In the past four years, a client had experienced problems with the operation of his plant that was caused by an air entry into the vacuum system. As a result, the efficiency of the plant was worse. For example, more energy was needed to achieve the result, which meant that more pumps were used. In the past four years, other parties had carried out various measurements and techniques to find out the cause of the problem, with no answer.
In 2019, the client approached Applus+ to help think about a solution. A team of two inspectors travelled to the customer location in Asia. After just half a day of testing, the cause of their problem was found, much to the relief of the customer.
Thanks to checking the vacuum system using a helium leak test and testing the cooler bank, which was a challenge due to inaccessibility and the heat, the leak test specialists examined the cooler bank installation with an infrared camera. Soon after the start of the measurement, large leaks were found on the internal labyrinth seal of the turbine.
To show that the leaks were the problem. The inspectors had provisionally repaired the leak and the value of the vacuum pressure rise test was significantly better after the repair. During subsequent testing it appeared that the leakage spread to other parts of the labyrinth system. It became clear that a more extensive and comprehensive repair of the labyrinth system is needed. As soon as the plant is taken out of service for maintenance, this will be resolved.
The client was sceptical in the beginning about our measurements, because different local parties had already carried out this in the past. Fortunately, there were a number of references that helped convince the customer of the quality of Applus+.
Thanks to the experience and knowledge of our specialists and the use of the right equipment, the inspectors were able to find the cause of the problem and advise the customer about a solution. Subsequent discussions with the client confirmed that we had provided the solution and the leaks were traced. Applus+ has advised the customer about which repairs need to be carried out to guarantee the reliability of the turbine.