Industry Standard of the People's Republic of China HG/T 21576-94 Double Switching Plug Valve 1994-12-09 1995-01-01 Ministry of Chemical Industry of the People's Republic of China Industry Standard of the People's Republic of China Double Switching Plug Valve HG/T 21576-94 Editor: General Research Institute of Science and Technology, Ministry of Chemical IndustryApproval department: Ministry of Chemical IndustryImplementation date: January 1, 1995 Editorial Center for Engineering Standards, Ministry of Chemical Industry Document of Ministry of Chemical Industry Chemical Construction Development (1994) No. 842 Notice on Issuing Two Chemical Industry Standards, namely "Double Switch Plug Valve" Chemical Industry Departments (bureaus, companies) of provinces, autonomous regions, municipalities directly under the Central Government and cities with independent planning status, and all relevant design units: The two standards, namely "Double Switch Plug Valve" and "Quick Special Pipe Connector", formulated by the General Research Institute of Science and Technology, Ministry of Chemical Industry, have been reviewed and approved as chemical industry standards, with the numbers HG/T2157694 and HG/T 21577-94 respectively. They will be implemented on January 1, 1995. The two standards are managed by the Chemical Process Piping Design Technology Center of the Ministry of Chemical Industry and published by the Engineering Construction Standard Editing Center of the Ministry of Chemical Industry. Ministry of Chemical Industry December 9, 1994 Subject content and scope of application Referenced standards Code and symbol Main technical parametersbzxZ.net Structural features, types and dimensions Technical conditions Preparation instructions 1 Subject content and scope of application 1.0.1 This standard specifies the structural type, dimensions, technical parameters and technical conditions of double-switch plug valves. 1.0.2The biggest feature of this valve is that when the valve is overhauled, the valve body can be disconnected to replace the valve core without closing the upstream valve to avoid affecting other users. This has certain advantages for public engineering pipe networks and pipeline systems with many branches. 1.0.3This standard is applicable to general industrial equipment and pipelines that transport water, steam, oil and acid media. The valve body is carbon steel and is suitable for water, steam, oil and other media. The valve body is stainless steel and is suitable for acidic media. GB979 GB2100 JB/T5100 GB1184 GB4334 GB 4981 GB12225 GB5679 GB7T 12252 116. 5 GB 9116. 8 Referenced standards "Classification and technical conditions of carbon steel castings" "Technical conditions for stainless acid-resistant steel castings" "Technical conditions for investment casting carbon steel parts" "Shape and position tolerances, provisions for unmarked tolerances" "Intergranular corrosion tendency test for cast stainless steel" "Pressure test for industrial valves" "Technical conditions for general valve steel alloy castings" "Mallet cast iron" "General valves Marking" "General valves 1 Supply requirements" "Solid face with neck flat welded steel For example: DBP50-SI.G. 3. Code and mark: Valve body material: Nominal pressure: Connection type: Nominal diameter: Product code: G: Cast steel: P: Stainless acid-resistant cast steel: S: Pipe thread: F: Flange: [Double Block Plug Valve: (Double Block Plug Valve)]: Indicates a double-switch plug valve with a nominal diameter of 50 mm, pipe thread connection, a nominal pressure of 1.0 MPa, and a valve body material of cast steel. 3 4 Main technical parameters 4.1 Nominal diameter and nominal pressure Threaded double switching plug valve Nominal diameter: DN15-50mm, Nominal pressure: 1.0MPa. Flange-connected double switching plug valve Nominal diameter: DN25~80mm; Nominal pressure: 1.6MPa, 2.0MPa. 4.2 Working temperature When the inner core material is nylon 1010, the working temperature is ≤80C. When the inner core material is polytetrafluoroethylene, the working temperature is ≤150C. 4.3 Main materials See Table 4.3.1 for the main materials. Parts name Flip body, gland, Outer core, cap Cast steel RZG200-400 Cast stainless steel ZGOCr18Ni9 Copper alloy 2QSn5-5-5 Cast stainless steel ZGOCr18Ni9 ZG1Cr13 ZG2Cr13 Polytetrafluoroethylene, nylon 1 010 Mallet cast iron KTH330-08 Standard number JB/T5100 GB2100 GB12225 GB2100 GB5679 Structural features, type and size Connection points Double switching plug valve is a double rotary valve. In normal production, both valves are open. If the rotary core is disconnected, the internal gear can be replaced, so it can be repaired in the running state. Connection type 5. 1. 2. 1 Butterfly connection Threaded connection double switching valve see Figure 5.2.1. Figure 5.2.1 Flange-connected double-switch plug valveSee Figure 5.2.2Figure 5.2.2 5.3Dimension table Threaded double-switch plug valveSee Table 5.3.1Nominal diameter Nominal pressure Thread G Flange-connected double-switch plug valve: 5.3. 2. 1 Nominal diameter Flange PN1.6MPa, standard number GB9116.5, see Table 5.3.2.1. Table 5.3.2, 1 Nominal pressure Nominal diameter Flange PN2.0MPa, standard number GB9116.8, see Table 5.3.2.2. Table 5.3.2.2 Nominal pressure Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.