Glandless pumps or Canned rotor pumps have been used in the heating and air conditioning industry for many years. The design principle has not changed much over the years with the pumped liquid lubricating the pump bearings and the pump rotor being sealed within a can. The motor stator is the other side of the can, protected from the pumped liquid. This results in the pump being known as a Glandless Pump. Since 2013 all common Glandless pumps must have integrated energy-saving inverters and are normally single phase.