Draft Document – Stainless steel components for hygienic applications in the food and the chemical industries – Part 2: Flange connections
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 10/01/2016

Draft Document – Stainless steel fittings for the food and chemical industry – Part 2: Hygienic flanged pipe connection, short type
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 12/01/2008