What is an expansion joints in the piping system in petrochemical co?

Expansion joints are designed to maintain the seal on a pipe system while the temperature varies. The temperature can vary due to the outside air temperature. In the morning the temperature could be 35 degrees F, but in the afternoon it could be 75 degrees F. The temperature can also vary by what is inside the pipeline -- from rinse water at 45 degrees F, to hot liquid at 200 degrees F a few minutes later. When the temperature changes the metal in the piping expands and contracts. 2 pipes joint together will want to separate when the 2 pipes contract, and they will want to bend when pushed together hard enough (when they expand at high temperatures). Expansion joints prevent pipes from pulling apart, or pushing together too hard. Flexible bellows also allow for expansion and contraction due to temperature, but there is another problem with pipe joints that makes them fail -- vibration. If there is some machinery that the pipe is attached to that is vibrating (like a rock crusher, or ...  more