Contributing Re.engineer: Kerry Mathews
Challenge: During a maintenance call out on a steam drum, a set of three level transmitters were deviating with one deviating over 3 inh2o (shown in the picture below). Has the calibrated span widened 3 in or is the measurement off 3 in?
Solution: This was the ultimate process of troubleshooting the transmitter; as you can see, this is a manifold setup with tubing at the transmitter and also tubing at the high and low side of the steam drum. Initially, I block and bled the transmitter at the manifold and this caused the measurement to go to zero (in this case full scale) because the URV value is 0 (20mA). This validated that the high side reading was good. I then proceeded to pressure up the low side of the transmitter to 33 inh20. The transmitter responded by going to nearly -33.00 exactly. This proved that the low side of the transmitter was good, eliminating the transmitter as the issue. I then started looking for leaks and found that the tubing was leaking on the low side at the stream drum after the manual block valve. There was the culprit causing the drift and the deviation of a critical level transmitter. The "wet leg" water filled impulse line could have frozen during a recent freezing condition which could have compromised the fittings or tubing.
Results: Avoided a process upset or steam drum failure due to inadequate level protection. Long term solution is to install a different level technology such as radar or ensure that adequate heat tracing is provided for installations with water filled impulse lines.
Contributing Re.engineer: Kevin Lane
Challenge: Raw material consumption is one of the largest cost for any business and probably only second to labor. When you reduce the consumption of materials, there is significant cost savings which can add up to profits at the end of the day.
Solution: The most cost effective way a business or plant can improve their consumption is with accurate metering that is repeatable. Calibration is fundamental to the operation of an measurement system and without it, organizations can expect to have some level of uncertainty as it relates to their most critical operating indicators, commercial or inter-company transactions (goods sold or purchased). In a well- functioning measurement system, agreements are in place to ensure orderly transactions.
Results: One project that I completed saved right at $900,000 per year and we only spent $50,000 on the equipment. Another custody transfer project I completed saved $1 million per year and the equipment was only $30,000. At a total of $1.9 million, both of these projects yielded an immediate Return on Investment that can be realized year after year.
Impact: $1.9 million
Contributing Re.engineer: Lucas Laughlin
Challenge: A critical production unit was having some electrical reliability challenges with their variable frequency drive (VFD) technologies and they sought out the support from a power electronics subject matter expert to assist. The production unit had a VFD with full voltage bypass and if the VFD was to go into a fault then it would switch to running at 100% loaded. This kept some of the assets running but had the potential to cause other reliability risk that could possible led to a lost production of $3 million.
Solution: All of the VFD controls for switching back and forth were hardwired in the bypass cabinet, so the subject matter expert designed his own VFD to VFD bypass in a controlled environment. He also worked with a process automation resource to replicate the logic from the bypass cabinet to the control system. You could not tell the difference of switching from one VFD to another when a “test” asset was switched in this environment. Before applying this improvement, there was a 2 second delay, which would have caused the aforementioned production losses.
Results: The production team will be implanting this strategy during the next window of opportunity and at another production facility within North America. There are some hard dollar savings as well because the purchase of a “bypass cabinet” alone would be $100,000 but having a second drive and other supporting equipment is 50% of that, total value creation > $3 million.
Impact: >$3 million
Contributing Re.engineer: Brant Smith
Challenge: SIS testing required multiple resources and valuable time during an outage. This effort took multiple crews around the clock and the logic testing was typically critical path delaying start-up [What is SIS? It is a distinct, reliable system used to safeguard a process to prevent a catastrophic release of toxic, flammable, or explosive chemicals].
Solution: A couple of solutions were utilized in an effort to reduce the impact of SIS testing. A pm was setup to proof test redundantly configured devices on-line. In addition to on-line testing, an automated testing software was utilized in place of a paper procedure to validate the logic.
Results: Decreased man-power cost during outage and removed testing from critical path. Automated testing software improved repeatability, efficiency and quality of the testing.
Impact: $1 million in revenue and $0.5 million operational savings
instrument & electrical case studies
This section of case studies feature technologies that align to the instrumentation and electrical disciplines.