By Keith M. Cowan, EI&C Team Lead, Brindley Engineering
Reliable and precise level measurement instrumentation and systems are imperative for process control and efficiency. Inaccurate, unreliable, or failing/end of life level instrumentation can result in unit upsets or trips, equipment damage, and potential safety or environmental problems. Welcome to Part 4 of Brindley Engineering’s 10-part series on Infrastructure Reliability. In Part 3 we explored electrical reliability. In Part 2 you read about process utilities, and in Part 1 we wrote about about the risk of neglective critical infrastructure and protecting what matters. In Part 4 we will talk about level instrumentation.
Variation in level measurement systems
The reliability of level measurement systems and level instrumentation varies from plant to plant and from industry to industry. From power plant boiler drums, to manufacturing systems storage tanks, and chemical plant tank farm storage vessels, our Clients rely on level measurement throughout their facilities for unit stability, inventory control, and custody transfer.
How to improve instrument reliability
A local refinery requested Brindley Engineering’s (BE) services to replace several existing level switches on their existing process drums and associated boots. The existing switches had reached the end of their service life, were providing false trip indications, and were impacting the overall process and unit operation and reliability. The original project scope was to improve the instrument reliability by replacing the existing float type level switches with modern tuning fork level switches and upgraded level chambers.
Re-evaluation of improvement plan
After further discussions with the Client and project team, the team decided to forgo the level switch replacement scope and instead proceed with single 4” chamber dual technology magnetic level indicators and transmitters with guided wave radar level transmitters. The single 4” chamber technology approach eliminates the need for multiple level switches, provides continuous level monitoring and alarming, and reduces the quantity of I/O required within the control system. This approach also eliminates the need for dozens of isolation, vent, and drain valves; improving the overall ease of maintenance and reliability of the entire level monitoring system.
Greater operational reliability, performance, and stability
The age-old saying is that if job is worth doing, then it’s worth doing well. The same principle applies to implementation of level measurement systems. If the process requires the measurement of level, then it’s worthwhile to select the appropriate level system, device, technology, and accuracy to ensure the reliability and precision of the measurements. This effort, in turn, provides our Clients with greater operational reliability, improved performance and safety, and greater unit and process stability.
More From This Series:
- Part 1: Infrastructure Reliability – Protecting What Matters
- Part 2: Utilities – Water quality and the effects of impurities on on-stream operability
- Part 3: Electrical – Condition evaluation of critical motors, transformers, and UPS systems
- Part 5: Piping – Loss of primary containment caused by poor pipe routing
- Part 6: Tanks – Settling, buckling, and fitness for service assessments
- Part 7: Structures – Structural degradation and the risk of systemic collapse
- Stay Tuned for – Part 8: Fireproofing – Fireproofing degradation, fire safety and corrosion of underlying steel
- Stay Tuned for – Part 9: Cooling Towers – Collapsed cells and effects on cooling water availability
- Stay Tuned for – Part 10: Project Controls – Understanding the big picture in real-time