Wireless Automation for Safety

• Lots has been done for safety, but plant operations are still challenged with incidents
• Work in the plant is transforming by expanding and automating data collection and interpretation
• The recommendation is for the I&C team to deploy software and sensors, but these must have some important characteristics
• The result is greater occupational safety and autonomous operation

Just to be clear, wireless is not used for functional safety, that is not what we are talking about here.

Health and safety managers and their teams of experts work to keep the plant a safe place to work. We need to give them great tools to be successful. Industrial Internet of Things (IIoT), digital transformation (DX), and Industry 4.0 are heralded as key solutions and methodologies, and they are, and all of them are about automation. The 28th of April is the SafeDay - the World Day for Safety and health at Work by the UN International Labour Organization (ILO) so like in previous years I’d like to share some ideas on how to make safety and health management in plants easier by providing personnel with new automation tools. Let’s examine how the work of safety and health engineers is changing with wireless sensors. And it doesn’t have to be difficult. It can be done by safety and health engineers working with your I&C team. What are the recommended practices for the I&C team to build and support these solutions to provide real-time situational awareness? Here are my personal thoughts:

The most important fact that many have missed in the past is that the wireless sensor network (WSN) technology you choose makes a huge difference in the long-term viability of these occupational safety and health monitoring solutions. With the wrong WSN you cannot pull current information from sensors on demand when you need it, and you cannot easily integrate the sensor measurement data into analytics and other third-party platforms and apps without costly coding and scripting.

Plant Challenges

Safety and health challenges in a plant include incidents which leads to injury and damage. Slow emergency response which leads to longer recovery period. People in high-risk areas which may lead to exposure to hazardous material or other hazards associated with the location. Many of these stems from manual practices like manual data collection walking the plant and manual data interpretation. This includes manual valve checks, level inspection, gas sniffing, pipe thickness testing, and other manual data collection. This is time consuming and labor intensive so manually checking hundreds of positions daily or even weekly in large plants is a real challenge. Daily inspection is too infrequent to be responsive. But more frequent manual checks would be impractical. Moreover, distress calls are also manual. These are the reasons why plants want to change how safety and health is managed.

Work Transformation

The new ways of working, of managing safety and health include automatic data collection for situational awareness. This is the vision of how plants want to change how safety and health is managed. Now, just like you can’t drive your car looking at the accident forensics, you must look at the real-time indicators on the dashboard, you cannot run a plant looking at the incident reports either, you need to provide real-time risk profile information like the status of preventive and recovery barriers.

The New Automation Solutions

To achieve this vision, plants deploy Industrial Internet of Things (IIoT) and digital transformation solutions which is just another name for automation solutions. Most of these solutions are a combination of ready-made analytics software for the automatic data interpretation and underlying sensors for the automatic data collection. This is a second layer of automation, beyond the P&ID, what some refer to as hyper-automation. Engineering is where the vision statements of holistic transformation come down to implementation to address individual use-cases. Popular examples of situational awareness solutions include packages for emergency safety shower and eyewash stations, manual valves, flammable gas, toxic gas, tank (overfill), breather valves and blanketing, pipe (corrosion), and keeping people out of high-risk areas. The recommendation is to start with these use-cases, but there are more.

Emergency safety shower and eyewash stations

In many plants the emergency safety shower and eyewash stations are still not monitored. A lone worker that suffers a splash of chemicals washes it off but must at the same time manually make the distress call for help on their radio set. And must have the presence of mind to explain to the emergency response team where in the plant they are. This takes precious time which leads to more serious injuries which in turns slows the recovery.

Sensors

The recommendation is to add proximity switches on both eyewash and shower with a wireless transmitter to take the place of manual distress calls on the radio for timely notification of activation implicitly including the exact location. With this information, the rescue team can act faster minimizing chemical burns thereby reducing injuries and accelerating recovery. Optionally additional sensors can be added to detect freezing or loss of water pressure. This is additional information useful to schedule timely repairs. The exact configuration of sensors depends on the requirements. Safety and health engineers work together with the I&C engineers to determine which sensors are required on each piece of equipment.

This is alerting, data collection, and input that in the past required manual reporting and a human to go out with portable a tester or reading mechanical gauges. By automating the alarming it gets reported within seconds, and by automating data collection, it gets done once a day, once an hour, once a minute or every few seconds - not just once a year. This was not possible with a manual process. Sensors are permanently installed on equipment in every corner of the plant. With these sensors, personnel can “inspect” many more pieces of equipment than what was covered manually in the past.

The recommendation is to add wireless and non-intrusive sensors as they require no power cord, no signal wires, and no I/O cards. And there is no cutting, drilling, or welding required for installation of many of these sensors. That is, many of these sensors can be installed while production is running.

Manual valves

Manual valves are everywhere in the plant. Service include fill, sampling, drain, isolation, bypass, and more on vessels, lines, dykes, and more. Many of these are used in startup, shutdown, loading, and offloading etc. A manual valve left in the wrong position can be a serious threat causing overfill, spill, rendering a safety device inoperable, and mix of incompatible materials etc. in turn leading to incidents.

The recommendation is to add position sensors on manual valves to take the place of manual checks. With this information, operational errors can be reduced. The exact configuration of sensors such as simple open-shut or 0-100% opening depends on the requirements. Operators and safety engineers work together with the I&C engineers to determine which sensors are required on each manual valve.

The impact the sensors have is the same as described for safety showers above. The required sensor attributes are also the same as for safety showers.

Flammable gas

Flammable gas may leak from damaged flange gaskets, pump seals, compressor rod packings, valve stem packings, hoses, and many others.

The recommendation is to add combustible gas sensors to take the place of manual rounds with portable testers to automatically detect combustible gas leaks. With multiple sensors across the plant, leaks are detected sooner, and it is possible to closer identify the area where the leak is occurring. The exact arrangement of sensors depends on the size and layout of the plant. With this information, the combustible leaks can be stopped sooner thereby reducing risk. Safety engineers work together with the I&C engineers to determine which sensors are required across the plant.

The impact the sensors have is the same as described for safety showers above. The required sensor attributes are also the same as for safety showers.

Toxic gas

Toxic gas such as hydrogen sulfide (H2S) and carbon monoxide (CO) may leak from damaged flange gaskets, pump seals, compressor rod packings, valve stem packings, hoses, and many others. Another issue in confined spaces is oxygen depletion.

The recommendation is to add toxic gas sensors to take the place of manual rounds with portable testers to automatically detect toxic gas leaks. Different sensor types are required depending on the type of gas to be detected, as well as for detecting oxygen (depletion). With multiple sensors across the plant, leaks are detected sooner, and it is possible to closer identify the area where the leak is occurring. The exact arrangement of sensors depends on the size and layout of the plant. With this information, the toxic leaks can be stopped sooner thereby reducing risk. Safety engineers work together with the I&C engineers to determine which sensors are required across the plant.

The impact the sensors have is the same as described for safety showers above. The required sensor attributes are also the same as for safety showers.

Tank (overfill)

When tank level measurement fails, or if it is non-existent, the tank can overfill which leads to incidents.

The recommendation is to add a secondary level sensor to take the place of manual rounds with dip stick, reading sight glass, or gauge to automatically detect high level. The exact configuration of sensors such as point switch or 0-100% full depends on the requirements. Level sensor types may include vibrating fork switch, guided wave radar, differential pressure, or free space radar depending on the product and tank configuration. Operators and safety engineers work together with the I&C engineers to determine which sensors are required on each tank. With this information, tank overfill can be prevented thereby reducing risk.

The impact the sensors have is the same as described for safety showers above. The required sensor attributes are also the same as for safety showers.

Breather valve and blanketing

When storage tank pressure / vacuum relief vents (PVRV) a.k.a. breather valves fail the storage tank can explode or implode during filling, emptying, or when there is a temperature change.

The recommendation is to add proximity sensors on breather valves to take the place of manual checks. With this information, catastrophic filling and emptying incidents can be reduced. Tank blanketing failure can also be detected. This solution is often used together with emergency vent valve monitoring. Safety engineers work together with the I&C engineers to determine which sensors are required on each breather valve.

The impact the sensors have is the same as described for safety showers above. The required sensor attributes are also the same as for safety showers.

Pipe (corrosion and erosion)

Pipes can rupture due to wall thinning because of corrosion and erosion. The cause & effect, the symptom, which is a leading indicator of impending failure is well understood.

Software

Software, an analytics app, based on AI is used to automatically predict rupture due to wall thinning because of corrosion and erosion in pipes and vessels. The recommendation is to use a specialized corrosion/erosion app with special features for corrosion/erosion analytics.

This is analysis and prediction that in the past required a human with expert know-how. By automating the analysis, it gets done continuously, not just once a month. This was not possible with a manual process. With these automatic tools, personnel can manage many more pipe sections and vessels than what was analyzed manually in the past. Experts can focus on the pipe sections and vessels requiring attention, without wasting time on those that don’t.

The recommendation is to use readymade apps using mechanistic AI embedding the well-known cause & effect relations to predict using real-time sensor data. With this approach years of historical data, data cleansing, algorithm training, modelling, and testing is not required. The predictions are deterministic, not probabilistic. The safety and integrity engineers are responsible for the safety of the piping and vessels and therefore need this information in software on their laptop at their desk, so this information shall be displayed in apps for them, not in the DCS operator console in the control room, because that is not where they work. It’s the same app framework for the various kinds of equipment in the plant.

Sensors

The recommendation is to add Ultrasonic Thickness (UT) sensors to take the place of manual rounds to automatically collect the data required by the analytics for robust and timely prediction.

The impact the sensors have is the same as described for safety showers above. The required sensor attributes are also the same as for safety showers.

People in high-risk areas

The plant has greater risk than the office. The plant may have flammable and toxic materials, biological hazards, high pressures, extreme temperatures, high voltage, pinch points, slip, trip, and fall hazards, noise, weather, ionizing radiation, and UV radiation etc.

Automating all manner of manual data collection with permanently installed sensors has the additional benefit of keeping people out of harm’s way, thus making the plant a safer place to work. People may even be able to work from home (WFH) a few days a week. This is particularly advantageous during pandemics like COVID.

The recommendation is to add vibration, differential pressure, temperature, multi-temperature, acoustic noise, and flow sensors to take the place of manual rounds to automatically collect the data required to detect out-of-limit conditions.

The impact the sensors have is the same as described for safety showers above. The required sensor attributes are also the same as for safety showers.

Operational Excellence in Safety

As a result of improved situational awareness enabled by these new automation tools, the plant will see improvements in reduced incidents which brings fewer injuries, reduced damage, repair cost, and cleanup cost. Faster emergency response which brings faster recovery. Reduced number of people in high-risk areas which brings reduced exposure hazards.

But, if this additional automation is not deployed, the plant will remain stuck in its old ways, which might be good, but not great. And for a new plant that does not put in the additional automation sets itself up for a reactive safety and health culture and sub-par occupational safety and health.

Wireless Sensor Network Requirements

Sensors are critical to improving safety and health management because analytics software without sensors is like a brain without senses. In an existing plant, wireless sensors are the only practical way since laying cable to hundreds or thousands of additional sensors in a running plant is impractical. That is, the I&C team in the plant must deploy wireless sensor network infrastructure if it doesn’t already have it.

Analytics software without sensors is like a brain without senses.

Now, there are many wireless sensor network (WSN) technologies being touted for plants to choose from, but most are not suitable for plant use-cases because when they were created, they were optimized for other use-cases such as on your person and in your home, smart city, or agricultural use-cases etc. And in some cases the radio technology is proprietary. All those WSN technologies therefore lack features that are critical to large-scale operations in process plants with hundreds or thousands of sensors, solving dozens of use-cases, using sensors for dozens of different kinds of measurements. These critical attributes include automatic conversion of sensor measurement data to OPC-UA and Modbus, central sensor configuration, and common sensor diagnostics management.

Be conscious to not inadvertently direct all your attention solely to one type of sensor, solving only the use-case at hand, forgetting about capabilities of the WSN, because you might end up with the wrong WSN not suitable for many of the other sensor use-cases around the plant you will have to tackle in the future.

Multi-vendor Interoperability

Safety and health use-cases around the plant require sensors for discrete contact, position, gas concentration (H2S, CO, O2, and others), level (differential pressure or guided wave radar), level switch, and ultrasonic thickness (corrosion and erosion). Other use-cases for occupational health, safety, and the environment (HS&E), as well as reliability, maintenance, and integrity also require sensors for vibration, quad-temperature, differential pressure (including level and flow), pressure, acoustic noise (steam traps and relief valves), pulse (turbine flow), and wireless adapter (on non-wireless flow meters and level transmitters). Managing multiple WSN in a plant would be a lot of work. The recommendation is to use a single WSN to support all these sensor types. Therefore, when you select a WSN technology for your plant, make sure you can find local vendors for all these sensor types, not just the type of sensor you require for the project at hand. Keep in mind that wireless sensors need national approvals (e.g. radio spectrum), so although a vendor have a particular type of sensor on their website, you need to make sure it has the approvals for use in your country.

The recommendation is to deploy WSN infrastructure based on the WirelessHART (IEC62591) standard. This standard supports sensors from multiple vendors covering all these sensor types.

Automatic conversion to OPC-UA and Modbus

Many vendors offer a bundled kit of wireless sensor plus an app for a specific use-case. At a first glance this may look as if it solves the problem at hand, but in the larger scheme of a plant, such point solutions are not practical because the sensor data is trapped within the bundled app. To improve how work is done in the plant, sensor measurement data must also connect to third-party software apps like the historian, analytics, visualization, and maybe even the control system. Therefore the sensor measurement data must be made available using standard industrial protocols and software interfaces. For most WSN that would require custom coding/programming to a non-standard API or scripting to parse vendor-specific data formats. A system integrator has the programming/scripting skills to setup the system, but it is time consuming and costly, so it usually does not get done. But the worst part is that plant personnel will not be able to support it long-term. When OS and software is patched and upgraded, APIs will break. When devices are replaced, different data parsing is required. The system integrator needs to be called in to fix the code or script when a sensor is replaced. That is, most WSN technologies do not provide simple data integration even though the radio may be based on a standard, or the protocol may be a standard.

The recommendation is to deploy WSN infrastructure based on the WirelessHART (IEC62591) standard. This technology uses well-defined data formats which enables automatic conversion of sensor measurement data to OPC Classic (OPC-DA), OPC-UA, Modbus/RTU, Modbus/TCP, HART-IP, and other standard industrial protocols in the wireless gateway. That is, custom coding/programming or scripting is not required. Existing and future systems and software in the plant can easily tap into the sensor measurement data. IP-based protocols like OPC-UA, Modbus/TCP, and HART-IP can run all the way to software in the cloud if required. Sensors can be replaced without calling in a system integrator. The risk associated with software patching and upgrade is greatly reduced.

Central sensor configuration

Most WSN only support transmission (publication) of sensor measurement value with simple status. The sensor cannot receive configuration data over the WSN. That is, changing the sensor configuration (such as type of temperature sensor or engineering unit) requires you to travel to site to change the configuration locally at the sensor, which is inconvenient in any plant, but particularly troublesome for offshore installations and other remote sites.

The recommendation is to deploy WSN infrastructure based on the WirelessHART (IEC62591) standard. This technology supports both reading and writing of data from a remote location making it possible to centrally configure sensors from configuration software or an intelligent device management (IDM) system. Moreover, gateways support the HART-IP protocol which seamlessly carries the data between the gateway and software such that additional integration effort is not required to setup such capability. Sensors from multiple vendors can be configured from the same software. Sensors can therefore be configured without going to site.

Common sensor diagnostics management

Again, most vendors offer a bundled kit of wireless sensor plus an app, and the health of the sensor, its diagnostics, is only displayed in that app. Once again, at a first glance, this may look as if it solves the problem at hand, but in the larger scheme of a plant, such point solutions are not practical because with the wide selection of sensor types required in a plant, the I&C engineers that support the sensor system would have to open multiple apps, possibly on multiple computers, in different locations, to see the health of all sensors. This would not be practical.

The recommendation is to deploy WSN infrastructure based on the WirelessHART (IEC62591) standard. This technology uses well-defined data formats which enables a single common software to display the health of sensors, and status of their individual measurements, from multiple vendors. No need to wade through multiple apps. Moreover, gateways support the HART-IP protocol which seamlessly carries the data between the gateway and software such that additional integration effort is not required to setup such capability. The health of sensors from multiple vendors can be monitored from the same software.

Action Plan: Transformation by Wireless Automation

Again, to be clear, wireless is not used for functional safety, that is not what we are talking about here.

Transformation of safety and health management requires automation such as wireless sensors and specialized analytics apps. Therefore the recommendation is for companies to assign larger budget to their I&C departments to enable them to deploy the automation required to transform how work is done.

For existing plants:

• Deploy WirelessHART sensor network if you don’t already have it
• Change mechanical gauges to wireless sensors
• Deploy wireless sensors in manual testing positions
• Fit control valves with smart positioners and wireless adapters
• Deploy analytics software
• Deploy OT data management if you don’t already have it

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For engineering specs:

Wireless sensor network gateway:

• Shall use WirelessHART
• Shall have sensor measurement data conversion to OPC-UA and Modbus/TCP
• Shall support HART-IP pass-through

Wireless sensors:

• Shall use WirelessHART

Intelligent Device Management (IDM) software:

• Shall support HART-IP
• Shall support FDI

For new projects:

• Include WirelessHART sensor network
• Specify wireless sensors instead of mechanical gauges
• Specify wireless sensors in place of manual testing positions
• Specify smart positioners for control valves
• Specify control system with HART support in AI and AO cards
• Include analytics software
• Include OT data management

?

Lead the way. Schedule a meeting for 28th April, SafeDay, or today.

Share this essay with your safety and health managers now.

And remember, always ask vendor for product data sheet to make sure the software is proven, and pay close attention to software screen captures in it to see if it does what is promised without expensive customization. Well, that’s my personal opinion. If you are interested in digital transformation in the process industries click “Follow” by my photo to not miss future updates. Click “Like” if you found this useful to you and to make sure you keep receiving updates in your feed and “Repost” if you think it would be useful to others. Save the link in case you need to refer in the future.