Although digitisation is an undeniable trend, regular inspection rounds with a defined maintenance plan will continue to be an integral part of plant monitoring and maintenance. Clear and easily legible/scannable markings are essential for these inspections. The identification systems in many old plants are in dire need of modernisation. By modernising, companies can pave the way for digitally supported maintenance rounds.
“I’d never go on vacation without my tablet. Or at least my smartphone.” These days, most of us can hardly imagine locating an address in a foreign city or even in our home town without a smart device. Technology that has long been the norm in our personal lives would also be desirable for many workers who maintain and operate systems in chemical plants. In such a scenario, a handheld device designed for industrial environments with explosion-risk zones would guide the worker through the large, compactly built facility to the exact device or machine that the employee needs to inspect.
Proper marking as the basis for proper maintenance
Actually, such solutions do exist. But in reality, these digital solutions still have a long way to go when it comes to supporting maintenance and inspection rounds. In fact, even the “road signs” are often missing, to use the analogy of the address search again. Or, the signs are totally illegible. Old plastic signs in brownfield plants may be weathered or even broken, metal signs are often filthy or corroded, and the numbers on them are barely decipherable. This might not be a problem if you know your plant like the back of your hand. Veteran employees can easily locate an “address” in the plant. But new employees or external maintenance contractors will have difficulty. This wastes time and, in the worst case scenario, can lead to mistakes. Operational safety suffers when a unit or pipeline cannot be clearly and quickly identified. There is a better route to efficient maintenance: clearly legible, standardised markings.
The most obvious solution is durable, easily decipherable signs, such as laser-engraved stainless steel markings. Plant operators can improve productivity and system availability by installing these markings on all components and equipment consistently throughout the plant. This alone ensures more consistent, error-free maintenance and repairs. For even greater efficiency, RFID tags can be used. These tags stay readable for a long time, even if a layer of dust forms on them.
Marking equipment immediately
Companies that are considering updating markings as part of modernisation measures in their plant should remember that “as-built” is rarely identical to “as planned”. Very often, the modernised system deviates from the plans by as much as 30%. Weeks after the renovation, the system has to be re-documented and re-marked, which involves a lot of work. However, some companies eliminate this problem before it can even arise and label each new piece of equipment immediately after installation. Some use RFID tags, others use stainless steel tags. Locally-installed marking systems facilitate this task. Instead of having to print an ID label several 100 metres away in the control room, installers can create robust markings directly in the construction trailer, with no delay and less likelihood of errors.
Standardised markings
Like many companies, K+S, based in Wunstorf near Hanover, Germany, also wanted consistent, standardised markings. The company’s in-house power plant had been expanded and modernised over decades. The plant identification system and documentation were not from a single source and were therefore not clear. Berghausen opted for a standardised, systematic marking system based on the Power Plant Identification System, or KKS. Once preparations were completed and as-built plans were digitised, Phoenix Contact created 4800 plant identification tags with the standardised labelling as well as QR codes to help employees locate the documentation for each piece of equipment. Another company focusing on high print quality is RWE AG, which uses bar codes in addition to the KKS key and a short description on its marking labels in the processing engineering environment. These can be used for damage reports during the maintenance process.
RFID transponders as the foundation for digital support
Companies like K+S or RWE that want to optimise the markings in their plants should consider the benefits of an RFID system as a forward-thinking solution. Phoenix Contact has already installed RFID tags at several companies as part of a full-service package. During that process, the company saw the bad state that many well-known companies are in. For many companies, there’s simply no way around it: They have to spend money to improve the situation. Easily readable RFID HF or UHF transponders, integrated into the marking or installation material, are an investment that will not only increase safety, but also pave the way to more advanced maintenance methods. One such method is the use of maintenance software on tablets. Better than any paper tracking sheet, this software guides the maintenance engineer to all components scheduled for inspection. It also makes documenting the inspection round easier. The employee can immediately confirm performed maintenance procedures online.
Actually, all companies with organised workflows have already established good processes for inspecting all equipment that is important for safety and availability. However, their practices vary greatly. If inspections are documented on paper, some items might be quickly checked off. For example, a safety shower that was supposed to be checked might not really get turned on. Mistakes can also be made when this information is entered in the maintenance system. In any case, this extra step costs time. A maintenance application on the tablet significantly simplifies tasks and improves results for the maintenance staff, thereby increasing plant availability.
The right wireless technology, plus security expertise
Fig. 1: Comprehensive WiFi coverage supports paperless maintenance sequences. Maintenance software on an industrial-grade handheld guides the employee and also enables fast, error-free documentation on site.
This scenario requires a wireless network that connects the tablets to the master MES at all times. As with markings and RFID, Phoenix Contact provides the essential hardware and services, unless a company already has these prerequisites in place. A WiFi network is suitable if industrial office equipment will be used to support maintenance processes. Numerous chemical companies, including large refineries, have already installed WiFi hotspots extensively. However, Phoenix Contact also provides wireless infrastructures for smaller companies whose automation departments are also responsible for wireless communication in the production environment. This service includes everything from design to installation to the IT security strategy. The right wireless technology is chosen based on the needs of users and can be anything from WiFi, GSM, 3G, 4G and Bluetooth to WirelessHART or the proprietary Trusted Wireless solution (Fig. 1).
Hybrid solutions using copper and SHDSL
A combination of wired and wireless solutions is also feasible. One example is a large company that wanted to connect its fire alarm systems over long distances. Instead of the giant wireless network originally planned, we recommended using existing cables wherever possible, many of which were still unused in the old facility. The result was a hybrid solution using SHDSL technology. SHDSL operates at bit rates of up to 30 Mbps, sufficient for monitoring applications, and can be combined with fieldbus and Ethernet networks. In the case of fire alarm systems, this means that more than 60% of the signals are transmitted via the existing copper cables, and the rest wirelessly (Fig. 2).
Fig. 2: The SHDSL modulation method enables existing cables to be used to transmit Ethernet or fieldbus signals. This allows for hybrid solutions in which the wireless network is used only for some signals.
Cluster management is simpler than office WiFi
Another option, which is particularly effective for smaller networks up to around 20 access points, makes WiFi suitable for industrial use. Office solutions of this size are mostly server-based, with complex security and user management. One alternative is cluster management, which greatly simplifies setup processes. With this method, only one access must be configured. This setting is then transferred to the other access points in the network. The necessary security-related parameter requirements are also met (Fig. 3).
Fig. 3: Process control teams can quickly and easily set up a WiFi network in the production environment using cluster management technology. All access points can be configured collectively via a web interface.
This option does not require much time and effort. As a result, even the most conservative users are currently testing wireless technologies in pilot experiments, at least in a small section of the production facility. The potential benefits are obvious. When company decision-makers see these advantages, they often quickly get on board. The MES and maintenance systems are already present in brownfield plants anyway. Connecting the team in the field to the online network is the last step in the process.
Outlook: From RFID to mixed reality
The last step for now, that is. Early adopters are already beginning to explore the benefits of augmented reality (AR) applications. The tablet, which has identified a piece of equipment via NFC or an AR marker, then displays further information on the camera screen, such as a data sheet, the maintenance manual or a video of all the procedures involved. Measured values such as tank levels or the temperature of sensors without local displays can also be displayed. Phoenix Contact is also gathering experience by using AR to visualise temperatures within plastic injection molding machines at its own facilities. The status of pumps or motors can also be displayed on an explosion-proof tablet or smartphone or, in the future, directly on the operator’s smart glasses. The operator can then use gestures to open a maintenance sheet or an exploded diagram and view it in 3D. Virtual and augmented or mixed reality have lost their gamer associations. Today, these scenarios are no longer just a fantasy. They are an everyday reality in our industrial engineering department and in-house tool shop. AR applications can effectively support operation and maintenance teams thanks to modern marking methods and a reliable industrial-grade wireless network (Fig. 4).
Fig. 4: Companies that have fulfilled the prerequisites for digitised maintenance by implementing clear markings and a reliable wireless network can go on to test the first mixed-reality applications for maintenance processes.
Contact Sheree Britz, Phoenix Contact, Tel 011 801-8200, sbritz@phoenixcontact.co.za
