On Fri, 19 Dec 2008 16:16:44 -0000, "Andrew Mawson"
wrote:


Now I did work in an oil refinery where if they let the pipes cool it
got very expensive, as the tarry gunge set solid, never to move again
G

So would they actually have to cut away the pipes and replace or could
they get them clear somehow?

Dad mentioned something similar the other day. Apparently it's just as
inconvenient when a ship hold (Shell tankers in his case) full of
something that should be liquid (like pitch or tar I think he said)
goes solid.

They normally pumped steam through pipes in the tanks when the sea /
outside temp dropped below a certain point and this would keep the
cargo liquid. However if the heating system failed (or they forgot to
turn it on) and the cargo did go solid, the steam heating system
wasn't able to take it back to liquid again (poor convection) and it
would all have to be cut out by hand. :-(

T i m