Reducing the chances of costly gas leaks

Gas leaks can potentially have a devastating cost in terms of lost production, damage to equipment, environmental pollution and human safety. Being able to detect and prevent such occurrences is therefore high on the list of priorities for operators of pipelines and other processing facilities, and recent technology developments – from the latest in detection equipment to cutting-edge valves and seals – are having a big impact on the industry.

To find out more about the ways in which these innovations are improving safety and enhancing throughput, O&G caught up with two leading industry figures to get their views. Martin Olesen of Gassonic A/S and Julian Taylor of Rupture Pin Technology provide their thoughts.

Martin Olesen is Managing Director of Gassonic A/S, the market-leading manufacturer of fixed ultrasonic gas leak detectors for the petrochemical industry. Olesen was pioneering ultrasonic gas leak detection in the middle of the 1990s when only conventional gas detection systems were available. Today, the ultrasonic gas leak detection technology is recognized worldwide as a strong alternative/supplement to conventional gas detectors for detection of hydrocarbon gas leaks.

A graduate of Purdue University, Julian Taylor worked as Chief Engineer for various companies before starting his own company, Taylor Valve Technology. He then later developed Rupture Pin Technology in 1986 to solve the many problems associated with rupture disks. He currently has over 100 patents issued and pending.

How have companies traditionally dealt with the risk of gas leaks and what are the limitations to these methods?

MO. Operators have traditionally based their fixed fire and gas (F&G) detection system on conventional LEL-based gas detectors. In indoor or closed modules these technologies may work fairly well. However, in outdoor ventilated areas these technologies have some imminent shortcomings. The problem is that in order for the LEL-based detectors to work, they need the leaking gas to build up an explosive gas cloud and come into physical contact with the detector. Due to changing wind directions and fast dilution of the gas, this can be highly problematic. It means that an explosive gas cloud can go undetected for a long time. Besides, these technologies are based on consumable parts, which mean that maintenance costs can be very high.

JT. A major cause of gas leakage has been the safety relief systems. A rupture disk, by design, will fail early and cause unnecessary fluid discharge wasting both money and time. Replacement of a rupture disk requires opening the process line. This allows the fugitive emissions to escape into the atmosphere or on the ground if liquid. This also offers an opportunity of exposure to the workers performing maintenance. In hazardous locations, environmental suits may be required along with the required documentation needed to report the incident. If the gases are toxic, disc replacement can be dangerous and the downtime costly. A rupture disk should never be used for toxic or flammable applications. Steps should also be taken to minimize flaring. Burner and flare failure is a major source of dangerous toxic pollution. A flare itself generates both CO and CO2 pollution.

What are the potential costs or risks involved in not fully addressing gas leakages?

MO. An explosive hydrocarbon gas leak can have devastating consequences. The immediate potential costs include loss of human lives and productive capacity disruptions and destruction. Besides, likely subsequent consequences include bad publicity and costs related to accident investigation and repairs/replacement of damaged equipment. Because of this, risk and hazard management seem to be key focus areas throughout the industry.

JT. The potential cost involves much more than just money. It is obvious that any gas leak is a potential danger for toxic exposure, explosion and pollution. Loss of life, destruction to storage facilities, equipment or plants must be prevented. In addition, environmental fines for leakage are becoming a concern as well.

How do technologies such as your own contribute to the industry’s worker-safety efforts?

MO. Ultrasonic gas leak detection provides instant detection of hydrocarbon gas leaks. Unlike the conventionally used technologies the gas does not need to build up an explosive cloud and physically reach the detector. This means that the operator can take immediate action before the hazardous situation escalates. Besides, as the only fixed gas detection system, the ultrasonic gas leak detection technology makes it possible to verify the detection performance during system commission by means of simulation of real gas leaks.

JT. All relief valves should have bubble-tight elastomer seals compatible with the process fluids. Rupture Pin Technology continuously looks for new applications that can utilize our technology to prevent leakage. The Rupture Pin Technology relief valve uses an elastomer seal that provides a Class VI bubble tight seal until the valve relieves at set point. The Buckling Pin Technology emergency shutdown valve isolates pressure to prevent releasing system fluid into the atmosphere and will protect the downstream equipment from upstream pressure.

The Rupture Pin Technology valve offers the ability to relieve and then be reset without exposing the gases to the worker or environment. The pin is external of all process and is not affected by process or ambient temperatures. It allows the process to work close to set point without concern of an early failure as the pin cannot fatigue. The allowed standard accuracy is +/-5 percent with the typical accuracy below +/-3 percent. It is possible to eliminate flaring all together when protecting downstream equipment from a pressure reducing regulator or valve failure that causes excess downstream pressure. A Buckling Pin Technology emergency shutdown valve can be installed for overpressure protection of the downstream equipment.

What factors are driving demand for your solutions? Have you seen any particular trends in demand?

MO. For obvious reasons, operators are generally looking at ways to reduce risk and increase the effectiveness of the plant safety system. Speeding up the response time is one of the key elements in achieving this. Another trend seems to be the implementation of more detection layers in the F&G detection design. This means that the industry is increasingly focusing on the suppliers’ ability to combine sensor technologies to design the optimal safety solution.

JT. There is a trend toward elastomer seals on relief valves that can offer bubble tight sealing to reduce product loss, toxic discharge and pollution. We have also seen a definite trend for replacing rupture disks with Rupture Pin Technology valves. Rupture disks are designed to fail early causing unnecessary downtime, product loss and pollution. Replacing the disks requires opening the line. There is also a trend towards the elimination of flare systems; pressure can be isolated with the installation of emergency shutoff valves to protect downstream equipment. In the case where you are protecting a vessel with an upstream emergency shutoff valve, you may need a small thermal relief valve at the vessel.

Technology in the oil and gas industry is constantly developing. How do you ensure your solutions are always at, or ahead of, the leading edge?

MO. Gassonic A/S is in continuous contact with operators and industry people worldwide to learn about new trends and to develop and evaluate ideas for new developments. One of Gassonic’s core values is to constantly optimize the detection capabilities of our products. The inclusion of the Senssonic self-test technology in our next generation ultrasonic gas leak detector, the Gassonic Observer, is a good example of how close cooperation with leading industry people led to new product developments. We will continue to pursue this.

JT. Rupture Pin Technology is actively investing money and research to develop stronger and more durable elastomers through the use of an aligned nano tube blended to enhance performance. Another goal is to increase the temperature range, high and low, of elastomer compounds. This effort will enable the Rupture Pin Valve to be used in applications where extreme pressures and temperatures currently limit the seals capabilities and application.