Conversion of an O Series Pneumatic Actuator Fail Position

This video shows the conversion of the O Series Pneumatic Actuator fail position from fail closed to fail open.

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In this video we will be converting an O Series fail closed pneumatic actuator to fail open.

First remove the indicator cap from the top of the actuator.
Please note that the slot in the shaft is perpendicular tho the actuator housing.

O Seris Pneumatic Actuator

O Series Pneumatic Actuator

Remove spring end caps. This is the actuator with the end caps fully removed.

To remove the internal pistons, place a wrench on the actuator stem and rotate counterclockwise until the pistons can be pulled out.  It is very important to note the orientation of the pistons as they come out of the actuators, since you will rotate them 180°.

Here is a side view showing how the piston was removed and how it engaged the internal yoke. The bar on the piston (A) engages with the notch in the yoke(B).

The shaft needs to be rotated so the piston engages on the opposite side. Use a wrench to rotate the shaft counterclockwise approximately 90 degrees.

After the pistons are rotated 180 degrees , push them into the actuator to engage with the yoke.  Rotate the shaft counterclockwise until the pistons are pulled fully into the actuator housing.
Note the slot on the shaft should now be parallel to the actuator housing.

Re-attach the spring end caps but be sure to match the tabbed o-ring to mate with the air port on the actuator housing.  Tighten end caps.  Attach indicator cap.

The actuator should rotate clockwise when air is applied. It should spring closed counter clockwise when air is removed.

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About Kim O'Neill

Marketing administrator at Assured Automation, a leading provider of automated valves and flow components for industrial process control applications. For over 30 years Assured Automation has provided state of the art automation to a diverse clientele ranging from small equipment manufacturers to Fortune 500 Manufacturing, Chemical and Pharmaceutical companies. The Assured Automation product line consists of a complete offering of standardized automated valve assemblies with a variety of commonly used accessory items. In addition, we offer complete valve automation services where we supply special automated valve assemblies designed around your specified products or your particular applications. Full design capabilities are offered including AutoCAD, Solidworks or other commonly used design and drawing programs. In addition to standard products, Assured Automation develops customized solutions for specific customer challenges. You can find Kim O'Neill on LinkedIn.
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