Process Engineering Troubleshooting

Troubleshooting is an essential skill for process engineers across many different industries, and although there are substantial differences between industries in which process engineers work, the foundations and principles for effective troubleshooting are the same. This post will outline the foundations and principles that can be used to effectively troubleshoot all types of problems, and assist both new and experienced engineers in growing more competent in troubleshooting.

Troubleshooting Foundations
Much as a building needs a solid foundation in order to stand, effective troubleshooting also requires a solid foundation. One important difference, however, exists in the analogy of a building foundation to a foundation for effective troubleshooting – in a building the foundation needs to be complete before the building can be constructed, but in troubleshooting the foundation can be continually improved and developed in order to make troubleshooting more successful.

Many of these foundations are not only key to effective troubleshooting, but are also important to the overall success of the process engineer that is working to support plant operation. Here are some important foundational activities that should be continually developed:

• Understand how basic process equipment (such as pumps, heat exchangers, distillation towers, separators, etc.) works, and typical operating problems and issues.
• Learn from equipment and process specialists and use them to assist in troubleshooting.
• Understand key engineering principles and rules of thumb, and be prepared to use them while in the field troubleshooting.
• Read troubleshooting case studies and incident reports. You can very effectively learn from the past and the mistakes of others.
• Know the process unit that you are responsible for from front to back. Understand how the unit fits into the overall plant (both from a process flow standpoint and an economic standpoint).
  • Know the key instrumentation and control schemes for the unit.
  • Know where key piping and equipment is located, and how they relate to each other in terms of location.
  • Know the key physical properties for each unit feed and product, and what these materials normally look like.
  • Know the key unit parameters when operation is “normal”, so that it is easier to identify when the unit is “unhealthy”.
• Talk (a lot) to the people that run the unit and understand what kinds of things they see while operating the unit.
  • What are the constraints on unit operation?
  • What is the most important thing to them in terms of unit operation?
  • What kinds of things give them trouble with regards to unit operation?
• Have the proper troubleshooting tools available for use, and be familiar with how to safely use them.
  • Pressure gauges (of the right scale and materials of construction). Have a manometer for use in vacuum systems.
  • Temperature instruments – portable thermocouple/surface contact probe and non-contact (infrared).

Having a solid foundation will not only assist the process engineer in troubleshooting, but will also help them to be more effective in day to day activities and in making the plant in which they work safer and more profitable.

Troubleshooting Guidelines
In order to effectively troubleshoot problems, the following guidelines can be used to systematically attack the problem so that the problem can be understood and the best solution to that problem identified and implemented.

Before tackling a troubleshooting problem, however, it is important to always keep safety in mind – be familiar with all of your plant’s safety requirements and make sure that you are not taking any shortcuts with regards to PPE or safe work practices. Always listen to the safety concerns of others and stop work activities if an unsafe situation develops.

• Understand the Problem
  • Do not jump to conclusions about the cause of the problem. Collect the evidence and let that evidence point to the diagnosis.
  • Do not rush to use more advanced technology until you have collected more basic information. Although tools like gamma scans or tracer tests can be valuable, it is better to understand the basics before investing in more advanced techniques.
• Identify the symptoms of the problem – don’t skip to the diagnosis.
  • Identifying all of the symptoms will point to the problem diagnosis. It is important to remember that symptoms can have multiple reasons for occurring.
  • Tower flooding is a diagnosis, not a symptom. The symptoms of tower flooding can include high pressure drop, liquid carryover, and poor fractionation – but these can also be symptoms of other problems.
• Collect data around the problem symptoms
  • Background information (PFDs, P&IDs, Equipment Drawings and Datasheets, prior test run data, historical information)
  • Collect current system data (flows, temperatures, pressures, stream quality information). Don’t just look at data from your plant historian – verify in the field if possible.
  • Observe the symptoms for yourself if possible – both from the control room and in the field.
  • Use your senses (sight, sound, touch, smell) while observing the symptoms.
  • Talk to the people involved – Console/Board Operators, Field Operators, Supervisors, other engineers. Listen to what they have to say – although they may offer an incorrect diagnosis it is important to listen to what they have to say and understand their observations.
  • Understand from personal observations and from the people involved the timing of the problem symptoms. When are the symptoms seen? Are they continuous or intermittent? Can the symptoms be reproduced by adjusting operation?
• Organize and analyze the data
  • Draw pictures of the system and use graphs to assist in the analysis of the data. A picture is worth 1,000 words!
  • Develop potential hypotheses for potential causes based on the data that you have collected.
  • Test the hypotheses or collect additional information as needed to support or discount each of the leading hypotheses. Use advanced technology to assist in collecting additional information (such as gamma scans, tracer tests, etc.).
  • As hypotheses are supported or rejected, you can “zero in” on the cause of the problem and on potential solutions.
  • Try not to get attached or biased to any one hypothesis too quickly (your own, your bosses, outside experts, etc.). Becoming too attached can result in wrong conclusions, and become a waste of time and money.

Using these foundations and guidelines for troubleshooting can help process engineers to successfully diagnose equipment and unit problems and to propose solutions. Successful troubleshooting will lead to improved plant safety, reliability, and increased profitability.

Read on to Part 2 of this series to see how these principles can be applied in practice.