The Dolphin LM is a series of single-stage liquid ring vacuum pumps. An eccentrically mounted impeller rotates in a housing partially filled with operating fluid. The impeller blades dip into the fluid, and the centrifugal force exerted by their rotation forms a so-called liquid ring within the housing. The pumped medium is transported in the spaces between the blades and the liquid ring.
The eccentric rotation of the impeller alters the volume of these spaces, causing gas to be drawn in, compressed and expelled. Operation as a compressor is possible up to 1.5 bar(g). Dolphin LM 0100 – 0270 A are the three smaller vacuum pumps in a series that comes in a total of five sizes.