Near-misses occur at most plants. I’ve encountered an overpressure incident with a system operating about 100 psi above its code stamp; luckily, a heat exchanger gasket blew, relieving the pressure before anything more severe happened. Then, there was the BLEVE [boiling liquid expanding vapor explosion] that I averted during a startup: toluene filled the air around a vacuum tower I was inspecting; I had the presence of mind to glide down two flights of stairs before radioing in the situation.
Such experiences have altered how I handle assignments. I now approach every assignment meticulously. If I don’t understand something, then I won’t do it or let others do it until I figure it out. Once I have sorted out my thinking, I will run my conclusions by others and explain my thought process to them.
As a rule, I keep a close eye on those around me, especially young staff. Too often, they exhibit over-confidence. For instance, during a walk-down for a new instrument installation in a Class 1, Div. 1 area where personal chemical sensors regularly pop off unexpectedly, a novice pipefitter seemed a little too cocksure when we went over the hazards. I asked him to look at me. I told him that I hope he never has to remember the face of someone who died in an accident. He stopped smiling and said he got it. I hope he did.
Likewise, I counsel people investigating an incident or near-miss not to be too regimented or in too much of a rush to complete the probe — and never to forget the reason for such investigations. Unfortunately, usually production and maintenance staff must deal with daily operational issues while process and safety engineers must struggle with a growing backlog of projects.
This brings me to my next point: over-dependence on instrumentation. I’m not talking about safety instrumented systems but about regular sensors and controls.
Two personal experiences come to mind. In the first, a company installed a half dozen thermocouples to watch for a fire in a spray dryer instead of fixing the maintenance items and inherent bad design that caused the fires. When a fire then occurred, the superintendent wanted me to blame an operator who was out of favor; I refused. In the second, a plant set up a vaporizer over-temperature control to start a vaporizer rather than using the proper startup sequence, resulting in contaminated product going to reactors; the plug flow reactors ran for a month or so instead of the six months desired.
In the first case, the plant invested in instruments to mitigate accidents that were sure to occur — because fixing the design flaws would impact production!
In the second case, the only engineer who knew the programming had made a mistake. I identified the problem but didn’t have access to the control system to correct the error. Getting access meant dealing with plant politics, which is an anathema to me.
This brings up a larger issue: operating companies are straining to find personnel who can grasp hardware and software. Most engineers seem more comfortable working on software than process equipment. Moreover, they usually view data on computers in their office or home rather trying to uncover problems by visiting the control room or equipment in the field.
The way operators work also has changed dramatically. They used to spend most of their time walking down the equipment they oversaw. The control room was where they ate lunch. Today, many operators stay glued to comfortable chairs in air-conditioned control rooms staring at faceplates on screens all day long.
These changes have left many engineers and operators with a gap in their training. The mechanics and contractors called in when labor is in demand often know the process equipment far better. Sadly, the engineers who write the process descriptions suffer the most from this — and they know it.
So, heed some sage advice. If you’re an engineer who hasn’t been through a turnaround yet, take full advantage of it. (See: “Make the Most of Your First Turnaround.”) If you’re a turnaround veteran, still treat every shutdown as an important learning experience. Take lots of pictures of equipment when it’s torn down. Keep running histories of equipment and processes so you can pass along critical information to the next generation.
DIRK WILLARD is a Chemical Processing contributing editor. He recently won recognition for his Field Notes column from the ASBPE. Chemical Processing is proud to have him on board. You can e-mail him at email@example.com