GB/T 21386-2008 Ratio pressure reducing

GB/T 8464-1998 Valves with female screw ends for water-heating system GB/T 7306.1-2000 Pipe threads with 55 degree thread angle where pressure-tight joints are made on the threads—Part 1:Parallel internal and taper external threads GB/T 7306.2-2000 Pipe threads with 55 degree thread angle where pressure-tight joints are made on the threads—Part 2:Taper internal and external threads GB/T 9113.1-2000 Integral steel pipe flanges with flat face or raised face GB/T 9124-2000 Specification for steel pipe flanges GB/T 9124-2010 Specification for steel pipe flanges GB/T 9124.1-2019 Steel pipe flanges—Part 1:PN designated GB/T 9124.2-2019 Steel pipe flanges—Part 2:Class designated GB/T 12224-1989 General requirements for industrial steel valves GB/T 12224-2005 General requirements for industrial steel valves GB/T 12224-2015 General requirements for industrial steel valves GB/T 12225-1989 General purpose industrial valves—Specification of copper alloy castings GB/T 12225-2005 General purpose industrial valves—Specification of copper alloy castings GB/T 12225-2018 General purpose industrial valves—Specification of copper alloy castings GB/T 12226-1989 General purpose industrial valves—Specification of flake graphite iron castings GB/T 12226-2005 General purpose industrial valves—Specification of flake graphite iron castings GB/T 12227-1989 General purpose industrial valves—Specification of spheroidal graphite iron castings GB/T 12227-2005 General purpose industrial valves—Specification of spheroidal graphite iron castings GB/T 12229-1989 General purpose industrial valves—Specification of carbon steel castings GB/T 12229-2005 General purpose industrial valves—Specification of carbon steel castings GB/T 13927-1992 Pressure testing for general purpose valves GB/T 13927-2008 Industrial valves—Pressure testing GB/T 13927-2022 Industrial valves—Pressure testing GB/T 15530.1-1995 Cast copper alloy integral flanges GB/T 15530.1-2008 Cast copper alloy integral flange GB/T 15530.8-1995 Specifications for copper alloy and composite flanges GB/T 17219-1998 Standard for safety evaluation of equipment and protective materials in drinking water system GB/T 17241.6-1998 Integral cast iron pipe flanges GB/T 17241.6-2008 Integral cast iron flanges GB/T 17241.7-1998 Specifications for cast iron pipe flanges JB/T 7928-2014 Industrial Valve Supply Requirements JB/T 7928-1999 JBT 7928-1999 General valve Supply requirements JB/T 308-2004 Valves model designation method GB/T 17219-2025 Hygienic safety evaluation of distribution equipment,protective materials and treatment materials in drinking water system GB/T 12226-2025 General purpose industrial valves—Technical specification for gray iron castings GB/T 12227-2025 General purpose industrial valves—Technical specification for ductile iron castings GB/T 12229-2025 General purpose industrial valves—Technical specification for carbon steel castings