Gas turbine inspection and refurbishment services
KEMA provides impartial gas turbine and generator honing and boresonic examinations and hot gas path, blades and coating inspections and refurbishment consultancy
Turbine and generator honing and boresonic examinations
Driven by the need to better define operational reliability of power generation equipment, boresonics has now become a fairly common and accepted practice within the rank and file of the utility industry. In general, boresonics involves the transportation of ultrasonic transducers through the rotor bore so as to search a given volume of material for flaws at different locations and orientations within a rotor forging. Boresonic inspection of steam turbine rotors primarily deals with the near bore region of the spindle forging. The central region of large ingot castings have contained the highest density of internal flaws.
Gas turbine blades inspection in a closed housing
Gas turbines can be fully opened for inspections. However, it is often possible to save the expense of disassembling the housing as well as the power outage time. Therefore, inspection holes are commonly integrated into the gas turbine housing. Once smaller linear flaw indications in blades or vanes are detected the discussion arises like:
- Is this something trivial?
- Is it a crack in the base material?
- Should we open the housing and find nothing?
- Should we continue operation and bare the risk?
The VINSPEC system enables us to provide you with the right answers. The inspection is conducted through the inspection holes (> 6 mm).
Gas turbine rotor inspection and FfP assessment
Gas turbine rotors may be susceptible to life limitations due to creep and/or fatigue. This may lead to critical cracking and catastrophic failure. Assessment of critical areas is necessary to determine opportunities for continued operation. KEMA offers this Fitness-for-Purpose assessment and non-destructive inspection of rotors with high reliability and at low cost.
Coating condition assessment of gas turbine blades
Sophisticated coatings protect the super alloys in your turbines against oxidation, corrosion and environmentally unfriendly components. Non-destructive evaluation of both new and in-service high-temperature coatings on gas turbine blades is an important factor in achieving a high level of structural integrity in advanced gas turbines. Multi-frequency-scanning eddy current techniques are able to determine the coating thickness as well as the aluminum content of the coating. Therefore they can be used as a quality assurance tool upon acceptance of the blades. KEMA offers this technique as COCOM (COating COndition Measurement), a system to assess the condition of gas turbine blade coatings. Experimentally, the method relies on eddy current measurements.
Refurbishment of hot gas path components
Gas turbine hot gas path components have finite life. Therefore, operators face component replacement on a regular bases. Decisions have to be made on whether these components are to be replaced by new components (original or reverse engineered) or whether the condition of the component can be restored by a repair or refurbishment procedure.
Due to the high costs associated with purchasing new components, many repair shops offer reverse engineering for gas turbine components. The price difference is often significant but, what about the risks? No one can rule out all accidents at an affordable price but one can use the expert’s knowledge to look over the shoulder and to ask the relevant questions. Just copying the components and getting round all patent claims does not necessarily mean that the new components will stand the job! Assistance of an independent expert to pinpoint the relevant bottlenecks will enable you to manage the costs and timetable the reverse engineering project.
KEMA provides impartial advice on the classification of parts to assure that components are not unnecessarily scrapped or repaired beyond allowable material degradation constraints. Acting as the clients technical representative KEMA provides the following services:
- repair shop production process and quality system audit
- quantitative condition determination
- writing a request for tender, including all technical specifications
- bid evaluation and contract negotiation support
- quality control of the refurbishment activities at the OEM or specialized repair companies.
Not only non-compliances are detected and reported, we also advice on the effect of the non-compliance on the technical integrity and expected component lifetime.