工业通用钢制球阀

[中文适用范围]： 本国际标准规定了一系列适用于通用工业应用的钢制球阀的要求。这些阀门的公称尺寸为DN8,10,15,20,25,32,40,50,65,80,100,150,200,250,300,350,400,450,500和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和24），适用于以下压力等级：PN10,16,25,40,63,100；以及Class150,300,600,800,900。注意，阀门特性不一定在所有公称尺寸和压力等级下都可用。例如，Class800仅适用于螺纹端和插座焊接端的DN≤65（NPS21/2）；而Class900仅适用于缩径阀体座开口。本标准包括以下规定：法兰和对焊端接头（DN≥15至DN600，NPS≥1/2至NPS24）；插座焊接端接头（DN≥8至DN100，NPS≥1/4至NPS4）；螺纹端接头（DN≥8至DN50，NPS≥1/4至NPS2）；阀体座开口标记为全径、缩径和双缩径；材料；测试与检验。 [外文原描述]： ISO 7121:2016 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. NOTE Valve characteristics are not necessarily available in all nominal sizes for all pressure designations. For example, Class 800 applies only for valves with threaded end and socket weld ends up to DN 65 (NPS 21/2) and Class 900 applies only for reduced bore body seat openings. 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.