UNE-EN 1759-1:2005 Flanges and their joints. Circular flanges for pipes, valves, fittings and accessories, Class designated- Part 1: Steel flanges, NPS 1/2 to 24.
2005UNE-EN 1759-1:2005 Flanges and their joints. Circular flanges for pipes, valves, fittings and accessories, Class designated- Part 1: Steel flanges, NPS 1/2 to 24.