History 1948 The company was founded in Wuppertal-Barmen by machine construction engineer Friedr. Wilh. Herberholz. Manufacture of hand-operated flow control valves to be welded in place for the heating industry. 1954 Production extended to include flow control valves for clamping between 2 flanges. Nominal diameters between 50 mm and 600 mm. 1956 Manufacture of flow control valves with flanges on both sides. 1957 80% of production was converted to the manufacture of special forged steel flow control valves for transformers. Pipe diameters were 80 and 100 mm. 1960 Automation of flow control valves with electric and pneumatic actuator systems began. Flow control valves as remote controlled regulator valves. 1967 The company moved from Wuppertal to Schwelm. Production of close-sealing valves began – shut-off valves initially with nominal diameters between 50 and 300 mm. 1976 Production of shut-off valves extended up to nominal diameter 500 mm with electrical and pneumatic actuators. 1980 Production extended to include closing flaps for hot air and exhaust gases up to 600 °C. 1981 The company's founder died in May 1981; his son, Günter, continued to manage the company. 1981 The company moved from Schwelm to its present site in Ennepetal. The production of shut-off valves with solid PTFE lining (patented) began. 1984 Standardisation of fitting dimensions begins. Production of special valves and safety valves. 1986 DVGW (German Technical and Scientific Association for Gas and Water) approval 1991 In July the company was taken over by Herr Mag. Manfred Gur of Vienna. The successful company retained its founder's name. 1993 Co-operation with a Hungarian production concern. 1995 The range of products was radically expanded to meet customers' needs. 1998 The company's 50-year jubilee was celebrated on the 1st August. 1999 Ownership passes to Ludwig Polsterer GmbH. 2002 Certification to DIN EN ISO 9001 : 2000 2004 Extension of the administration building. 2006 GOST Certification for series AK/DVGW, HRD/HRA and RD/RA