Blind flanges are used for connection with fittings or flanged components in water supply, sewage, and natural gas systems. Material: carbon steel. Reference standard SR EN 10921-1 Flanges and their joints. Circular flanges for pipes, valves, fittings, and accessories, designated by PN. Part 1: Steel flanges. Explanation of terms in the designation: D = nominal outer diameter of the flange end with which the flange is compatible. DN = nominal diameter of the flange according to SR EN 1092-1, SR EN ISO 6708. Compatible with: PE100 PN16 flange ends, item codes 44411% and 45411%. Flat rubber gaskets, item code 44799%. Bolt set with nut and galvanized washers, item code 44798%.