Chemical Industry Standard of the People's Republic of China Glass concentric reducer 1 Subject content and scope of application HG/T2138-91 This standard specifies the type, basic parameters, dimensions and technical requirements of glass concentric reducers. This standard is applicable to glass concentric reducers with a nominal pressure (PN) equal to or less than 1.0MPa and a medium temperature of -20℃ to 200℃ for type A reducers and -107 to 200℃ for type B and type C reducers. Reference standards Tolerance and fit Limit deviation of dimensions without tolerance GB1804 Hexagon head bolts, grade C GB57802 GB5782 Hexagon head bolts, grade A and B GB6 1701 type hexagonal nut, A and B grade GB9439 gray cast iron parts ZBG94004. Technical conditions for glass equipment HG/T2105 slip-on flanges for glass equipment 3 types, basic parameters and dimensions 3.1° slip-on flange connected steel glass concentric reducer (type A) according to the provisions of Figure 1 and Table 1, Figure 1 Type A *PN and DN in this standard represent pressure and nominal diameter respectively. Approved by the Ministry of Chemical Industry of the People's Republic of China on August 19, 1991. Standard Technology Network All kinds of standards industry information free download 1992-01-01 implementation Note: S in the figure and table refers to the front wall thickness of the glass. HG/T2138-91 32 Cast iron concentric glass reducer (type B) connected by slip-on flange shall comply with the provisions of Figure 2 and Table 2. Far standard network, b product, ccm customer standard industry qualification bidding ticket PN Reference weight, kg PN/MPa HG/T2138-91 Standard fee network , cem various standard industry information free of charge category d Reference weight, kgbZxz.net PN/MPa Note: S in the figure and table refers to the thickness of the front wall of the glass HG/T2138-91 3.3 Cast iron concentric glass reducer (type C) connected by flange shall comply with the provisions of Figure 3 and Table 3. 5 Various types of standard industry data are required below Reference weight, kg PN-0.6MPa PN/MPa HG/T2138—91 Note: S in the figure and table refers to the front wall thickness of the pond glass, D, 3.4 Marking example Type A pond glass concentric reducer, PN is 0.6MPaDN, is 80mm, DN is 50mm, marking: concentric reducer PN0.6DN80/50-AHG/T2138—914 Technical requirements 4,1 Material selection, manufacturing, testing and acceptance shall be carried out in accordance with ZBG94004 and this standard. 4.2 Manufacturing tolerance and allowable deviation Reference weight 4.2.1 The materials of Type B and Type C reducers shall comply with the relevant provisions of GB9439: 4.2.2 The allowable deviation of the center circle diameter of the bolt hole on the flange of Type C reducer and the chord length of two adjacent bolt holes is ±0.6mm. The allowable deviation of the chord length of any two bolt holes is +1mm. Standard investment network.breo5o:com All kinds of standard industry information are free to download HG/T2138-91 4.2.3 The tolerance grade of the un-indicated tolerance size of the machined surface shall be IT14 as specified in GB1804, and the tolerance grade of the un-indicated tolerance size of the non-machined surface shall be IT16. 4.2.4 The allowable deviation of the length L of the reducer shall be as specified in Table 4. Table 4 65~100 125~200 4.3 The slip-on flanges for Type A and Type B reducers shall be selected in accordance with HG/T2105. 250 4.4 Bolts for flange connection: When PN is greater than 0.6MPa and less than or equal to 1.0MPa, follow the provisions of GB5782; when PN is less than or equal to 0.6MPa, follow the provisions of GB5780; nuts shall follow the provisions of GB6170; gaskets shall be selected according to relevant standards; 4.5 Water pressure test pressure and maximum working pressure at different temperatures shall be selected according to Table 5 Table 5 Packaging, transportation and storage Test pressure 5.1 The product shall be accompanied by a packing list, product certificate and product instruction manual; 5.2 No collision shall be allowed during moving and transportation. 5.3 The exposed glass surface shall be sealed with soft gaskets and blind plates; 5.4 The product shall be stored indoors; open storage or stacking is not allowed; Additional instructions: This standard is proposed by China National Chemical Equipment Corporation. This standard is under the jurisdiction of the National Sugar Glass Equipment Standardization Technical Committee. This standard was drafted by the Shanghai Pharmaceutical Design Institute of the State Drug Administration. The main drafters of this standard are Li Yijun, Hua Qiuyuan and Bao Aiyuan. MPa Maximum working pressure P at the following temperature 200℃ From the date of implementation of this standard, the original standard HG5-259-79 "Tang Glass Concentric Reducer" issued by the Ministry of Chemical Industry of the People's Republic of China will be invalidated. Standard Search Network sbsos:som 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.