What's the safest way to clean a Acetic Acid Pipe line of 100 meters of longitud, to cut with fire and repair?
Currently we clean the pipe lines getting them full with water, 30 tons/hr flowing to an a storage tank truck, around 30 minutes, after we use nitrogen to blow (7 bars) the acid and water to a tank truck.
We do this three times, to make sure the pipe line its very clean.
After that, we dry the line with air, 8 hours, then we seek LEL % whit a SIRIUS MSA device, if there is a 0.0 % LEL, we inject a inert chamber (using nitrogen very low pressure).
Then we make the first cut using fire.
We use nitrogen because its a inert gas and it displaces the air and so we prevent the formation of an explosive atmosphere.
If you have another practices or examples I'll be glad to learn.