Corporate Industries

Delcam’s PowerINSPECT critical in steam turbine repair

Inspection of the turbine with Delcam’s PowerINSPECT shows the extent of the repair that is needed

Reverse engineering with a Romer/CimCore arm and Delcam’s PowerINSPECT inspection software is a critical part of the steam turbine repair business Hickham Industries. Based in La Porte, Texas, Hickham is the largest and most diverse such facility in North America.

Repairing steam turbines is all about efficiency, quality and precision. Customers in the petrochemical, oil and gas and power-generation businesses may be losing hundreds of thousands of dollars a day if a key piece of machinery is out of action. To add to the challenge, there are almost never any original drawings to go by. Typically, the drawings have been lost. Even when they are available, they may not be very helpful anyway because of modifications, wear and corrosion over the years.

Dave Dixon, Project Manager for the hot-gas expanders business at Hickham, observed, "We have to get the measurements right. The margin for any type of error is very small and the price of an error is extremely high. Data from our reverse engineering efforts support all the key decisions on what repairs are needed, how they will be done, how long it will take, and which parts must be replaced.”

"The likelihood of errors is reduced by using PowerINSPECT,” Project Engineer Jaime Valdez added. "By giving us dimensions that are reliable, the Romer/CimCore arm and PowerINSPECT help ensure that we are making the right decisions.”

Internal diameters of casing seals are the biggest and most awkward surfaces to measure and they are among the most critical. The ends of the blades of the rotating parts run with tight clearances to the casing. If these dimensions are exceeded, the turbine’s efficiency plummets.

In rebuilding casings, often the diaphragm, seal and bearing housing fits on a case are eroded. To repair them, damaged sections must be removed and re-machined in preparation for being built up again with welded metal. The weld is then machined to the final dimensions. "PowerINSPECT helps us establish dimensions to an existing reference point so that we can accurately return the weld repair to "as new” dimensions,” Mr. Valdez said.

"Our machinists then cut these parts to our numbers,” operator Jesse Haver explained. "The accurate measurements mean they no longer have to do trial-and-error machining. All the time-consuming manoeuvring that goes with cut-and-fit machining has been eliminated. We can now do in two days what sometimes took weeks!”

"Another nice thing about PowerINSPECT is that it works well with the plant’s new wireless network,” Mr. Haver added. "After a measuring job, in the time it takes to pack up the Romer/CimCore arm and bring it back to the office, the network has sent the data back to the laptop in the office and formatted the measurements into a formal report. We can see it immediately.”