Hydrogen-ready pig tracking systems

In the transition to a net zero-emission energy system, hydrogen will play a major role. Large-scale hydrogen consumption will require a well-developed hydrogen transport infrastructure. However, the properties of hydrogen present some significant challenges.

Hydrogen molecules are smaller than those of natural gas. This means bypass, where the medium passes through or around the pig opposed to being an energising force behind it is substantially more likely. The effect of this is that whatever methods the operator uses to estimate pig arrival times will need adjusting. In the worst case, the chances of a stalled pig increase – heavy wall bends at river crossings for example will require additional differential pressure, but equally if the pig sealing design is not optimum and bypass occurs, hydrogen will be far less forgiving than natural gas. One way to mitigate this risk is by using pig tracking with an Electromagnetic (EM) pig tracking system.

Hydrogen is highly flammable, easily ignited and heats up when reduced in pressure. It is also highly prone to the possibility of auto-ignition of leaks and atmospheric vents. Online Electronics Ltd’s EM transmitters are fully ATEX, IECEx & UKEx Zone 0 certified and meet the IIC gas group requirements for hydrogen. Their design has been enhanced to ensure the electronics are not compromised by the smaller hydrogen atoms and possible explosive decompression of the seals.

Whilst the adoption of safety rated (ATEX or IECEx) EM receivers differ across varying geographies & operators, again the hydrogen molecule will play a role. Pig launcher & receiver isolation valves are the primary line of defence against the pipeline medium. Obviously, the area around a pig launcher or receiver is typically classed as Zone 1. Pipelines that are to be re-purposed having valves that were previously effective at holding & sealing against natural gas now will have a much greater foe. The use of appropriately certified EM Receivers (as well as any additional safety measures) should be considered.

Online’s EM Ex receiver is hazardous area zone 0 certified and is used for locating multiple lost or stalled pigs and tracking pigs fitted with any EM pig transmitters. It can also be used to confirm a pig has left or arrived at a particular location and for general monitoring of pig movements. The enhanced sensitivity permits the location of transmitters even within very heavy walled launchers/receivers, pipeline bundles or Pipe-in-Pipe. It can also be configured in a hazardous area via Bluetooth using the Windows or Android apps. The protection method used is Exia (intrinsically safe) which makes the unit light and very portable without the need for a separate antenna. It is certified for use worldwide and meets ATEX, UKEx and IECEx stringent requirements with no need for hot work permits and all the paperwork and time that entails, saving time and money.

Since Online’s EM Transmitters and Receiver are fully ATEX, IECEx and UKEx certified and meet the IIC gas group requirements that is mandatory for hydrogen installations, no additional costly certification is required – they already meet the current and future needs of customers on their transition journey.

Online Electronics Ltd’s EMRx Ex ATEX receiver