This standard specifies the product classification, technical requirements, test methods, inspection rules, signs, packaging, transportation and storage of malleable cast iron pipe fittings (hereinafter referred to as "pipe fittings"). This standard applies to pipe fittings connected to general pipelines with nominal diameter (DN) 6-150 for transporting water, oil, gas and steam. It is designated to be connected with the thread in accordance with GB/T 7306. When used outside the specified pressure and temperature range, consult with the manufacturer.