835 Industrial Hwy | Cinnaminson, NJ 08077

Series DAO

Full Round Port
Mechanically Pinched
Dual Pinch Mechanism
Most Economical Mechanical Design
Open Frame Design
Low to Moderate Pressures

  • Available in Full Round or Pre-Pinched construction.
  • Light weight
  • Low pressure drop
  • Drop tight closure
  • On/Off or throttling service
  • Fail Open or Fail Closed pneumatic actuators

Warnings: Warning ! Open frame valves have no provision for containing process fluid during a sleeve failure. Fluid may erupt unexpectedly from the valve. Do not use an open frame valve for fluids that are hot, acidic, flammable or toxic. Otherwise, serious injury may result.


  • Flanges: ANSI STD 125/150 lbs
  • Stem & Guide rods: 303 stainless steel


  • Epoxy paint
  • Sleeve elastomer
  • Valve length
  • 316 stainless steel stem
  • Positioners
  • Solenoid valves
  • Limit switches

Valve Sizes:

Actuator Sizes:

Actuator Selection Information

Click to review options
Double Acting Cylinder PFO - Pneumatic Fall Open PFC - Pneumatic Fall Closed
All mechanically pinched pneumatic valves are available with 2 families of pneumatic actuator:
  1. A conventional air double acting cylinder. Air is applied alternating to the cylinder head and cylinder bottom to open and close the valve. This is inherently a Fail-in-last-position actuator.
  2. Onyx "Bomb Proof" zero maintenance actuator. This actuator is designed around a firestone airbag for the most robust construction and zero maintenance. It is available in two configurations:
A.PFO-Pneumatic Fail Open B.PFC-Pneumatic Fail Closed-Fails closed with a spring for the most dependable drop tight operation. All actuator sizing is performed by Onyx Engineers based on three factors:
  1. Valve Size
  2. Fail Mode
  3. Process Pressure
Consult the factory for assistance in specialty actuator size selection. Fill out the contact form at the bottom of this page with pertinent information and an Onyx Representative will be in contact with you shortly.

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