The instrument shop was not happy. Kenny, recently transferred from upstream operations in Alaska, had embarked on re-instrumentation of the refinery’s aging east side without engaging with them. Before they could object, he’d installed hundreds of unfamiliar (to them) “blue” pressure, DP and temperature transmitters as part of a larger project to convert old pneumatic systems to a then-modern DCS. Their grumpiness was not a shock—general distrust and animus toward salaried ranks wasn’t uncommon. Their cozy circle of workbenches and sometimes light schedule made fertile ground for union agitators, already fired up about the new plant manager’s efforts to transform their refinery into a profitable one.
Prior to the new manager’s arrival, the refinery was run as sort of a crude-disposal unit: run as much crude as possible, and spare no expense to return the plant to production if it was shut down. For the diverse instrumentation of the 1970s and ’80s process plant, this refinery employed six salaried supervisors to direct 19 hourly instrument and analyzer technicians. The more reflective members of the salaried supervisors—themselves promoted from the union ranks—believed they were kept around for strike coverage. Strikes were expected in those years and management planned to keep the crude flowing regardless.
The resentment stirred by Kenny’s disregard for the instrument shop was a factor in finding many features to dislike about his choice of transmitters. Chief among their gripes was the need to change the DP capsule when re-ranging from 100 in. WC to 200 in. The base capsule (the transducer that converts the differential pressure to a precise electronic signal) could only be spanned to 175 in.
Over a period of years, the blue transmitters would be exchanged, one by one, by a new, smart transmitter, whose microprocessor-based temperature and pressure characterization allowed it to be spanned anywhere from 0-25 in. to 0-400 in. Kenny had gone back to Alaska; his project was a success, as far as management was concerned.
Such projects were common in the ’80s and ’90s, and were easily justified. Millions of dollars were authorized for new microprocessor-based distributed control systems, electronic transmitters and positioners to replace pneumatic devices. These projects were sold in a time of shrinking, sometimes negative, refining margins and cash flow. How did they sail through so easily?
Promises of improved profitability from advanced controls, savings from greater precision and running closer to product specifications, income from greater throughput and reliability were proffered. Most of these justifications were plausible, if not proven. But the slam dunk was one that required little insight into refining, chemical engineering or controls. It was a principle even the most anti-technology luddite manager could grasp: increased centralization and consolidation of control rooms meant fewer people.
"Workforce reduction," “rightsizing,” “reengineering,” whatever buzzword the consultant-du-jour peddles to senior executives, cutting bodies has been rewarded by investors and analysts for the past three decades. Sure, big corporations have deadwood that can be purged or bureaucracies that can be culled. And we can’t deny that improved automation and control through microprocessor-based systems means we can make processes run reliably and profitably with fewer people. As attrition and retirements occurred, the vacancies weren’t filled. Products kept flowing.
Thirty years have passed and today, there’s one supervisor and five instrument technicians. The loop count has gone up with mandated hydrotreaters and desulphurization units. Meanwhile, as we weigh the risks inherent in process plants, we find instrumented systems and alarms are increasingly relied on for risk mitigation.
Lean staffing looks great to analysts, but it’s become unsatisfactory to accept run-to-failure for many instruments and control systems. The remarkable reliability of modern instruments shouldn’t create complacency. Let’s make sure we have enough people trained to test and document their efficacy.
