Moisture that carries over continuously from a rotary vacuum filter compels the use of a wet vacuum pump, because dry-type equipment would soon be disabled in such service.
During a process upset, such as failure of the filtrate pump, slugs of liquid can carry over into the vacuum system. A broken filter cloth can even admit chunks of filter cake.
EVP Liquid-ring vacuum pumpsurvives such abuse without suffering any damage. It may be sealed with any one of many liquids to assure compatibility with the gas or vapor being extracted.