With lengthy and complex airport hydrant systems, detecting fuel leaks and other instabilities might seem like a daunting dilemma. On top of that, an airport that never sleeps doesn’t necessarily have the ability to shut down their fuel lines for inspection when planes are taking off nearly every hour.
Dean Golba, Head of Aviation at Atmos International (Atmos), said a better way to approach the issue is by thinking in terms of mitigation rather than prevention.
“We can't prevent leaks, and trying to prevent leaks is pretty much impossible, but mitigating the effects of leaks is the key,” Golba said. “Mitigation through regular testing is one way of doing things. The United States Environmental Protection Agency (US EPA) highlights this in the sense that they change the minimum detectable leak sizes based on how regularly you test. So, if you test annually, it's going to be a certain size of leak that you must detect. If you test biannually, then the size of leak slightly increases and it allows you for a little bit more leeway.”
Founded in 1995, Atmos has been developing leak detection technologies for use wherever pipelines are found.
“Oil, gas, chemical, water, aviation and mining industries, anything that has a pipeline involved we can work with it. We can detect leaks, simulate pipelines and apply various technologies,” Golba said, adding that Atmos technologies have been applied to over 1,500 pipelines globally in 60 different countries.
Challenges with leak detection on airport hydrant systems
Airport hydrant systems are unique among the other pipeline systems that Atmos works with, Golba said that, for example, a cross country pipeline leak detection system works on the basic principle that what goes into the pipeline must come out of the pipeline and this is always metered, be it with various number of inlets and outlets. Hydrant systems however have many pit valves (refueling points) and it would be very expensive to meter each and every one of those pit valves in order to apply a flow balance-based leak detection system.
“What's going in isn’t typically measured by custody transfer flow meters. How much fuel is then pumped into an aircraft is metered, however this is done locally on a hydrant dispenser or fuel cart, for the purpose of the aircraft and is not useful in any way in terms of providing leak detection. Those numbers are never really challenged against each other in a way that could provide highly accurate leak detection,” Golba said.
What that means is that commonly used technologies across other industries can’t be applied to aviation, resulting in much more specific test-oriented products being developed for use at airports.
Tightness monitoring development by Atmos
“Over the years we've developed an advanced system that specifically tests aviation hydrant systems by monitoring the pressure under various conditions. And the way we do that is to shut the hydrant system in. So, we lock the pressure into the pipeline, and test over a period of time. This was originally a 45 minute period, but we have now been able to reduce that down to only 15 minutes”, Golba said. “After that 15 minutes, we can then tell you whether there is a leak on the pipeline or not. The size of that leak can be very small.”
Golba said that while more and more airports are using an automation system (SCADA) that controls the hydrant, this has historically not been the case – especially in North America, where many hydrant systems were built before such technology existed. For hydrants lacking in automation, it’s very difficult to install a leak detection system without investing in a SCADA system, thus a standalone and portable solution was devised.
“It's called the Atmos Portable Tightness Monitor (APTM). The system has been developed for airports that don't have any level of automation, specifically smaller airports or older airports, airports that typically wouldn't have the budget to put an automation system with leak detection on the pipeline," Golba said.
“However, it became increasingly obvious in certain areas around the world that a portable system was actually a much more attractive proposition.”
If a SCADA system is in use on the hydrant, Atmos Tightness Monitor would be the best solution as this communicates with the SCADA directly and works hand in hand. Both products utilize the same highly accurate algorithms enabling detection of very small leaks.
How It Works
Golba said that a key feature of the APTM is the short time it needs to run its tests, now at 15 minutes.
“Testing time has always been a difficulty, there's a lot of airports around the world that operate 24 hours a day, seven days a week. For example, there are various airports in India that do not shut down and do not have curfew hours. Finding a 45 minute window for us to test is practically impossible in some locations. So, having reduced the testing time down to 15 minutes over the past couple of years, has really improved the ability to conduct these tests on hydrant systems,” he said.
The APTM uses the pressure step method, which works by testing a hydrant system at two pressure thresholds. First at its operational pressure, for example 170 PSI, and then after depressurizing, at a lower pressure, for example 100 PSI. Running the test at different pressure levels helps to negate the effects temperature can have on a test – such as falling pressure levels due to falling temperatures.
“The benefit of the pressure step method is that we're giving the customer a much more reliable result, a more repeatable result and also providing higher levels of accuracy,” Golba said.
Each APTM is calibrated and fine-tuned for the airport it is to be utilized by.
“We commission the system and tune it for each and every individual segment on a hydrant system. And that's how we get the best performance out of the system,” Golba said.
The APTM is small enough to fit into the trunk of a car or bed of a truck, making for easy transportation around the airport apron and does not require multiple people to operate or transport the system.
“The system itself is provided in two PeliTM cases, with the first containing a computer unit and the second the APTM depressurization manifold. The only other thing required is a support vehicle with a 12v DC outlet to power the system,” said Golba.
Maintenance and support
An APTM can be supplied with annual support and maintenance coming in the form of Atmos Aviation Care. Under this contract, all data is collected, transmitted to the Atmos Cloud and analyzed by Atmos engineers thanks to 4G communications built into it.
“Through Atmos Aviation Care, we can support the customers (often live) while they're doing the testing and in the event that they have any concerns over the data, we can almost instantly confirm whether the results are of any concern, whether we think there may be a passing valve on the hydrant system that needs to be investigated or maybe there's something else happening,” Golba said.
The visibility ensures tests are being performed correctly as Atmos engineers can view the process remotely as it is performed.
“If we see any drift in the data, we can investigate that. We can look at it instantly and we can respond to the customers, ensuring that again, the system is doing what it should be doing and that we can trust the results,” Golba said.
“To support our customers, we also provide access to our online training platform which contains videos, tests and certificates to ensure all operators using the Atmos systems are trained to the required standard.”
Airport hydrant system leaks can have serious consequences such as damage to the environment and lost revenue due to downtime of fueling operations. Atmos’ tightness monitoring systems give operators the ability to test their hydrant system’s integrity to detect and mitigate leaks within 15 minutes.
