GB/T 25178-2020 English PDFUS$429.00 · In stock
Delivery: <= 4 days. True-PDF full-copy in English will be manually translated and delivered via email. GB/T 25178-2020: Reduced-pressure type backflow preventer Status: Valid GB/T 25178: Historical versions
Basic dataStandard ID: GB/T 25178-2020 (GB/T25178-2020)Description (Translated English): Reduced-pressure type backflow preventer Sector / Industry: National Standard (Recommended) Classification of Chinese Standard: P41 Classification of International Standard: 91.140.60 Word Count Estimation: 23,214 Date of Issue: 2020-12-14 Date of Implementation: 2020-12-14 Older Standard (superseded by this standard): GB/T 25178-2010 Quoted Standard: GB/T 196; GB/T 1047; GB/T 1048; GB/T 1732; GB/T 3098.1; GB 5135.11; GB/T 5210; GB/T 6739; GB/T 7306.2; GB/T 9124.1; GB/T 12220; GB/T 12225; GB/T 12227; GB/T 12230; GB/T 13452.2; GB/T 13927; GB/T 17219; GB/T 17241.6; GB/T 17241.7; GB/T 20878; GB/T 21873 Regulation (derived from): National Standard Announcement No. 28 of 2020 Issuing agency(ies): State Administration for Market Regulation, China National Standardization Administration Summary: This standard specifies the terms and definitions, classification, model marking, material and structure, requirements, test methods, inspection rules, marking, packaging, storage and transportation of pressure-reducing backflow preventers. This standard is applicable to decompression type backflow preventers (hereinafter referred to as "backflow preventers") that transport drinking water with nominal pressure not greater than PN16, nominal size DN15��DN400, and medium temperature not higher than 65��. GB/T 25178-2020: Reduced-pressure type backflow preventer---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order.(Pressure reducing type backflow preventer) ICS 91:140:60 P41 National Standards of People's Republic of China Replace GB/T 25178-2010 Pressure reducing type backflow preventer 2020-12-14 release 2020-12-14 implementation State Administration for Market Regulation Issued by the National Standardization Management Committee Table of contentsForeword Ⅰ 1 Scope 1 2 Normative references 1 3 Terms and definitions 2 4 Classification and model marking 2 5 Materials and structure 3 6 Requirements 4 7 Test method 6 8 Inspection rules 10 9 Marking, packaging, storage and transportation 11 Appendix A (informative appendix) Overall structure of decompression type backflow preventer 13 Appendix B (Normative Appendix) Testing and Testing Equipment Figure 16ForewordThis standard was drafted in accordance with the rules given in GB/T 1:1-2009: This standard replaces GB/T 25178-2010 "Decompression Backflow Preventer", compared with GB/T 25178-2010, except for editorial changes The main technical changes are as follows: ---Modified terms and definitions such as "pressure-reducing backflow preventer", "zero flow" (see 3:1~3:5, 3:1~3:5 in:2010 edition); --- Deleted the terms and definitions of "independently acting check valve" and "PN (nominal pressure)" (see 3:6 and 3:7 of the:2010 edition); ---Added the terms and definitions of "initial release pressure difference" (see 3:6); ---The content of Chapter 5 of the:2010 edition was changed to Chapter 4, and the model designation was revised (see 4:2, 5:1 of the:2010 edition); ---The contents of Chapter 4 and Chapter 6 of the:2010 edition are merged into Chapter 5, and the requirements for detecting ball valves are modified (see 5:2:3, 6:2,:2010 edition 4:1:2); ---Modified the online maintenance requirements (see 5:2:4, 4:1:3 of the:2010 edition); ---The structural design requirements of the drain valve have been moved from 7:10:1 in the:2010 edition to 5:2:5 (see 5:2:5 and 7:10:1 in the:2010 edition); ---The requirements for the shut-off valve in Appendix A of the:2010 edition have been moved to 5:2:6, and the sealing form requirements of the shut-off valve have been added (see 5:2:6, Appendix AA:2 of the:2010 edition); ---Modified the connection form requirements in the structural form (see 6:2:4, 4:2 in the:2010 edition); ---The appearance and painting requirements and test methods have been revised (see 6:1, 7:1,:2010 edition of 7:4, 8:1:2); ---Modified the strength requirements (see 6:3, 7:7 in the:2010 edition); ---Modified the performance requirements of the check valve (see 6:4, 7:8 in the:2010 edition); ---Modified the hydraulic characteristics requirements (see 6:5, 7:9 in the:2010 edition); ---Revised the pressure loss requirements (see 6:6, 7:9:3 of the:2010 edition); ---Modified the performance requirements of the drain valve (see 6:7, 7:10 in the:2010 edition); ---Added the sensitivity performance requirements and test methods of the drain valve (see 6:7:2, 7:7:2); ---Added cyclic test, hygiene requirements and test methods (see 6:9, 6:10, 7:9, 7:10); ---Modified the water inlet pressure during the hydraulic characteristic test, pressure loss test, and discharge valve opening and closing performance test: The test device diagram was moved to the attached Record B (see 7:5, 7:6, 7:7:1, Appendix B, 8:3~8:9 of the:2010 edition); ---Modified the factory inspection items (see 8:2, 9:1 of the:2010 edition); ---Modified the type test and sampling rules (see 8:3, 9:2, 9:3 of the:2010 edition); ---Modified the product mark (see 9:2, 10:2 of the:2010 edition): This standard was proposed by the Ministry of Housing and Urban-Rural Development of the People's Republic of China: This standard is under the jurisdiction of the National Urban Water Supply and Drainage Standardization Technical Committee (SAC/TC434): Drafting organizations of this standard: China Construction Metal Structure Association, Guangdong Yongquan Valve Technology Co:, Ltd:, Shanghai Guanlong Valve Machinery Co:, Ltd: Co:, Ltd:, China Energy Construction Group Guangdong Electric Power Design and Research Institute Co:, Ltd:, Shandong Jianhua Valve Manufacturing Co:, Ltd:, Anhui Tongduliu Body Technology Co:, Ltd:, Bona Siwei Valve Co:, Ltd:, Shandong Ryder Pipe Valve Co:, Ltd:, Anhui Red Star Valve Co:, Ltd:, Hangzhou Zhou Chunjiang Valve Co:, Ltd:, Tianjin Tanggu First Valve Co:, Ltd:, Shanghai Airlines Technology Group Co:, Ltd:, Wuhan Dayu Valve Co:, Ltd: Company, Jinan Mike Valve Technology Co:, Ltd:, China Municipal Engineering Central South Design and Research Institute Co:, Ltd:, Tianjin Guowei Water Supply and Drainage Equipment Manufacturing Co:, Ltd:, Ningbo Huacheng Valve Co:, Ltd:, Zhuzhou South Valve Co:, Ltd:, Shanghai Shanglong Water Supply Equipment Co:, Ltd:, Jiangsu Zhuxu Valve Industry Co:, Ltd:, Ningbo Jiekelong Precision Co:, Ltd:, Roland Automatic Valve Industry (Shanghai) Co:, Ltd:, China Valve Holdings (Group) Co:, Ltd: Company, Shanghai Yucheng Fluid Control Co:, Ltd:, Pulian Power Fluid Control (Shanghai) Co:, Ltd:, Yuanda Valve Group Co:, Ltd:, Shanghai Hugong Valve Factory (Group) Co:, Ltd:, Northwest Survey, Design and Research Institute Co:, Ltd: of China Power Construction Corporation: The main drafters of this standard: Qin Yongxin, Liu Jie, Ge Xin, Chen Jianming, Huo Dawen, Li Zhenghong, Liu Fengnian, Bruce Lee, Wang Huamei, Yan Jie, Liao Zhifang, Zhang Hairuo, Han Anwei, Lu Yuanhang, Hong Rongkun, Chen Siliang, Li Xihong, Wang Shixin, Bi Aijun, Liu Yong, Wang Chaoyang, Xie Aihua, Ji Nengping, Xiao Peng, Yan Rongjie, Chen Lili, Shen Weiguang, Zheng Chengchao, Li Lianliang, Shao Jiannong, Yang Xiongjun, Ma Long: The previous versions of the standard replaced by this standard are as follows: ---GB/T 25178-2010: Pressure reducing type backflow preventer1 ScopeThis standard specifies the terms and definitions, classification, model marking, materials and structure, requirements, test methods, and inspections of pressure-reducing backflow preventers Rules, signs, packaging, storage and transportation: This standard is suitable for conveying the nominal pressure not greater than PN16, the nominal size DN15~DN400, and the medium temperature not higher than 65℃: Decompression type backflow preventer for water use (hereinafter referred to as "backflow preventer"):2 Normative referencesThe following documents are indispensable for the application of this document: For dated reference documents, only the dated version applies to this article Pieces: For undated references, the latest version (including all amendments) applies to this document: GB/T 196 basic size of ordinary thread GB/T 1047 Definition and Selection of Nominal Dimensions of Piping Components GB/T 1048 Definition and selection of nominal pressure of pipeline components GB/T 1732 Test Method for Impact Resistance of Paint Film GB/T 3098:1 Mechanical properties of fasteners bolts, screws and studs GB 5135:11 Automatic sprinkler system Part 11: Groove type pipe joint GB/T 5210 Paint and varnish pull open adhesion test GB/T 6739 Paint and varnish pencil method for determination of paint film hardness GB/T 7306:2 55° Sealed Pipe Thread Part 2: Conical Internal Thread and Conical External Thread GB/T 9124:1 Steel pipe flanges Part 1: PN series GB/T 12220 Industrial valve mark GB/T 12225 General Valve Copper Alloy Casting Technical Conditions GB/T 12227 Technical conditions for general valve ductile iron castings GB/T 12230 General valve stainless steel casting technical conditions GB/T 13452:2 Determination of film thickness of paints and varnishes GB/T 13927 Industrial valve pressure test GB/T 17219 Safety evaluation standard for drinking water distribution equipment and protective materials GB/T 17241:6 Integral cast iron flange GB/T 17241:7 Technical conditions for cast iron pipe flanges GB/T 20878 Stainless steel and heat-resistant steel grades and chemical composition GB/T 21873 Rubber Sealing Material Specification for Interface Sealing Rings for Water Supply, Drainage and Sewage Pipes GB/T 24588 Stainless steel spring wire GB/T 26640 Specification for minimum wall thickness of valve housing CJ/T 216 Soft Seal Gate Valve for Water Supply and Drainage JB/T 7927 Appearance quality requirements of valve steel castings JB/T 7928 Industrial valve supply requirements ......Tips & Frequently Asked Questions:Question 1: How long will the true-PDF of GB/T 25178-2020_English be delivered?Answer: Upon your order, we will start to translate GB/T 25178-2020_English as soon as possible, and keep you informed of the progress. 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Otherwise, follow the normal steps: Add to Cart -- Checkout -- Select your currency to pay.Question 5: Should I purchase the latest version GB/T 25178-2020?Answer: Yes. Unless special scenarios such as technical constraints or academic study, you should always prioritize to purchase the latest version GB/T 25178-2020 even if the enforcement date is in future. Complying with the latest version means that, by default, it also complies with all the earlier versions, technically. |
