[OT] Safety when purging gas pipes

[Mike]

Drivel gone on a holiday overseas or are catastrophic floods more his line?

[cynic]

I wonder what the truth of the matter is? In the UK non domestic purging is strictly controlled and with pipes of the size indicated would normally be air - inert gas (usually Nitrogen) - combustible gas to prevent any possibility of an explosive mixture within the pipe. Speed of purging (velocity within the pipe) is also critical so as to minimise mixing or diffusing at the interface. If the Merikans have similar standards it may be that someone cut corners. I wouldn't worry about it happening over here with trained operatives.

[Mike]

I wouldn't be so sure. Most of the gas fired power plants built over here have used extensive overseas expertise for the fiddly technical bits and with local labour for the heavy work like civils. Maybe the H&S culture over here *where it is needed* is different to the USA. IN the past we certainly appeared to do things in a safer manner than some of the Europeans.

Something unplanned has happened though, so it does point to a process failure of some kind mainly because you don't use amateurs to perform work like this and as you say there would be careful control of the purging.

Do you know if they would they use flame traps or if they would be effective?

What is surprising is the number of people who were on the site during activities of this nature and that they had considerable difficulty in finding out how many persons/bodies they were looking for.