A Hazard and Operability Study, or HAZOP, is a systematic examination of a complex process to identify hazards and operability problems before they can occur. A longtime Omni customer recently invited one of our senior technicians, who was very familiar with their operation, process, and challenges, to participate in a HAZOP concerning their newly-installed tanker loading arm system. After reviewing the system and observing the loadout area with the plant’s process manager, our technician determined what instruments and controls would be needed to safeguard personnel and equipment while helping to streamline the loading process.
Omni’s first recommendation was to install a pan-tilt-zoom (PZT) CCTV camera at the loading platform as it was somewhat distant from the main building. This would allow control room operators to observe loading at all times. Next, our technician recommended installing three E-stops, one on each side of the tanker bay and one on top of the loading platform, to allow immediate shutdown of the loading process should an emergency occur.
The next concern was how to prevent overfilling of the tanker trucks. The loading area was equipped with a truck scale and a quality mass flowmeter to measure fullness, but our technician determined that an additional fail-safe measure was needed. After conferring with the loading arm system manufacturer, we recommended installing a level switch made specifically for the application at the tip of the loading arm to halt filling should an anomaly occur.
Lastly, we recommended installing simple green-yellow-red indicator lights that would alert the filling operator to the current status of the process. This safety measure, in addition to existing radio communications and a control tablet, would let the operator know if the filling process was running properly, experiencing problems and needed to be put on standby, or had become unstable and needed to be stopped.
The plant manager, process manager, and design engineer agreed with Omni’s HAZOP recommendations and are currently in the process of making the changes.