Grace's Guide is the leading source of historical information on industry and manufacturing in Britain. This web publication contains 129,283 pages of information and 204,290 images on early companies, their products and the people who designed and built them.
1906 Private company Bryan Donkin and Clench was renamed as Bryan Donkin Co Ltd.
The business was originally established by Bryan Donkin (1768-1855).
1910 Bryan Donkin Co began the manufacture of turbo-exhausters and blowers based on the Rateau principle.
1914 Gas, mechanical and motor engineers. Specialities: gas exhausting plants, high pressure gas plants, Rateau gas fans, gas valves of all types, reducing governors, tar and liquor pumps, motor parts made for the trade. Employees 700. 
1920 Issued catalogue on diaphragm gas regulators. The company is of Chesterfield. 
c.1928 Various engines for the Bath Gas Works, North Engine House.
1949 B. H. D. Engineers formed as a public company to acquire Bryan Donkin and Co and W. C. Holmes and Co, to carry on business as mechanical, chemical and gasworks plant engineers and ironfounders.
1961 Engineers and iron founders, manufacturing high pressure gas plants, compressors, valves, regulators, governors and pumps. 
1973 Hanson Trust acquired B.H.D. Engineers
--- of Lincoln (or does this refer to Lincoln Works?)
1961 Engineers and ironfounders, manufacturing high pressure gas plants, compressors, valves, regulators, governors and pumps. 1,000 employees.
1988 James Howden and Co acquired Bryan Donkin Blowers.
Bryan Donkin Valves Ltd of Chesterfield is now owned by the AVK Group founded in Denmark by Aage Valdemar Kjaer. AVK UK website