If you could replace one device in your operation and reduce the time required to complete a process from two days with the help of many technicians, to less than one minute, without a single operator, chances are, you’d jump at it. That’s exactly what happened with one of the largest midstream logistics companies in the United States, as they were able to significantly reduce its operating costs and enhance profits by upgrading its level detection technology.
The company operates over 100 compressor stations and each compressor station has two scrubber bottles per compressor. The scrubber bottles knock out any residual fluid from the gas stream before entering the compressor. A high-level alarm prevents damage to the compressor since it works as a watchdog for the dump valve level switch. A separate level switch operates the dump valve to remove fluid build-up in the scrubber bottles.
Previously, the bottles had a float switch installed for a high-level alarm. Company policy required that the unit be shut in, to check whether the high-level float switch was functional. However, shutting in the vessel resulted in lost time, lost production, and maintenance scheduling. Bucket testing the float switches caused multiple safety concerns.
Because the company identified the need to make the scrubber bottles area more efficient and cost-effective, it selected Emerson’s Rosemount 2140 SIS Level Detector because of its unique remote proof-testing capability. Remote proof-testing is available using a HART® command or push button. The test can be performed “in-process” and takes less than one minute to complete while the process is continually monitored and any challenge to the device state is reported immediately upon test completion. In addition, the detector integrates into existing wired HART loops of automated systems without extra wiring costs. It provides increased safety under IEC 61508 certified (SIL 2) as required by IEC 61511. The device is virtually unaffected by turbulence, foam, vibration, solids content, coating products, and liquid properties and an adjustable detection output delay prevents false detection in turbulent or splashing applications.
The Rosemount 2140 was the perfect technology upgrade. It’s remote proof testing enabled the company to confirm its high-level alarm operation without having to shut in the scrubber bottle or compressor. This was significant because it took up to two hours to test the float switch each time the scrubber bottle was shut in. Because the float switches were tested biannually per company requirements, which involved removing the old switch and placing it in a bucket to verify proper operation, it was time intensive. There were also safety concerns with this process.
More than 200 Rosemount 2140 level detectors were installed throughout the fields with one, two, or three per compressor. The Rosemount 2140 remote-proof testing eliminates the need to remove the float, minimizes safety concerns, and frees up approximately 1,000 hours of maintenance time annually.
The company’s results exceeded its goals with the following benefits:
More information on the Rosemount 2140 level detector can be found here.