Pipeline Integrity: An update on safety management techniques

An update on safety management techniques

The integrity of pipelines is a basic concern for pipeline operators, and therefore the ability to detect anomalies due to corrosion, erosion, milling and mechanical damage is of significant interest to them. Proper pipeline integrity management can not only extend the life of existing pipelines but also help in preventing damage in the future, if undertaken during the design and construction of new pipelines. Over the years, several technologies have been adopted in the country to maintain the safety of the gas pipeline network.

Fire safety market

The country’s fire safety market is likely to surpass $4.26 billion in the next two to three years. Over the years, large manufacturing and industrial facilities have been adopting fire suppression products at higher rates. The market for fire suppressants can be broadly divided into three segments – water-based suppression systems, special fire suppression systems (making use of foam or dry chemicals) and gas-based fire suppression systems.

Gas-based suppression systems use gaseous agents to control or extinguish fires and are also called clean agent fire suppression systems. These offer several advantages over other alternatives in terms of competitive prices and do not cause any harmful impact to humans or the environment. These fire suppression systems are classified on the basis of suppression agents that are used in the system such as carbon dioxide, inert gases such as IG 55, and clean agents such as heptafluoropropane (FM 200) and fluoroketone (Novec 1230). End users in the country have adopted all three types of gas-based suppression systems. The adoption rate of one gaseous suppression agent over another depends on factors such as cost, protected space occupancy and the end user’s preference based on past experience.

Unlike most other extinguishing agents, these clean agents are not stored as pressurised gases, but as liquids, which instantly dissipate to form a gas when discharged from a properly designed system. Also, storage in liquid form has many benefits, one being that it can be easily transported in bulk, even by air. Further, refilling a system after discharge is much safer and simpler than working with bulk pressurised gas supplies and far more convenient than sending cylinders offsite. Finally, cylinders containing these fluids occupy less space than cylinders of carbon dioxide or inert gas systems. As these are formulated to extinguish by cooling, the fire is tamped down quickly, minimising the risk of spreading. Further, their non-corrosive, non-conductive properties allow them to be used to protect sensitive equipment such as those in telecom and computer installations. These clean agents have minimal impact with respect to environmental parameters such as ozone depletion potential, global warming potential and atmospheric lifetime.

Use of thermal imaging technology

Gas leakage is a hazard which can result in major accidents involving  human injuries and fires, as well as have a huge impact in terms of the costs involved. To avoid such situations, preventive inspections are of paramount importance. Since gas leakage is invisible  (due to the fact that the radiation emitted by the gases is invisible to the human eye), thermal imaging technology is used to detect and evaluate the severity of leakages.

Over the years, the thermal imaging technology has evolved to a great extent. From a technological point of view, any material which is above -273 °C emits infrared radiation. This infrared radiation is captured by thermal cameras, transformed into electric signals, and then converted into video signals. Thus, thermal cameras convert invisible infrared radiation into a visible image. This technology has revolutionised maintenance in several industries, proving to be the best technology for finding hidden electrical and mechanical faults, even before an accident occurs. The clear benefits of this technology have been substantial cost savings, increased worker safety and enhanced product and process quality. They are successfully used for detecting insufficient insulation in buildings (identified as one of the highest opportunity areas for decreasing the greenhouse gas effect) and in detecting environmentally dangerous gas leaks.

With regard to the oil and gas sector, this technology can be used extensively for predictive maintenance, fire prevention, firefighting, flare monitoring, tank level detection, and infrared windows. The thermal cameras have special filters in place for the particular gas which needs to be visualised. They also have cryogenic coolers which brings down the temperature within the camera to -198 °C and the detector starts receiving radiations which cannot be seen with the naked eye. Leaks as minute as 0.8 grams per hour can be visualised with the help of this technology. Therefore, it enables the leaks to be identified and fixed from a safe distance. The level of leakage taking place in the field can also be quantified with the help of a new attachment which can be added to the camera.

A major advantage of thermal imaging technology is that it provides a visualisation of heating up of systems, loose connections and minute changes in insulation without having to touch anything. Therefore, it ensures that operators have enough time to act and react before fires break out. As the technology also permits visibility through smoke, the identification of the source becomes much easier. Other advantages are that systems do not have to be shut down during inspection, measurements can be carried out remotely and rapidly, and, most importantly, problems can be identified at an early stage. Although invisible to the naked eye, a thermal imaging camera can monitor whether a flare is burning or not. The cameras recognise the difference in the heat signature of a flare stack flame and the surrounding background. In addition to detecting stack flames, these cameras can be positioned to monitor the igniter flame as well. If the flare is not burning, harmful gases can enter the atmosphere; in these systems an alarm can go off and immediate action can be taken. Typically, cameras are mounted on rigid structures in moisture-resistant casings to protect them from harsh weather conditions.

Further, this imaging technology can also be used for monitoring the level of liquid inside the tank from a safe distance, by using infrared windows which provide an inside view of the cabinet. The technology also has widespread applications in other industries, such as automotive, construction and building, medical, textiles and electronics.

Conclusion

Given growing safety and environmental concerns regarding pipeline management, operators are expected to treat pipeline safety and integrity as a social accountability issue and new initiatives with regard to the same have facilitated this move. The market for fire suppressants using clean agents in the oil and gas industry is bound to grow in the future as these have been specifically developed to combine performance, safety and ease of handling with an excellent environmental profile. Further, the thermal imaging technology has also provided an automated detection system by which gas leakages can be detected earlier and faster.

Based on presentations by Sahil Amla, Product Marketing Manager, Honeywell, and T.P. Singh, Director and Country Manager, Instruments, FRLIR Systems India, at a recent India Infrastructure conference