Maintenance Best Practices

This issue delves deeply into various turbomachinery best practices. One article lays out the intricacies of how to install a hydraulic hub on a rotor. There is a lot more to this than meets the eye, and unfortunately it is done incorrectly too many times.

Another story is all about lubrication best practices concerning various types of monitoring, as well as the fine points of lubrication for rolling element bearings. Bearing troubles have been found to account for around 50% to 70% of all failures associated with small and medium size turbomachinery using rolling-element bearings. Poor lubrication practices account for most of these troubles. Some estimates are that more than 50% of all bearing failures are related to lubrication. Good maintenance procedures, planning, and the use of the correct lubrication oil can improve overall operation and reliability.

Our cover shot is a laser scan of turbomachinery, a practice that is gaining ground in the industry. As-built data and models are often inaccurate. During construction, contractors and engineers modify and correct on the fly to solve problems. The original design drawings and 3D models are rarely updated to reflect these adjustments. Laser scanning offers a fast and effective way to update as-built records. It can cover a much larger area, is more complete, and is more accurate than traditional methods. A study carried out by DuPont concluded that laser scanning should be used on every revamp and retrofit project regardless of size.

Control systems, too, require attention and upgrades. Artificial intelligence (AI) is now being incorporated into the latest systems as digitization gathers steam. It offers a way to put data to more productive use. But the design of the system and its associated architecture must be correct. One way to do it is to institute edge computing so data can be processed and analyzed locally. This reduces the burden on computers and networks as only the most relevant information is sent to the plant’s central control system. This is just one way that AI is being incorporated into modern plants.

And then there are coupling bolts. Like hydraulic hubs, there is plenty to know on the subject. This article describes how to avoid the various issues associated with seized coupling bolts. Misalignment in steam turbines, for example, causes vibration, puts unnecessary load on bearings, and curtails operation at full power. High energy tools are needed for such maintenance work. The bolts must be closely fitted or interference-fitted with their mating coupling bores to transfer the proper torque.

The maintenance theme is continued in our annual report from the 2018 Turbomachinery Symposium. This year, the event addressed problems, such as compressor fouling, mechanical seal failure, impeller inefficiency, nitrogen compression, and piping vibration.

But there comes a point where maintenance ends and new construction becomes essential. Our lead news story showcases three new plants built in Egypt in just over two years. At 4,800 MW each, they can all claim to be the largest combined cycle plant in the world. Siemens provided the equipment and technical guidance, working with local EPC firms and the Egyptian government on a fast track basis. Such projects serve to highlight the value of natural gas-based power plants on the world stage.

With the end of the year approaching, our next stop is the annual PowerGen International show, this year in Orlando. We look forward to seeing you there. Wishing you a Happy Holiday Season.