How to carry out preventive maintenance on mechanical pumps?

Yeah, I’ve been to many large companies. It’s rarely done there, as pump systems usually operate with one unit in use and another as a backup; in case of a failure, the backup pump can be started. Therefore, preventive maintenance is less common for mechanical pumps. For large companies such as CNPC and Sinopec, during regular major overhauls of the facilities, it is possible to consider disassembling and inspecting important mechanical pumps, even if they are not faulty, as a form of preventive maintenance

As a maintenance strategy, preventive maintenance was an effective approach in the past when there were no adequate monitoring tools available; however, it was not cost-effective. Nowadays, with the use of monitoring equipment, maintenance is carried out on a as-needed basis, which helps to maintain production while reducing maintenance costs

Oh, preventive maintenance generally refers to the regular inspection of key components of the equipment or the replacement of certain parts at intervals specified in the manufacturer’s manual; for example, the mechanical seal is replaced once 16,000 operating hours have been reached. In countries such as Canada, I have seen that typical factories assign a reliability engineer who monitors the operating conditions of the equipment on a regular basis. This includes keeping an eye on changes in process parameters, vibration levels, the temperature of the lubricating oil, as well as the results of analyses of the lubricating oil itself, including changes in various trace elements and viscosity. By doing so, it is possible to extend the maintenance or replacement intervals specified in the manufacturer’s manuals. What I am currently researching is a branch of this reliability technology, namely vibration analysis.

Everyone here is an expert. I work in a private company, where I am in charge of everything – equipment, instruments, manufacturing processes, procurement, and electrical systems. We’re not as professional as you are, but when working with equipment, we usually conduct inspections and stop the pump immediately if any abnormalities are detected to investigate them. Based on the equipment’s operating time, as well as the instructions and production conditions, a check of the bearings and shaft sleeves will be carried out every few years. Since we are shielded pumps, their maintenance is relatively simple. For ordinary, unimportant pumps, maintenance is generally carried out only after abnormalities are detected. Do not perform protective checks

It’s basically RCM, but our current project in Canada is still quite small, so we can’t use RCM. I estimate that in a few years, once our company’s business has grown stronger, we will have such a system in place. I am currently studying materials on *vibration, in preparation for attending a Mobis training session in November and taking the CAT II exam; I plan to take the CAT III exam in March next year.

Could you recommend some materials on this topic? I’d like to learn about it too

\"Practical Techniques for Simple Vibration Diagnosis on Site\": Understanding this book is considered a basic starting point. Based on my experience in this field over the past year or so, while some results have been achieved, I am rather pessimistic about predictive maintenance – it is useful, but there are too many factors at play, making it difficult to implement effectively. Current technologies require high levels of knowledge, expertise, and experience from those who carry out monitoring tasks, which makes widespread adoption challenging. I hope this can be helpful to you.

For preventive maintenance, personal advice is to follow the requirements outlined in the maintenance documents. Referring to it based on the equipment’s condition is a vague approach; without the means or expertise to determine the actual condition, it’s essentially the same as saying nothing at all.

That’s right. On one hand, there is specialized technical knowledge; on the other hand, knowledge of diagnosis as well as management skills are also required

For preventive maintenance of mechanical pumps, the focus is on mechanical seals. According to the API682 standard for mechanical seals, their service life is 25,000 hours, which is equivalent to three years. However, for more than half of these seals, due to factors such as operating conditions and usage patterns, a service life of two years is already considered quite good. Therefore, it is necessary to determine an appropriate maintenance schedule based on the actual service life of the mechanical seals in use. In our company, mechanical seals are generally replaced compulsorily after two years； For bearings, they are generally replaced based on monitoring results, but for individual pieces of equipment that have a significant impact on the system, preventive maintenance is the best approach.