Can digestion vessels be left assembled overnight?

No. The digestion vessels must not be left assembled for extended periods of time (e.g. overnight). If digestion vessels are left assembled for extended periods of time, the O-rings in the vessel bottom assemblies will deform and future integrity could be compromised. If digestion vessels have been left assembled overnight, disassemble them and allow them to reshape for an hour before use.  It is very important to thoroughly clean the digestion vessels and vessel bottom assemblies after use. Use water, and NOT ethanol or acetone, as the final rinse solution.