Analysing the data from sensors attached to pipes and connectors helps keep process plants running safely, profitably, and at maximum capacity for longer, writes Robert Smith.
Process plants are immensely complex structures. From refineries and water treatment plants to offshore oil and gas platforms and food and beverage production lines, facilities within the process sector are superstars of the engineering industry.
They are purpose built to help convert raw materials into the everyday products we often take for granted. But these products are vital. This is why process plants must be meticulously designed.
Increasingly, companies are using more modern techniques (including 3D modelling software and virtual reality technology) to ensure everything from the instruments and electronics to equipment storage units are built in the most practical place.
It is vital that the piping that constitutes the plant is capable of withstanding the corrosion risk placed upon by those frequently corrosive process fluids
Using this technology also increases your chances of building a plant in the most efficient and cost-effective way, which, in theory, means you will run into fewer issues further down the track.
But none of this will matter if you fail to get the fundamentals right. This is why something as innocuous as pipework is so important to the process industries.
At the heart of most facilities is a network of pipes and connectors used to contain and transport the various process fluids into, throughout, and out of the plant. Often overlooked, pipes and connectors play an absolutely vital role in the process industries.
Making sure they are well looked after should be a top priority for any plant operator.
Stress test
Unfortunately, while pipes and connectors are often exposed to temperature changes, vibrations and a variety of other stresses, it has traditionally been difficult to monitor their condition.
“Given that many process fluids are extremely valuable and often hazardous to people and the environment, it is vital that the piping that constitutes the plant is capable of withstanding the corrosion risk placed upon by those frequently corrosive process fluids,” explains Jake Davies, global marketing director, Permasense at Emerson Automation Solutions.
“Loss of containment can result in considerable unplanned downtime, expensive repairs and major incidents such as fires or serious environmental damage,” Davies says.
It is therefore essential to have accurate insight into the state of pipework to help monitor whether it is capable of handling the ever-changing corrosion demands being placed upon it from the inside.
Traditionally to get this information, technicians would check the remaining thickness of piping using handheld equipment.
However, the difficulty and cost, and sometimes safety risks, associated with taking these measurements, especially in difficultto- reach parts of the plant, means that the data recorded is very sparse. Typically, a location will be measured every few years, Davies says.
To make matters worse, more conventional equipment can struggle to provide the insight process operators typically require.
Data drive
Fortunately, within the last decade, sensors that are left attached to pipes, but do not intrude through the piping, have become increasingly popular, especially in the oil and gas and refining industries, Davies says.
“These sensors continuously monitor the thickness of the piping and send this data wirelessly to the desks of the engineers who use it to ensure the pipe is withstanding the corrosion demands.
“In turn, this data enables better decision making about how to run the plant – what feedstocks to process, optimisation, corrosion inhibition optimisation and better-planned maintenance and shutdowns.”
But how exactly are companies using this data to reduce downtime, improve production, and keep processes going for longer – and, importantly, what are the benefits?
Having continuous pipe thickness data sent automatically to the operations desk in real-time enables operators to drive the plant to its maximum capability, Davies adds.
“If high-wear conditions are detected, then action can be taken quickly and with the plant online to avoid any unplanned outage or leak. Alternatively, if the piping is experiencing a lower corrosion or erosion rate than anticipated, then the operator may be able to extend the run length of the plant, delaying a planned shutdown until later, safe in the knowledge that the piping is in a good state.”
Online corrosion monitoring will deliver data to increase plant availability, productivity, safety and ultimately profitability
Jake Davies, global marketing, Permasense at Emerson Automation Solutions.
One of the most common-use examples of this technology is to validate that corrosion rates do not exceed tolerable levels when a change in process or feedstock is planned.
For instance, a typical refinery could save around $5 million (£3.9m) per year by buying cheap ‘opportunity’ crudes, Davies explains. However, these cheaper crudes often contain a higher level of corrosive contaminants, meaning they bring additional corrosion risk into the refinery.
“By monitoring the thickness of the metalwork and other fixed equipment in certain key areas of the plant, operators can validate that the plant is capable of enduring this additional corrosion load and determine instantly if the risk outweighs the plant’s corrosion resistance capability, taking appropriate action to avoid any major damage to the plant.”
Another common example can be seen when operators are trying to avoid unplanned outages in areas of the plant that are exposed to high levels of corrosion risk. According to Davies, the cost of pro-actively replacing equipment versus unplanned replacement typically incurs costs in the region of hundreds of thousands of dollars. Clearly, every day that a process plant is not running, due to corrosion related downtime is a day that the plant is not creating profit – potentially millions of dollars per day.
“Online corrosion monitoring will deliver data to increase plant availability, productivity, safety and ultimately profitability,” Davies says.
Tech savvy
Fortunately for today’s engineering firms, there is now a broader selection of technology that helps monitor pipes and connectors and provides valuable insight to keep production lines running.
Emerson’s portfolio of corrosion and erosion monitoring solutions includes the Rosemount Wireless Permasense sensors range – designed to monitor the thickness of the piping, more traditional inline probes to monitor the corrosivity of the fluids themselves, and a variety of other fixed monitoring equipment.
Davies says that by combining the data from inline probes to monitor the risk of corrosion damage with non-intrusive thickness sensors to monitor equipment integrity, engineers can generate a complete set of data with which to better operate the plant.
“By utilising these technologies, plant operators can also manage the variability in corrosion risk over time that is experienced within a typical process plant. Data from both the probes and the sensors can be retrieved using WirelessHART solutions,” Davies says. This, he adds, is designed to help ensure reliable data delivery to the desk and significantly reduce the cost of system installation because no cabling is required.
“Data visualisation and analysis software also allows the plant operator to work with the data intuitively and quickly, enabling them to focus their efforts in making decisions about safely driving the plant to its maximum capability and profitability.”
