A key non-traditional arena where wireless instrumentation is proving its worth is in the monitoring of safety infrastructure, including safety showers and pressure relief valves.
At Lion Oil's El Dorado, Ark., facility, for instance, remote safety showers are equipped with Rosemount 702 Wireless Discrete Transmitters and TopWorx GO Switches and Brackets to alert operators when a safety shower has been activated. This provides an immediate alert to emergency personnel and a digital record that the event occurred. "The discrete switches on the showers would easily have cost $10,000 each to wire," said Wilson Borosvskis, Lion Oil instrumentation and control engineer.
At a paper mill in Idaho, eyewash stations are wirelessly instrumented, in part because drivers unloading chemicals don't have a direct communication channel with operators. Although they use lots of radios at the plant, none of the contractors and only some of the employees have them. By installing a wireless network instead of a traditional wired network, they were able to save about 60 percent in installation costs, and know immediately when and where there is a safety issue.
In another non-traditional instrumentation application, the Rosemount 708 Wireless Acoustic Transmitter can be configured to detect the discharge of a pressure relief valve (PRV) and automatically alert operations. And while a PRV is technically a piece of safety equipment itself, acting to prevent a high pressure excursion from escalating to catastrophic failure, a PRV release often implies an environmental emission (and potential fine) as well as an accompanying root-cause condition that merits further investigation.
Automate Monitoring, Ensure Compliance
In its broadest sense, plant safety includes not just plant personnel but people and the environment outside the plant's perimeter as well. Also critically important is compliance with current safety and environmental regulations, along with the ability to prove being in compliance to regulatory authorities.
Demonstrating compliance often hinges on accurate record-keeping, a constant challenge in even the most organized plants. But Rosemount instrumentation is designed to help with these tasks, too. Date stamps and audit trails built into each product show when measurements have been taken and other compliance-related tasks performed. Further, this information is collected and stored in an online database for easy access if an audit is requested. Experienced Emerson personnel can even help evaluate whether older instrumentation is running safely and in compliance: they'll do a top-to-bottom installation audit, identify high risk areas, make sure instruments are installed correctly, and make any adjustments needed to ensure devices are performing to specification.
For an existing plant challenged to keep up with an ever-changing regulatory landscape, wireless instrumentation is proving itself an especially cost-effective solution. This includes safety measures as well as the monitoring and prevention of environmental impacts.
Tank farms are a common beneficiary, as wireless savings rapidly compound in these often sprawling environments. At FH Tank Storage in Kalmar, Sweden, Rosemount 3051S Wireless Differential Pressure Sensors automate level measurement in 14 of the petrochemical terminal's smaller solvent and chemical tanks, while 15 Rosemount 5402 non-contacting radar devices with Smart Wireless THUM Adapters are on the larger tanks, many with floating roofs. "Not only has the new system improved the monitoring of tank levels, it has provided a fully approved overspill protection solution," says Lars Ferm, site manager. "The Smart Wireless network was relatively simple to install and both the network and the transmitters have been extremely reliable," Ferm says. And at another refinery site in the U.S., wireless level switches are on trial to provide an added independent protection layer (IPL) to the tank farm's primary instrumentation.
Safety Only the Start
These are only a few examples of companies that started down the wireless path with a specific regulatory compliance need in mind. Indeed, for many a process industry facility around the world, improved safety or compliance with an environmental regulation helped clear the initial justification hurdle for implementing its first wireless instrument network.
But once that first network is in place, they're discovering that new measurement points are easy and relatively inexpensive to add. This is opening their eyes to incremental applications that can advance other plant performance metrics such as production throughput, energy efficiency and asset utilization rates. Confident that their operations are now safe and compliant, they're pushing facilities to operate closer to their full potential.