControl Servoid ™ utilizes a frictionless, flat-spring armature cartridge to achieve excellent characteristics and long life with a compact construction. With this superior design, we recommend our factory assistance to calibrate Servoid Series valves to your precise requirements.

Balanced servoids offer:

  • Stable performance regardless of upstream pressure fluctuations
  • Ultra-low hysteresis and excellent turndown ratios
  • Precise flow rates of up to 200 SLPM at 11 PSI
  • Single solenoid, normally closed 2-port valve function

Unbalanced servoids specs include:

  • High flow design
  • Low hysteresis and excellent turndown ratios
  • Excellent repeatability
  • A flow rate of 170 SLPM at 1.7 PSI
View Large Proportional Solenoid Valves
large proportional solenoid valves


Proportional Solenoid Valve Driver

Consider the convenient Humphrey PCD Proportional Valve Driver for valve testing or workbench use. ProControl™ PCD produces appropriate current control and power supply hook-up to drive any proportional valve of 1 amp or less either manually or from a signal from any data acquisition source. Additionally, drive proportional valves through PWM or constant current signals with PCD. 


  • Control input options: 0 to 5v, 0 to 10v, 4-20mA, or manual 
  • Presets for Humphrey ProControl Valve models: PV3, PV10, PC30, or Servoid models, 
  • Connector: screwless, push-button clamp 
  • User interface: LCD Screen 
  • Industry-leading LCD readout 
  • Setup/installation instructions included
View Proportional Solenoid Valve Driver
Proportional Solenoid Valve Driver

Check out our ProControl™ Series video:



  • Proportional Control Valves
  • Proportional Valves
  • Miniature Proportional Valves
  • Electronic Flow Control Valves
  • Electronic Flow Controllers
  • Analog Flow Control Valves
  • Solenoid Flow Controllers