Thermally compensated, 2-way normally closed (NC) proportional valve designed for flows up to 40 slpm. Ideal for respiratory and patient monitoring applications that require precise pressure and flow control.

Product Information

The VSO®- MI is a miniature proportional valve designed for medical equipment manufacturers. Based upon Parker Hannifin’s benchmark VSO® design, the VSO®- MI miniature proportional valve incorporates thermal compensation to provide precise flow control and stability over a wide range of media. Unlike competitive valves in its class, the VSO®- MI miniature proportional valve has been tested to U.S. Pharmacopoeia (USP) Class VI requirements making it easier to achieve system compliance for toxicity and sensitivity. With integrated filtration, captive O-rings, flush manifold mount capability, low power consumption and light weight, the VSO®- MI is an efficient miniature proportional valve ideally suited for manufacturers of portable and stationary medical equipment.
  • Thermally compensated to maintain precision flow and accuracy
  • Tested to USP Class VI requirements to ease system compliance
  • Proven performance tested to 25 million life cycles
  • Integrated filters to protect the valve from damaging upstream and downstream particulates
  • Cleaned for Oxygen Service Use
  • RoHS compliant

Typical Applications:

  • Ventilators
  • Oxygen Concentrators
  • Oxygen Conservers
  • Anesthesia Delivery & Monitors
  • Pressure & Flow Control
  • Blood Pressure Monitoring

Technical Specifications

Voltage Configurations Available:5.5 VDC, 13.5 VDC and 29 VDC
Typical Applications:Ventilators, Oxygen Concentrators, Oxygen Conservers, Anesthesia Delivery & Monitors, Pressure & Flow Control and Blood Pressure Monitoring
Orifice Sizes Available:0.031 to 0.51 in. (0.79 and 1.30 mm)
Thermal Compensation:Thermally Compensated
Control Method:Current or Voltage
Cleanliness:Oxygen Use Clean
Valve Configuration(Type):2 Way Normally Closed
Life (# cycles):Up to 25 Million Cycles
Pneumatic Connection Options:Manifold Mount w/Integrated Screens and Seals
Electrical Connection Options:18" Wire Leads, 4 Pin PC Connection, Quick Spade Connection
Leak Rate: Power Consumption (Watts):2.0 Watts Maximum
Weight:1.23 oz (34.9 g)


Flow Rate Range:0 to 40 slpm
Pressure Range:0 to 150 psi


Width:0.66 in (16.7 mm)
Height:0.74 in (18.8 mm)
Length:1.77 in (44.9 mm)

Wetted Materials

Body/Stem Base:PBT, 430 FR Stainless Steel and Brass C3600 HT
All other:300 Series Stainless Steel

Data Sheet

Click to download the Technical Specification of VSO-MI - Miniature Proportional Valve