Our DVGW approved H-Elastic are used for drinking water and gas. Our H-elastic screwing is used for steel pipes according to DIN EN 20255 and is further drink water DVGW W534 and gas DIN3387 approved. The screwing body is produced out of high quality malleable cast iron, according to DIN EN 10242. Our conical special seat is manufactured from NBR with a thread according to DIN EN 10226. Standards: EN-GJMB 350-10, EN 1562 Materials: high-quality cast malleable iron (body & nut), NBR (conical seal), galvanized steel (washer), brass (clamping ring)