Standard No.:	GB/T 9948-2025
English Name:	Seamless steel tubes and pipes for petrochemical and chemical facilities
Chinese Name:	石化和化工装置用无缝钢管
Professional Classification:	GB    National Standard
Source Content Issued by:	SAMR; SAC
Issued on:	2025-06-30
Implemented on:	2026-1-1
Status:	to be valid
Superseding:	GB/T 9948-2013 Seamless steel tubes for petroleum cracking GB/T 6479-2013 GB/T 24592-2009 High pressure alloy steel tubes for polyethylene service GB/T 33167-2016 Seamless stainless steel tubes and pipes for industrial furnace of petroleum and chemical hydrogenation unit
Target Language:	English
File Format:	PDF
Word Count:	19000 words
Translation Price(USD):	570.0
Delivery:	via email in 1~3 business day

ICS 77.140.75 CCS H 48 National Standard of the People’s Republic of China GB/T 9948-2025 Replaces GB/T 9948-2013, GB/T 6479-2013, GB/T 24592-2009, GB/T 33167-2016 Seamless steel tubes and pipes for petrochemical and chemical facilities (English Translation) Issue date: 2025-06-30 Implementation date: 2026-01-01 Issued by State Administration for Market Regulation of the People's Republic of China the Standardization Administration of the People's Republic of China Seamless steel tubes and pipes for petrochemical and chemical facilities 1 Scope This document specifies the classification, code, order contents, manufacturing processes, technical requirements, samples, test methods, inspection rules, packaging, marking and quality certificate of seamless steel tubes and pipes for petrochemical and chemical facilities. This document is applicable to seamless steel tubes and pipes for petroleum cracking, high-pressure fertilizer equipment, high-pressure alloy steel pipes for polyethylene and stainless steel seamless steel pipes for industrial furnaces of petrochemical hydrogenation units (hereinafter referred to as "steel pipes"). 2 Normative references The following documents contain provisions which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition (including any amendments) applies. GB/T 222 Permissible tolerances for chemical composition of steel products GB/T 223. 5 Steel and iron - Determination of acid-soluble silicon and total silicon content - Reduced molybdosilicate spectrophotometric method GB/T 223. 9 Iron, steel and alloy - Determination of aluminum content - Chrome azurol S photometric method GB/T 223.11 Iron, steel and alloy - Determination of chromium content - Visual titration or potentiometric titration method GB/T 223.12 Methods for chemical analysis of iron, steel and alloy The sodium carbonate separation-diphenyl carbazide photometric method for the determination of chromium content GB/T 223.14 Methods for chemical analysis of iron, steel and alloy - The N-benzoy-N-phenylhydroxylamine extraction photometric method for the determination of vanadium content GB/T 223.18 Methods for chemical analysis of iron, steel and alloy - The sodium thiosulfate separation iodimetric method for the determination of cupper content GB/T 223. 19 Methods for chemical analysis of iron, steel and alloy - The neocuproine-chloroform extraction photometric method for the determination of copper content GB/T 223. 23 Iron, steel and alloy - Determination of nickel content - The dimethylglyoxime spectrophotometric method GB/T 223. 25 Methods for chemical analysis of iron, steel and alloy - The dimethylglyoxime gravimetric method for the determination of nickel content GB/T 223.26 Iron steel and alloy - Determination of molybdenum content - The thiocyanate spectrophotometric method GB/T 223.28 Methods for chemical analysis of iron steel and alloy - The α-Benzoinoxime gravimetric method for the determination of molybdenum content GB/T 223.29 Iron, steel and alloy - Determination of lead content - Carrier precipitation-xylenol orange spectrophotometric method GB/T 223.30 Methods for chemical analysis of iron, steel and alloy The arsenazo Ⅲ spectrophotometric method for the determination of zirconium content after separation by p-bromomandelic acid GB/T 223.31 Iron, steel and alloy - Determination of arsenic content - Distillation-molybdenum blue spectrophotometric method GB/T 223.36 Methods for chemical analysis of iron, steel and alloy - The neutral titration method for the determination of nitrogen content after distillation separation GB/T 223.37 Iron, steel and alloy - Determination of nitrogen content - Indophenol blue spectrophotometric method after distillation separation GB/T 223.38 Methods for chemical analysis of iron, steel and alloy - The anion-exchange separation-gravimetric method for the determination of niobium content GB/T 223.40 Iron, steel and alloy - Determination of niobium content by the sulphochlorophenol S spectrophotometric method GB/T 223.43 Iron steel and alloy - Determination of tungsten content - Gravimetric method and spectrophotometric method GB/T 223.47 Methods for chemical analysis of iron, steel and alloy - The carrier precipitation-molybdenum blue potometric method for the determination of antimony content GB/T 223.50 Methods for chemical analysis of iron, steel and alloy - The phenylfluorone-CTMAB direct photometric method for the determination of tin content GB/T 223.59 Iron steel and alloy - Determination of phosphorus content - Bismuth phosphomolybdate blue spectrophotometric method and antimony phosphomolybdate blue spectrophotometric method GB/T 223.63 Iron, steel and alloy - Determination of manganese content - Sodium (potassium) periodate spectrophotometric method GB/T 223.78 Methods for chemical analysis of iron, steel and alloy - Curcumin spectrophotometric method for the determination of boron content GB/T 223.80 Iron steel and alloy - Determination of trace bismuth and arsenic contents - Hydride generation-atomic fluorescence spectrometric method GB/T 223.84 Steel and iron - Determination of titanium content - Diantipyrylmethane spectrophotometric method GB/T 223.85 Steel and iron - Determination of sulfur content - Infrared absorption method after combustion in an induction furnace GB/T 223.86 Steel and iron - Determination of total carbon content - Infrared absorption method after combustion in an induction furnace GB/T 226 Test method for macrostructure and defect of steel by etching GB/T 228.1 Metallic materials - Tensile testing - Part 1 : Method of test at room temperature GB/T 228.2 Metallic materials - Tensile testing - Part 2 : Method of test at elevated temperature GB/T 229 Metallic materials - Charpy pendulum impact test method GB/T 231.1 Metallic materials - Brinell hardness test - Part 1 : Test method GB/T 232 Metallic materials - Bend testing method GB/T 241 Metallic materials - Tube - Hydrostatic pressure test GB/T 242 Metallic materials - Tube - Drift expanding test GB/T 246 Metallic materials - Tube - Flattening test GB/T 1979 Standard diagrams for macrostructure and defect of structural steels GB/T 2102 Acceptance, packaging, marking and quality certification for steel tubular products GB/T 2975 Steel and steel products - Location and preparation of samples and test pieces for mechanical testing GB/T 4334-2020 Determination of estimating the average grain size of metal GB/T 4336 Carbon and low-alloy steel - Determination of multi-element contents - Spark discharge atomic emission spectrometric method (routine method) GB/T 5777-2019 Automated full peripheral ultrasonic testing of seamless and welded (except submerged arc-welded) steel tubes for the detection of longitudinal and/or transverse imperfections GB/T 6060.2 Roughness comparison specimens - Ground, turned, bored, milled, shaped and planed GB/T 6394 Determination of estimating the average grain size of metal GB/T 7735 Automated eddy current testing of seamless and welded (except submerged arc-welded) steel tubes for detection of imperfections GB/T 10561-2023 Determination of content of nonmetallic inclusions in steel - Micrographic method using standard diagrams GB/T 11170 Stainless steel - Determination of multi-element contents - Spark discharge atomic emission spectrometric method (Routine method) GB/T 12606 Automated full peripheral flux leakage testing of seamless and welded (except submerged arc-welded) ferromagnetic steel tubes for the detection of longitudinal and/or transverse imperfections GB/T 17395 Dimensions, shapes, masses and tolerances of steel tubes GB/T 20066 Steel and iron - Sampling and preparation of samples for the determination of chemical composition GB/T 20123 Steel and iron - Determination of total carbon and sulfur content - Infrared absorption method after combustion in an induction furnace (routine method) GB/T 20124 Steel and iron - Determination of nitrogen content - Thermal conductimetric method after fusion in a current of inert gas (routine method) GB/T 20125 Low-alloy steel - Determination of multi-element contents - Inductively coupled plasma atomic emission spectrometric method GB/T 20972.2 Petroleum and natural gas industries -Materials for use in H2S-containing environments in oil and gas production - Part 2 : Cracking-resistant carbon and low alloy steels, and the use of cast irons GB/T 30062 Terminology of steel pipes and tubes GB/T 31925-2015 Ultrasonic test methods of heavy wall thickness seamless steel pipes and tubes GB/T 42673 Non-destructive testing of steel tubes - Magnetic particle inspection of seamless and welded ferromagnetic steel tubes for the detection of surface imperfections GB/T 42677 Non-destructive testing (NDT) methods of steel tubes - Liquid penetrant inspection of seamless and welded steel tubes for the detection of surface imperfections SH/T 3037 Calculation of heater-tube thickness in petroleum refineries YB/T 4149 Continuously cast round billet for seamless steel tube rolling YB/T 4395 Steel - Determination of molybdenum, niobium and tungsten contents - Inductively coupled plasma atomic emission spectrometric method YB/T 4396 Stainless steel - Determination of multi-element contents - Inductively coupled plasma atomic emission spectrometric method YB/T 5137 Hot rolled and wrought round blank for high-pressure seamless steel tube 3 Terms and definitions For the purpose of this document, the terms and definitions given in GB/T 30062 apply. 4 Classification and symbols 4.1 The seamless steel pipes hereof are classified into two types according to the manufacturing methods of product, and their categories and codes are as follows: a) hot-rolled (extruded, jacked, forged, expanded) steel pipes, coded W-H; b) cold-drawn (rolled) steel pipes, coded W-C. 4.2 For the purposes of this document, the following symbols apply. D: outside diameter (unless otherwise specified, including nominal outside diameter and/or calculated outside diameter, in mm) S: wall thickness (unless otherwise specified, including nominal and/or average wall thickness, in mm) Sc: average wall thickness (the average of the maximum and minimum wall thicknesses calculated as per the minimum wall thickness and its permissible deviation, in mm) Smin: minimum wall thickness L: length 5 Order contents The contract for purchasing steel pipes in accordance with this document shall cover the following information: a) product name; b) number of this standard; c) designation or uniform numerical code of steel; d) ordering quantity (total weight or total length); e) dimensions (external diameter × wall thickness, in: mm); f) delivery state; g) special requirements. 6 Manufacturing processes 6.1 Methods for smelting steel 6.1.1 High-quality carbon steel, low-alloy steel and alloy steel shall be treated by electric arc furnace plus external refining and vacuum refining, or by oxygen converter plus external refining and vacuum refining, or smelted by electroslag remelting process. 6.1.2 Stainless steel shall be treated by electric arc furnace plus external refining, or by oxygen converter plus external refining, or smelted by electroslag remelting process. 6.1.3 As agreed upon between the supplier and the purchaser and indicated in the contract, other smelting methods of higher requirements may be adopted. When the purchaser specifies a certain smelting method, it shall be indicated in the contract. 6.2 Methods for manufacturing pipe blank The tube blank may be manufactured by continuous casting, die casting or hot-rolling (forging). 6.3 Methods for manufacturing steel pipes 6.3.1 High-quality carbon steel, low-alloy steel and other alloy steel pipes except 35CrNi3MoV steel pipe for polyethylene shall be manufactured by seamless hot rolling (extrusion, jacking and expansion) or cold drawing (rolling). 6.3.2 Steel pipes shall be manufactured by hot rolling (extrusion) or cold drawing (rolling) seamless method. 6.3.3 35CrNi3MoV steel pipe for polyethylene can be manufactured by forging round billet or rolling round billet through mechanical processing, or by hot rolling (extrusion and jacking) seamless method.