Translation of IBS EN ISO 9809-1:2010- terminology problem 1

[Educationguy]

Hello,
I am translating BS EN ISO 9809-1:2010. It concerns gas cylinders. I need one small favour. Can you help me with this part:

" In cases where the base is suspected to be plugged, the section shall be etched after the first examination to
verify the absence of a plug. Plugged cylinders shall not be approved"

The whole pragraph is about a cylinder base examination after prototype testing and I could not find the correct explenation for the word plug/plugged when it is used like this. Can you help me to understand what does it mean when the steel/base is plugged?

Thanks,
Tom

 

[DekDee]

Tom,
I am not familiar with the code but I will hazard a guess. (based on different scenarios from other industries).
If a hole has been incorrectly drilled or cut in a pressure containing vessel a plug is then inserted and it is welded into the hole.
Once the weld is ground smooth you would never know a hole had been there (this can be especially hazardous if the weld is not sound because nobody knows what has happened - other than the person who did it).
By acid etching the weld metal will be easily defined (if it has been plugged) even though it is impossible to see with the naked eye.
Hope that helps,
Cheers,
DD

 

[Educationguy]

DD,
Thank you very much. Your post put me on the right track.

It helped a lot,
Regards,
Tom