For Problem Solving, Look at the System as a Whole
An insightful interview with Abhijit Ray Chaudhuri. Currently based in Kolkata, India, he is the head of the Pumping Systems Group inside the VA Tech Wabag organization. He oversees the selection, procurement and operational issues related to pumps, valves and the associated electrical and mechanical equipment in the water and wastewater sector.
Many years ago, Abhijit Ray Chaudhuri had the opportunity to listen to a lecture by I. J. Karassik, a Russian-American engineer known for his pioneering work with pumps. He wrote over 1,100 technical articles and papers on pump use and maintenance, as well as several books, including Centrifugal Pump Selection, Operation and Maintenance, Engineers’ Guide to Centrifugal Pumps and Centrifugal Pump Clinic. He also co-wrote Pump Questions and Answers, and co-edited the Pump Handbook. The lecture inspired Abhijit to forge a similar career path. “Karassik was the grand old man of the pumping industry and I heard him in a seminar at Delhi while in my final year of mechanical engineering in college,” Abhijit said. “Inspired, I joined Worthington Corporation in India as a graduate engineer trainee. I learned the basics there during my tenure, especially about chemical process pumps as well as pumps for water services. Since valves are an integral part of any pumping system, I picked up working knowledge of them.” Most notably, Abhijit gained knowledge about bypass valves used in the discharge line of boiler feed pumps, which had very few manufacturers at the time. After three years, he joined a major Indian engineering company, Voltas, which was in the field of EPC contracting in the water and wastewater sector. During his career, he has gained experience by working with major Indian pump manufacturers like Kirloskar (Owner of SPP Brand Name). For the past 10 years, he has been with VA Tech Wabag Limited, associated with pump and valve selection, evaluation, procurement and operation supervision. In all, he has the experience of approximately 34 years.
Now, as the head of engineering (T&D) for water and wastewater EPC/PPP projects in VA Tech Wabag Limited, he is currently based in Kolkata, India. Wabag is one of the world’s leading companies in the water treatment field. Wabag’s key competences, which are based on more than 90 years of plant building experience, lie in the design, completion and operation of drinking water and wastewater plants for both the municipal and industrial sectors. Wabag offers sustained solutions for special customer needs through a comprehensive range of services and innovative technologies. It facilitates environmentally compatible wastewater disposal and secure access to clean drinking water for an increasing number of people. This allows the company to make an important contribution to environmental protection and enhanced quality of life.
With many roles, Abhijit is also heading the Pumping Systems Group inside the organization and oversees the selection, procurement and operational issues related to pumps and the associated electrical and mechanical equipment. “Valves and penstocks play a major part of the equipment being handled by me,” he explained. “I am also working with the proposal team for correct and optimum selection of equipment during bid submission. I guide them for the most energy efficient and cost effective solution to offer to clients during the bidding stage itself and further help to optimize on them during the execution stage. My responsibilities also include troubleshooting during installation and operation.”
Abhijit currently works on a wide range of projects including water supply, water and wastewater treatment, wastewater pumping, sea water desalination and reverse osmosis projects in India, the Middle East and South/Southeast Asia and Africa. He primarily works with municipal bodies in India, National water supply companies, drainage boards in Sri Lanka, DAWASA in Tanzania, DEWA in the United Arab Emirates and similar organizations in the Philippines, Vietnam, Indonesia, Malaysia, Egypt and other countries. Abhijit has developed subject matter expertise in the design and execution of pumping systems for the water and wastewater industries. This also includes working out the most energy efficient and cost effective solutions for his clients.
Battery of High Head Horizontal Split Casing Pumps.
“We must remember that pumps and valves are controlling a complex system,” he said. “Hence, instead of looking at them as individual equipment, we should try to analyze the working of the system as a whole and how the equipment is affected. For example, excessive load on a pipeline can be responsible for shaft breakage in pumps and disc failure in check valves. In any system comprising of long pipeline, similar failure may occur due to unbalanced surge and the resulting water hammer.”
Tripping or burning out of the drive motor is a common phenomenon when the pumps are made to work in off design conditions due to lower-than-designed system head, he explained. “Another issue is the partial closure of oil dash pots of large check valves and the failure of butterfly valves due to the presence of localized high pressure in the pipeline. These are system related issues, and I am not dwelling on manufacturing problems here as it is expected that equipment manufacturers do not compromise on quality. The failure of the pump shaft and bearings due to misalignment is an issue, but we use the best resources during installation and employ stage-wise checks to ensure this does not happen.” The system-related issues need serious attention and can be avoided with proper system design, he said, which, even today involves a lot of human element and experience. “It is not possible to standardize all systems, except those inside plants,” Abhijit said. “However, municipal systems involving cross country work need to be designed by taking into consideration the project’s specific needs. This can solve most operational problems.”
Maintenance & safety tips
All manufacturers have O&M manuals, which clearly specify the checks to be carried out periodically. “My best advice is to follow them,” he said. “Check the working of the valve actuators regularly. Check the bearings regularly every month for lubrication. If the pumps are lying idle over a long period, rotate the shaft manually every week so that jamming is avoided. Check the alignment once a quarter as the pipe stresses have a tendency to pull the pump.” Safety checks are mandatory at all installations worldwide, he said. “All International Standards talk of similar safety checks,” he said. “I feel the tightening check of holding bolts is important. Also, checks on expansion bellows, perform operational checks of the valve actuators, and relay setting checks on control panels should be carried out one extra time before commissioning.” “Every day or every project is a challenge in itself, and I prepare myself to brace them accordingly,” he said. “To be satisfied after a day’s work is my aim, and I utilize my learnings and experience to counter the challenges faced during a typical working day or during execution of a project.”
A River Intake Pumping Station with Vertical Turbine Pumps.
Advice for young end users
With 34 years of experience, Abhijit hopes young engineers can learn from his knowledge. “Spend your initial months on the field, whatever discipline you belong to,” he said. “The most effective learning comes from physical familiarity with the equipment. You will be designing or selecting for a system so you should get the feel of it. Touch them while they are in operation. Listen to the noise. Feel the vibration. These are the two best ways they communicate with you. As you learn their language, by merely listening to the noises in a pumping station, you will be able to understand if the equipment is working satisfactorily, or if they are in pain. The operational problems you come across will help you immensely in your work, be it design, proposal, selection, evaluation or procurement. Operate and maintain your assets with the care they deserve. They are beautiful pieces of engineering and must be handled with care and affection.”