Steam Turbine Rotor Repairs in Saudi Arabia
As a worldwide company, Mechanical Dynamics and Analysis (MD&A) recently completed on-site the installation of new buckets and covers on a Steam Turbine in Saudi Arabia, alongside conducting diaphragm repairs at our facility.
We were contracted to perform an inspection and any necessary Steam Turbine rotor repairs. After a thorough inspection, bucket and cover repair work was performed on the 1st and 17th stages of this rotor due to damage identified. This rotor has a total of 19 stages, 12 high pressures and 7 reheat stages.
The 1st stage buckets and covers were replaced with hardware supplied by the customer. The new buckets were installed on-site, the notch bucket was driven and pinned and the new covers were peened into placed using gathered reverse engineering data.
The 17th stage had the covers that were found partially liberated. The tenons of those buckets that had liberated covers were welded up, and then new covers installed.
Both stages were machined to restore the proper clearance and required features.
Further inspection of the rotor showed that the underside of the bucket covers on the other stages had excessive debris build up, which was was removed and the entire rotor was then blast cleaned.
1st stage row restoration and machining completed
17th stage cover restoration and machining completed
1st stage admission side machined
Additionally, during the on-site inspection of the turbine first stage stationary blading (diaphragm) severe damage was found and MD&A was requested to repair this diaphragm. The diaphragm was shipped to our Turbine-Generator Repair Facility in St. Louis MO. Upon inspection, it was discovered that the diaphragm exhibited significant Foreign Object Damage (FOD) and linear indications were detected in the partitions.
When the diaphragm was received, it was cleaned and given a complete Non-Destructive Examination. Due to the extent of damage found on the blading in the steam path partitions, major repairs were required. After weld repair was performed, a post weld heat treatment was done to remove residual stresses.
Repair of the partition side wall, as well at the horizontal joint, were necessary due to extensive damage found. The steam seal face was machined, and an insert installed to restore the axial position of this diaphragm.
New diaphragm root radial seals, seal strips and horizontal joint keys were installed as well as the support bars for the diaphragm.
MD&A can be called upon to perform any technical evaluation anywhere and do the work needed for your rotating power generation equipment to get it back online safely and quickly.
Steam seal face prior to insert installation
Extensive damage to the steampath
Final diaphragm repair finished and ready for shipment back to site.Tags:
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