Crude tank
Level measurement
The crude tank contains unprocessed and unrefined crude oil. Level measurements are necessary to control the amount of oil in the tank and to prevent overflow. To measure the level, non-contact radar level sensors are used. Level sensors which come in contact with the crude oil can fail because crude oil can be very viscous, especially during cold winters. Furthermore, the contacting element often requires maintenance.
The 9116B IS universal converter powers the two-wire style radar transmitter and isolates the signal, while the output is connected to the control system. The relay in the 9116B is configured as a window function alarm and provides an additional level of safety by switching if the tank level is unusually high or low.
Application:
> Need more information? Please contact us.
What are the challenges of crude oil level measurement in storage tanks?
Crude oil storage tanks present several measurement challenges: the interface between oil and water must be accurately detected to prevent water carryover to downstream units, heavy crude can coat and foul level sensing elements, and the tank farm environment is classified as a hazardous area. Signal conditioners like the PR 9106B provide intrinsically safe isolation for level transmitter signals while maintaining HART transparency, allowing operators to access diagnostic data from radar or guided wave radar level instruments without entering the hazardous tank farm area.
How does PR Electronics support crude oil interface level measurement?
Interface level measurement — detecting the boundary between crude oil and water in a storage tank — requires high-accuracy signal conditioning to preserve the resolution of the level transmitter. The PR 9106B HART Transparent Repeater passes the 4-20 mA signal with accuracy better than 0.1% of span and less than 16 microamp absolute error, ensuring the DCS receives a faithful representation of the interface position. The HART transparency allows remote configuration of guided wave radar transmitters commonly used for interface detection.
What safety and regulatory requirements apply to crude tank level instrumentation?
Crude oil storage tanks are subject to API 2350 (Overfill Protection for Storage Tanks) and often require SIL 1 or SIL 2 rated high-level shutdown instrumentation to prevent overfill incidents. The signal conditioning devices in these safety loops must carry appropriate SIL certification. PR Electronics 9000-series barriers are SIL 2/3 fully assessed per IEC 61508, making them suitable for both process control level measurement and independent high-level safety shutdown loops in crude tank farms.
