Thread: Interesting, Odd or Funny Pics.

Originally Posted by p38arover

I wondered what would cause a vacuum sufficient to do that.

yep the steam out causes the air to rush out due to the heat expanding the air volume.

the cold rain hitting accelerates it dramatically, but can occur without the cold if the venting speed out exceeds the venting speed in. Lot's of youtube films of doing this to 44 gallon drums as a party trick. [ame=http://www.youtube.com/watch?v=7QV7rMqH_cY]Satsuma High School 5-6-2009 - YouTube[/ame]

I see this on big scale all the time as is a common mistake in the petro/chem business

Do we have a safety thread?

Originally Posted by fesm_ndt

yep the steam out causes the air to rush out due to the heat expanding the air volume.
That is true, but it is the next bit that is important, when the steam condenses, the air inside cools and contracts and the air pressure outside the tank crushes it.
the cold rain hitting accelerates it dramatically, but can occur without the cold if the venting speed out exceeds the venting speed in. Lot's of youtube films of doing this to 44 gallon drums as a party trick. Satsuma High School 5-6-2009 - YouTube

I see this on big scale all the time as is a common mistake in the petro/chem business

Do we have a safety thread?

If anyone had any doubts about the power of air pressure harnessed in that way, just remember that that was what provided the power in very early low pressure steam engines.