How does the seal work on a large resealable high pressure vessel such as an autoclave? example: http://gust.engin.umich.edu/autoclave2.jpg [Broken] If you look at the example above you always see the rotatable bayonet ring attached to the vessel. The red ring is probably the o-ring face seal on the chamber. The concentric rings on the end I assume are for thermal insulation of the red o-ring seal on the vessel. Is it the wedging of the bayonet ring that provides the normal sealing force or is there something that I'm missing? And how is that ring secured to the vessel itself while being rotatable and stiff enough to support all the pressure on the flange while in operation? Or is the flange the rotatable part (that would make more sense)?