Birger and Fredrik Ljungström were among the many major Swedish inventors around the turn of the century. In 1908 AB Ljungströms Ångturbin (ALÅ) was established to exploit the double-rotation steam turbine, invented by Birger Ljungström.
Licensed production of the Air Preheater for stationary installations commenced during the 1920s. Svenska Maskinverken, James Howden & Co and The Air Preheater Company Inc. were the first licensees.
During World War II an extensive development program on behalf of the Swedish Defence Forces included projects involving missiles, athodyds (air thermo dynamics, ram-jets), turbo-superchargers ducts and torpedoes. In 1950 the remaining patents for steam turbines were sold to Stal which was later merged with the De Laval Steam Turbine Company to form Stal-Laval, today ABB Stal. In 1951 the name of AB Ljungströms Ångturbin was changed to Svenska Rotor Maskiner AB (SRM). Until 1981 SRM was listed on the Stockholm stock exchange. In 2003, SRM was acquired by Opcon AB that was listed on the Nasdaq OMX stock exchange.
In 2015, SRM and its sister company Opcon Energy System AB (OES), with the holding company owning them, Opcon Compressor Technology AB, were acquired by the Chinese Fund Shanghai XingXueKang Investment Partnership.