The benefits of midlife MOV overhaul

If the typical electric actuator is expected to provide 20-25 years of reliable operation, sites that use MOVs in their business operations might want to consider the benefits of overhauling these assets to manage risk effectively. But what does this entail – and what are the typical costs to compare against the losses from an unplanned outage or the asset reaching its End-of-Life prematurely and putting a strain on CAPEX plans?

In my experience, most electric actuators performing average duty are satisfied with one mid-life overhaul somewhere around the 10 year mark. This is especially important for those that have not received regular PM attention since original install. Use this opportunity to replace the soft components which have exceeded their usable lifespan and catch any deficiency which has yet to be flagged externally. MOVs operating in severe environments could require a more frequent schedule.

Overhaul should allow for complete disassembly & component inspection - as there is a limit to the extent of work possible with the actuator attached to the valve in situ. At a minimum – all elastomeric oil seals and o-rings are replaced with new. New circlips, minor springs & fasteners, roller and thrust bearings. All major components (power module, center column, PCBs, torque sensors etc) inspected and replaced as needed. Fresh oil. Complete calibration on torque bench to ensure output and motor amp draws are within factory design tolerances.  Full documentation and 1 year warranty covering items replaced. Commissioned back into service onsite by qualified Rotork technicians.

The cost to overhaul can average 25-33% the price of new if no major components require replacement. This small investment could make the difference between your actuator reaching its full operating potential.... or making an early exit.

Contact the author to help your Maintenance / Reliability teams assess MOV equipment risk and develop a customized plan which secures your operational goals.