GB/T 45344-2025 General technical requirements for fabricated and prefabricated gas piping used in buildings English, Anglais, Englisch, Inglés, えいご
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ICS91.140
CCS P 47
National Standards of the People's Republic of China
GB/T 45344-2025
General technical requirements for fabricated and prefabricated gas piping used in building
建筑用装配式预制燃气管道通用技术条件
(English Translation)
Issue date: 2025-02-28 Implementation date: 2026-09-01
Issued by the State Administration for Market Regulation
the Standardization Administration of the People's Republic of China
Contents
Foreword
1 Scope
2 Normative references
3 Terms and Definitions
4 Classification and model
5 Materials, construction, dimensions and connections
6 Requirements
7 Test methods
8 Factory inspection
9 Signs and installation instructions
10 Packaging, transportation and storage
Annex A (Informative) Schematic diagram of partial prefabricated piping
Bibliography
General technical requirements for fabricated and prefabricated gas piping used in building
1 Scope
This document specifies the classification and model, materials, structures, sizes and connections, requirements, test methods, factory inspection, marking, installation instructions, packaging, transportation and storage of prefabricated gas pipelines for buildings.
This document is applicable to town gas and the nominal pressure (PN) is not greater than 0.4 MP in buildings, prefabricated gas pipelines with nominal size not greater than DN80.
2 Normative references
The contents of the following documents constitute the essential provisions of this document through normative references in the text. Among them, for the referenced document with a date, only the version corresponding to that date is applicable to this document; the latest version of the undated referenced document (including all amendments) is applicable to this document.
GB/T 196 Basic dimensions of common threads
GB/T 222 Allowance of finished chemical composition of steel
GB/T 2828.1 Counting sampling inspection procedure - Part 1: Batch-by-batch inspection sampling plan retrieved by acceptance quality limit (AQL)
GB/T 3091 Welded steel pipe for low pressure fluid conveying
GB/T 3287 Malleable cast iron pipe connector
GB/T 5231 Processing grades and chemical compositions of copper and copper alloys
GB/T 6739 Determination of paint film hardness by pencil method for paints and varnishes
GB/T 7306.1 55 ° sealed pipe threads - Part 1: Cylindrical internal threads and conical external threads
GB/T 7306.2 55 ° sealed pipe threads - Part 2: Tapered female and tapered external threads
GB/T 7307 55 ° unsealed pipe thread
3 Terms and definitions
The following terms and definitions apply to this document.
3.1
fabricated and prefabricated gas piping used in building
gas pipeline has the main characteristics of standardized design, factory production, assembly construction and integrated integration. The prefabricated pipe sections and pipe fittings manufactured by industrial production are assembled at the construction site
4 Classification and model
4.1 Categories
4.1.1 According to the different materials selected, the prefabricated pipe sections are divided into:
a) carbon steel prefabricated pipe section, code CS;
b) stainless steel prefabricated pipe section, code SS.
4.1.2 According to connection mode, it is divided into:
a) welded connection, code W;
b) threaded connection, code T;
c) flange connection, code F.
4.2 Model
Principles for compiling models of prefabricated pipe sections
5 Materials, construction, dimensions and connections
5.1 Materials
5.1.1 The material selection of prefabricated pipes shall comply with Table 1 and the following provisions.
a) When the prefabricated material is carbon steel, the prefabricated pipe sections should be made of pipes that comply with the provisions of GB/T 3091, GB/T 8163 or equivalent performance or above, and the pipe fittings should be made of pipe fitting materials that comply with GB/T 3287, GB/T 13401, GB/T 5231 or equivalent performance or above.
b) When the prefabricated material is stainless steel, the prefabricated pipe sections should be made of stainless-steel materials that comply with the provisions of GB/T 14976, GB/T 12771 or equivalent performance or above, and the pipe fittings should be made of stainless-steel materials that comply with the provisions of GB/T 13401, GB/T 5231 or pipe fitting materials with equivalent performance or above.
5.1.2 The allowable deviation of chemical composition of finished prefabricated pipe section shall comply with the provisions of GB/T 222.
5.1.3 When prefabricated pipe sections and pipe fittings are subjected to external anti-corrosion treatment, the following requirements should be met.
a) When epoxy powder, graft copolymer powder and polyester powder are used for sequential spraying, they should comply with the provisions of GB/T 37594.
b) When using epoxy resin powder, polyester resin powder, epoxy resin paint, acrylic paint, acrylic polyurethane paint and other anti-corrosion coatings, they should comply with the provisions of GB/T 42541.
c) When hot-dip galvanized coating is used, the quality of the galvanized coating of prefabricated pipe sections should comply with the provisions of GB/T 3091 or GB/T 8163, and the quality of the galvanized coating of pipe fittings should comply with the provisions of GB/T 3287.
5.2 Structure
The prefabricated pipe structure shall be consistent with the design documents.
5.3 Dimensions
5.3.1 The nominal dimension, outer diameter, wall thickness and allowable tolerance of prefabricated pipe sections shall be consistent with the design documents and meet the following requirements.
a) When prefabricated from carbon steel materials, the nominal dimensions, outer diameter wall thickness and allowable tolerances of the prefabricated pipe sections should comply with the provisions of GB/T 3091 and GB/T 8163.
b) When prefabricated from stainless steel materials, the nominal dimensions, outer diameter, and wall thickness of the prefabricated pipe sections should comply with the provisions of Table 2, and the allowable tolerances should comply with the provisions of GB/T 14976 and GB/T 12771.
5.3.2 When the pipe is a threaded interface, the thread surface roughness Ra, not greater than 3.2μm, and the wall thickness of the pipe fittings should meet the following requirements.
a) When the surface is subjected to electroplating and other anti-corrosion treatments, the wall thickness of the pipe fittings should not be less than 2.0 mm.
b) When the raw material is lead brass, the wall thickness of the pipe fittings should not be less than 1.5 mm.
c) When the raw material is stainless steel, the wall thickness of the pipe fittings should not be less than 1.0 mm.
