Intelligent instrumentation: Be smart, be safe
17 September 2012
Intelligent instrumentation can make a major contribution to health and safety. Les Slocombe, Field Products specialist for ABB’s UK Measurement Products business, explains how.
ABB System 800xA at Imperial College, an integration platform that brings together plant services, applications and devices
Workplace injuries and ill health cost Britain £14 billion in 2009/10, according to the Health and Safety Executive. Some £6.3 billion of the total represents financial costs, while the remaining £7.6 billion represents the monetary value given to individuals' “pain, grief and suffering”. On large-scale heavy industrial sites, intelligent instruments and control systems could play a significant part in driving those figures down, preventing personal tragedies and giving businesses a much-needed boost in the process.
While heavy industries such as oil, gas and chemicals present special risks in terms of the potential for exposure to hazardous substances, these “added risks” are tightly regulated and take a high priority in the health and safety and accident prevention strategies of most companies. Perhaps for that reason, they actually account for very few of the health and safety breaches in these higher-risk businesses.
For example, in offshore oil and gas, “struck by moving objects” produced the most injuries in a single category, followed by “injuries from handling, lifting or carrying”, “slips, trips and falls” and “falls from height”. These four categories are the same sort of problems that afflict industries right across the manufacturing sector and beyond, and they accounted for 83% of all injuries offshore in 2010/11.
In other words, the vast majority of health and safety issues in industry arise from people walking around the plant and moving stuff about. Get people off the plant floor and you can eliminate much of the risk at a stroke. And that’s where an ability to automate and remotely monitor and control what’s happening on the plant floor comes in. All it takes is the application of a little intelligence in the control instrumentation.
In process industries – as opposed to production lines – much of the plant typically runs without the need for human intervention during normal operations. Maintenance is therefore the most common reason for people to be out and about on site, so optimising maintenance regimes is a great place to start. That includes maintaining the actual control systems and using them to help optimise maintenance across the rest of the plant assets.
The instrumentation that generally populates oil, gas and chemical facilities includes on- and at-line analysers and lab-based analytical instruments, flow, level, temperature and pressure instruments and valve automation products. And while some of these instruments are almost “fit-and-forget”, it takes considerable care to keep others operating at peak performance.
According to some reports, as many as 35% of maintenance trips into the field are for routine checks, 28% are for non-existent problems, 20% are for calibration shifts, 6% are for “zero off” issues and 6% for plugged lines. Just 4% are actually for failed instruments. So it’s no surprise to find that of those companies already making use of on-board intelligence, more than three quarters (77%) are looking to improve their maintenance, according to ABB’s new ‘How do you measure up?’ benchmarking survey.
Take calibration, for instance. Self-diagnosis has increased the calibration interval required for many instruments from six months to as much as five years. In other examples, diagnostic tools have become so sophisticated that they can even pinpoint when a particular area within a valve assembly or positioner is becoming worn.
Better still, health and safety is not the only thing to benefit from the arrival of instruments with built-in intelligence. A reduction in downtime thanks to on-board instrument diagnostics and predictive maintenance can help to drive down costs substantially. Field-based intelligence can typically improve overall efficiency by at least 2% during normal operations, with much greater savings possible during the plant start-up phase. Exactly how much value intelligence and improved efficiency can deliver depends on the specific application and the value of the products being processed.
Yet even with so much to gain, the intelligence available in today’s field instrumentation is chronically underused.
More than half of plant operators report that less than 20% of their control instrumentation is currently equipped with intelligence, such as Hart, Fieldbus or Profibus communications. Furthermore, even where there is the potential for intelligent control, almost half (43%) of plant operators report that they don’t use it.
So why are so many plant operators reluctant to take the plunge and get smart with their instrumentation? Many do not have the software tools in place to process the information that comes in, while others are anxious that it will be too difficult and complicated for them to manage. But today’s control software is designed to be straightforward and user friendly, with systems and interfaces that typical plant and control room operators can easily master with minimal training.
Of course, site operators can make life much easier by opting for intelligent instruments and systems that comply with a leading international standard. The most popular option in the process industries is 4-20mA HART communications protocol, but digital alternatives such as Profibus and Foundation Fieldbus also have their supporters.
The results of the benchmarking survey suggest that this is likely to continue, with almost 4 in 10 operators expecting to use HART in the future, almost a quarter preferring the prospect of Profibus and around 1 in 10 saying they’re most likely to adopt Foundation Fieldbus.
The rise of wireless technologies is also making it easier to engage plant-wide communications, and some 23% of respondents say they see it as the way forward. It’s just as important for a wireless solution to be properly standardised as it is for wired schemes, and that recently got easier with the introduction of WirelessHART (IEC 62591, EN 62591), which gives users even more ways to get connected.
WirelessHART, the first interoperable wireless communication standard for process industries, builds on the existing foundation of HART, enabling users to tap into the benefits of wireless automation while ensuring that new systems are compatible with their existing devices, tools and systems. This will enable major cost savings, since it eliminates the time and effort associated with installing the cabling for conventional wired solutions. It can cut the time needed to configure new instruments within the plant-wide network by a quarter. On the downside, wireless connections are still relatively slow, making them unsuitable for relaying real-time data, so they can’t yet replace wired alternatives in every application.
Of course, the other big benefit of wireless is that it can improve health and safety still further, minimising the work needed to install an instrument at height, for example.
The extent to which plant operators are embracing smart technology varies enormously, in part because the age and condition of their current crop of control instrumentation will determine how much investment is needed. However, the situation is changing gradually, with over half of the companies in the benchmarking survey reporting that their control systems are already over 10 years old.
Health and safety has come a long way in recent decades, but every accident is still one too many. The pressure continues to find ways to get even better, and intelligent instrumentation can provide valuable tools to support that effort.
Companies looking to see how they measure up against their peers can use ABB’s online benchmarking tool to check how they’re performing. The free tool is available online at www.howdoyoumeasureupabb.com.
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