At our 100,000-square-foot facility in Euclid, Ohio, we stock a large number of components, everything from MHC governor stands to Rexroth® actuators to servos and solenoid valves.

We also take a lot of pride in our repair documentation. In addition to recording the model and serial number, we note any auxiliary equipment like a servo solenoid, which most of the actuators have, before we start the disassembly process.

GE® and Toshiba® both use Rexroth® actuators on their combined cycle units. Toshiba® mounts their actuators in a horizontal position, while, GE® mounts them vertically. That difference can cause a maintenance problem.

Mounting the actuator in a horizontal position causes a lot of stress on the shaft. As the actuator control valve strokes back and forth, it puts a tremendous amount of weight on the seal. All that weight sits on the down side of the spring can retainer. So as the actuator strokes to regulate the speed of the turbine, it causes a lot of stress.

One customer has a large Toshiba® steam turbine that uses these valves and gets about two years out of them before the stress wears away the seal. Then metal-to-metal contact occurs between the ID of the spring can and the OD of the spring can retainer. That causes drag and friction and also lowers the shaft.

As the shaft lowers and the friction increases, the forces put more stress on the guide bushing that’s closest to the spring can. Those seals start to wear away and the equipment may leak fluid into the spring can.

Our technicians have worked on different actuators for different Toshiba® units from large steam turbines to combined cycle units. All examples had the same scoring and the same wear on the lower side of the spring can where the spring can retainer and the spring can meet.

MD&A experts created an actuator upgrade for horizontal mounted actuators where we coat the inside of the spring can, upgrade the seal, and redesign the HP bushing & the LP bushing.

With those modifications, we expect to extend the life of the Rexroth® actuator on the Toshiba® units so that they need service no more than once every four years, roughly doubling the current outage interval.

MD&A Bearings, Seals & Hydraulics division, since 1984, has refurbished and upgraded hydraulic control components, such as actuators.  We can offer a short cycle turnaround because of our inventory of components, along with our team’s knowledge.

Call our MD&A Bearings, Seals & Hydraulics division today at (800) 446-4776 or use our Contact form.

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We maintain a large inventory of Rexroth® hydraulic servos, solenoids, rebuild kits and disc springs to satisfy short-cycle turnaround requirements. To date, MD&A has inspected & repaired 300+ Rexroth® actuators.

View the video to see how we can meet your Rexroth® actuator short-cycle turnaround requirements. For additional information call MD&A’s Bearings, Seals & Hydraulics Division today at (440) 946-0082 or use our Contact form.

MD&A is committed to serving the needs of combined cycle plant owners.

We provide complete refurbishment of Rexroth® hydraulic actuators.

EHC & MHC Systems are a major contributor to forced outages throughout the Power Generation Industry.

MD&A’s Bearings, Seals & Hydraulics division has been troubleshooting and overhauling utility EHC and MHC components for more than 15 years.

Upon arrival, we inspect and disassemble the actuator revealing any problems or damaged components, along with draining all the fluids.

We photograph and document all components upon incoming inspection.

A unique stand for the actuators holds it in place while we depressurize the actuator with the disc springs inside.

A large inventory of Rexroth® hydraulic servos, solenoids, rebuild kits and disc springs is maintained to satisfy short-cycle turnaround requirements.

Documented functional testing of your actuator assures a seamless transition to system operations.

The first step in the testing process is to flush the actuator.

After flushing, the system is tested at the MD&A shop using the same type of hydraulic fluid that is used at the owners’ site.

The testing of all hydraulic control components repaired at MD&A greatly reduces the need for field adjustment during start-up.

MD&A provides shipping stands and containers for secure inbound and outbound transit.

MD&A offers short cycle turnaround for customers who encounter emergencies and need components repaired and returned as soon as possible.

See our case study example here.

Notice: Rexroth is a trademark of Bosch Rexroth AG® MD&A is not affiliated with or endorsed by Bosch Rexroth AG.

The post <em><strong>Rexroth</strong></em> Actuators Rebuild appeared first on MDA Turbines.

During operation the owner observed erratic valve response and hydraulic fluid weeping from a telltale drain. The disassembly discovery revealed fractured disc springs and embrittled seals in the packing head and cylinder. The servo and poppet valves were damaged due to fluid contamination.

Shaft scoring and spring housing gaulling was also observed as a result of the above mentioned discovery.

Upon reassemble with new components, the Rexroth® actuator was functionally tested in a test stand at the MD&A shop using the exact same brand of EH fluid that is used at the owners’ site. MD&A provided shipping stands and containers for secure inbound / outbound transit.

SUMMARY

MD&A is committed to supporting combined cycle plant owners’ Rexroth® hydraulic actuators needs.

MD&A understands the urgency of downtime and will conduct a proactive survey of your hydraulic actuators to assure they have the parts on hand to support a quick turnaround.

To schedule a survey of your Rexroth® Hydraulic Actuators, call MD&A at (800) 446-4776.

Learn more about the other Gas Turbine Services that MD&A offers

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