pdf Troubleshooting Centrifugal Pump Field Problems (English Edition)

Centrifugal pumps are the most common type of process pump in use today. They are frequently the pump design of choice due to their design simplicity, high efficiency, wide range of available flow and head designs, smooth flow performance, and ease of operation and maintenance. Their widespread use is a testament to their cost effectiveness and mechanical reliability. In most applications, they provide years of reliable operation between repairs. However, during my time in industry, I have witnessed centrifugal pumps that were problematic for a multitude of reasons. Often, pump problems are caused by either abnormal pump wear, pump assembly issues, or unexpected interactions between the pump, driver, piping, valves, and controls.

Basic troubleshooting matrixes are too limited in scope to identify complex or uncommon centrifugal pump situations. A simple matrix approach restricts the users to a limited number of common root causes. The real world is much more complex and can stump even the most seasoned pump professional with rarely seen root causes. Advanced pump professionals need to have a troubleshooting methodology that can dig deeper into field problems.

In general, a troubleshooter must first detect an unwanted symptom, such as a high temperature, low flow condition, high vibration level, etc., and then identify possible causes of the symptom. The troubleshooter must then try to determine the most likely cause related to the observed symptom and determine the most cost-effective means of correcting the systemic deficiency. An observed deficiency may be the result of pump degradation, a repair error, a design error, an installation error, a control problem, a processing error, or a pumping system issue. Often, troubleshooting is an iterative process where the machinery professional must interpret field data, postulate the possible cause, make a correction, and then see if the correction was effective or not. If the symptom persists, then the troubleshooter must try another correction aimed at eliminating the symptom. In complex or rare situations, the pump manufacturer may have to be consulted.
If you conduct centrifugal pump field assessments or are responsible for maintaining the integrity of centrifugal pumping systems, this book is for you. You will find specific troubleshooting advice for commonly encountered pump suction configurations, such as those with flooded suctions, lift suctions, and submersed suctions. By applying the troubleshooting methods presented in this book, pump professionals will begin to see their pump problems differently and improve their chances of uncovering the true cause or causes of the observed symptoms, in a timely manner.

Robert X. Perez