RTO Rotary Valve Drive Upgrade: Pneumatic to Electric

RTO Rotary Valve Drive Upgrade: Pneumatic to Electric

Case Study: Kono Kogs removed an RTO's pneumatic valve drive, then designed, fabricated & installed an electric drive assembly to reduce risk of downtime.

Type of Work:
Equipment & Installation
Type of Equipment:
Regenerative Thermal Oxidizer (RTO)


Pneumatic driven rotary valves on regenerative thermal oxidizers (RTO) have been proven over the past 20+ years, but they do experience significant wear.  The wear is due to the violence of stopping the large-mass valve rotor at the end of travel. Rack and pinion designs work well for these rotary designs, but the cushions at end of travel wear out. If not properly maintained, this leads to other more serious part failures and RTO shutdowns. Pneumatic driven rotary valves require diligent maintenance and inspections to avoid both nuisance and long-term maintenance shutdowns. There are also the typical problems with utilizing pneumatics in RTOs located outdoors due to the risk of moisture/ice forming in the air lines during cold/freezing weather.

This 25,000 scfm capacity Durr Reeco RL RTO had a drive air cylinder and a pinning air cylinder each with its own solenoid actuating valve. These parts are not always readily available which puts the RTO at risk of extended downtime and production schedule upsets.

Photos: In Progess

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Kono Kogs was chosen to retrofit this electric valve drive upgrade to address the recurring issues experienced with the pneumatic valve drive design. An electric driven rotary switching valve was designed, fabricated and installed in this regenerative thermal oxidizer (RTO). The new electric rotary valve drive included a new rack, a gear box, and variable speed drive, and PLC control logic.

Photos: After

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Equipment & Services Provided

  • Remove pneumatic valve drive
  • Design, fabricate & install electric drive assembly
  • Update PLC controls/Logic for drive control addition
  • Equipment restart
Regenerative Thermal Oxidizer (RTO)


The electric valve drive on this RTO and many others have been field proven over thousands of operating hours. If you have wear issues on your current rotary valve drive or freezing pneumatic lines during winter weather, give us a call for a retrofit quote. We have now retrofit this valve upgrade on several Durr-Reeco RL RTOS and MEGTEC Clean Switch RTOs.

See more examples of our custom design and fabrication work.

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