Tank Trailer Vacuum Collapse
Process tanks and vessels can withstand internal pressures much larger than the vacuums needed to collapse them. Such tanks and vessels are often collapsed when they are emptied without proper venting, or when their vents are obstructed. It is also possible to collapse a vented tank, if it is filled with steam and cooled rapidly. Vacuum collapse of unvented process vessels is an occasional occurrence in the process industries. Properly vented vessels will not suffer vacuum collapse under ordinary circumstances. Vented tanks undergoing steaming have a greater risk of such vacuum collapse than do tanks undergoing other processes.
Full YouTube video here: