scope:

NEN-ISO 7121 specifies the requirements for a series of steel ball valves suitable for general-purpose industrial applications. It covers valves of the nominal sizes - DN 8, 10, 15, 20, 25, 32, 40, 50, 65, 80, 100, 150, 200, 250, 300, 350, 400, 450, 500, and 600 (NPS 1/4, 3/8, 1/2, 3/4, 1, 11/4, 11/2, 2, 21/2, 3, 4, 6, 8, 10, 12, 14, 16, 18, 20 and 24), and is applicable to the following pressure designations: - PN 10; 16; 25; 40; 63; 100; - Class 150; 300; 600; 800; 900. It includes provisions for valve characteristics as follows: - flanged and butt-welded ends in sizes 15 ≤ DN ≤ 600 (1/2 ≤ NPS ≤ 24); - socket welding ends in sizes 8 ≤ DN ≤ 100 (1/4 ≤ NPS ≤ 4); - threaded ends in sizes 8 ≤ DN ≤ 50 (1/4 ≤ NPS ≤ 2); - body seat openings designated as full bore, reduced bore and double reduced bore; - materials; - testing and inspection.