Suspected Gas Escape Identification
Gas utilities globally receive thousands of suspected gas escape reports from members of the public (PRE’S) each day. Most are found and resolved within a few hours, but occasionally PRE’s take weeks and even months to resolve. Substances such as petrol, kerosene, liquid petroleum gas (LPG), mine drainage gas, bio-gases from landfills – sewers and bio-digesters, paint thinners, foam blowing agents etc – can all confuse the unsuspecting gas tester. Finding gas leaks at the best of times isn’t simple, but here at @gt we provide simple tool to make things easier.
What’s the Problem?
As already stated, being called to a suspected gas escape is routine for First Call Operatives (FCO’s) around the world. But knowing and finding the source of flammable gases isn’t always straightforward! In the past we have been called to help investigate PRE’s that have taken over a year to resolve! For example, when natural gas leaks into a sub-terrain void over many years, a large reservoir of flammable gas can accumulate taking many months to ventilate. Assuming the gas transportation company has found and repaired the leak (and this is not always the case as there may be more than one leakage point), the immediate temptation is to assume the natural gas will quickly ventilate to zero. When this doesn’t happen, it is easy to imagine the flammable gases are from another spurious source such as a coal mine, landfill or naturally occurring deep down in the surrounding earth!
Now you may be thinking “we wouldn’t be tricked” but trust me, all transportation companies will at some time or another come across a very unusual set of circumstances which lead to large investigations and mounting costs. Let me give you just one more example from our vast experience to illustrate.
A dog walker in the countryside finds a smelly gas bubbling up from the ground in a field. She reports this to the local gas emergency service who send an FCO to investigate. The FCO finds a flammable gas in percent volume concentrations and reports his finding back to the Control Room. Further investigation indicates a high pressure (> 7 bar) pipeline is within a few meters of the gas escape. The incident is now escalated, and transmission engineers dispatched. In the meantime, Grid Control and senior management set about devising a plan to de-pressurise the pipeline to facilitate a repair.
Ask yourself – what would you do in these circumstances?
Fortunately, while this was happening, one of my chemists was dispatched to sample the gas and bring it back to the laboratory for analysis. The analysis found it to be a biogas and not natural gas as transported by the transmission company. So, what now?
Well the landowner was contacted and admitted to burring an old crop of sugar beat in the field some months earlier. These had been slowly breaking down in the soil to produce the biogas. Problem solved, and major emergency avoided!
Do you get the point?
“The ability to quickly identify the source of flammable gas readings in properties and roadways is essential for those organisations involved in gas transmission and distribution!”
So here at @gt, we offer a quick and simple service to train workers in the sampling and identification of flammable gases and thus identifying the source of public reported gas escapes. We teach our learners to be observant testers, how to recognise the potential for alternative flammables to natural gas and where to go for further assistance if needed.
We also provide a comprehensive service of sampling and identification for those who need it. Using tried and tested methods of identification, we can tell you on site if needed whether the gas is yours and if not, what its probable source is.
How’s It Done?
The process of identifying suspected gas escapes is relatively straightforward. You need to establish primarily what is being transported within the gas distribution network and compare it with what is detected by the FCO. Simple? Well yes, if you have access to a gas chromatograph (GC- Is a laboratory instrument which splits the sample into its individual components allowing the analyst to determine its nature and source). However, even with analytical support, a definite identification isn’t always simple. Many gas transporters now distribute gas from multiple sources, for example:
- Natural gas from different fields and countries
- Liquefied natural gas (LGN)
- Substitute natural gas (SNG)
- Bio-gas and bio-methane
- Liquid petroleum gas (LPG)
So – knowing for sure what the source of the leak is from composition alone, is getting ever more complicated. And that’s why we have developed a new course to teach transporters what to look for and how-to speedup the identification process.
Can Gas Identification be Performed onsite?
Yes – fortunately there are a number of new portable analytical tools to do so. These are not cheap to purchase but pay for themselves very quickly. Part of our training covers the selection and use of analytical tools and how a range of standard portable gas detectors, sensors and filters can help in the process. It also considers the use of tracer gases and odorants and how these can help and hinder the unsuspecting FCO.
The Future for Suspected Gas Escape Identification.
The future of gas escape identification lies very much in the hands of the transporters. Currently there is little formal training on this subject and we think @gt are the first to offer a specific course on the subject. The alternative is to rely on expensive, outside consultants to provide the needed support when complicated situations arise and then only after days or weeks of investigating and mounting costs. The use of trained professionals with the right tools to provide onsite identification is the way ahead.
One final example of how such training could have helped identify the fire risk at Grenfell Tower can be seen at the following link. This example and many others demonstrate how gas testers of all types benefit from continual training and development. @gt does its best to keep you informed and up-to-date with the world of gas detection so watch this space and feel free to comment
Written by a former BG Scientific Officer.
We would love to hear your comments and questions on this and many other related subjects.
If you would like to know more, feel free to contact us.