This standard specifies the terms and definitions, typical structure, technical requirements, test methods, inspection rules, marking, protection, packaging, storage and transportation of steel pipe welded ball valves. This standard is applicable to steel pipe welded ball valves with nominal sizes DN15~DN50 and nominal pressure not greater than PN40; nominal sizes DN65~DN600 and nominal pressure not greater than PN25; applicable temperatures are 0℃~150℃ and applicable media are water and steam (hereinafter referred to as ball valve).