Detail of GB/T 2694-2018

Introduction of GB/T 2694-2018

Specification of manufacturing for transmission line tower 1 Scope This standard specifies the materials, technical requirements, test, packaging, marking, transportation and storage during the manufacturing process of transmission line tower (hereinafter collectively referred to "tower"). This standard is applicable to the manufacturing of steel angle tower for transmission line, and may be referred to for the manufacturing of power microwave tower, power communication tower and similar steel structures. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition (including any amendments) applies. GB/T 41 Hexagon nuts, style 1 - Product grade C GB/T 95 Plain washers - Product grade C GB/T 229 Metallic materials - Charpy pendulum impact test method GB/T 470 Zinc ingots GB/T 699 Quality carbon structural steels GB/T 700 Carbon structural steel GB/T 702 Hot-rolled steel bars - Dimensions, shape, weight and tolerances GB/T 706 Hot rolled section steel GB/T 709 Dimension, shape, weight and tolerance for hot-rolled steel strip, plate and sheet GB/T 805 Tight nuts GB/T 985.1 Recommended joint preparation for gas welding, manual metal arc welding, gas-shield arc welding and beam welding GB/T 1591 High strength low alloy structural steels GB/T 2828.1 Sampling procedures for inspection by attributes - Part 1: Sampling schemes indexed by acceptance quality limit (AQL) for lot-by-lot inspection GB/T 2829 Sampling procedures and tables for periodic inspection by attributes (apply to inspection of process stability) GB/T 3098.1 Mechanical properties of fasteners - Bolts, screws and studs GB/T 3098.2 Mechanical properties of fasteners - Nuts GB/T 3274 Hot-rolled plates, sheets and strips of carbon structural steels and high strength low alloy structural steels GB/T 3323 Radiographic examination of fusion welded joints in metallic materials GB/T 3524 Hot-rolled carbon and low alloy structural steel strips GB/T 5117 Covered electrodes for manual metal arc welding of non-alloy and fine grain steels GB/T 5118 Covered electrodes for manual metal arc welding of creep-resisting steels GB/T 5293 Solid wire electrodes, tubular cored electrodes and electrode/flux combinations for submerged arc welding of non alloy and fine grain steels GB/T 5313 Steel plate with through-thickness properties GB/T 5780 Hexagon head bolts - Product grade C GB/T 6052 Industrial liquid carbon dioxide GB/T 6170 Hexagon nuts, style 1 GB/T 8110 Welding electrodes and rods for gas shielding arc welding of carbon and low alloy steel GB/T 9448 Safety in welding and cutting GB/T 10045 Carbon steel flux cored electrodes for arc welding GB/T 11345 Non-destructive testing of welds - Ultrasonic testing - Techniques, testing levels, and assessment GB/T 12470 Solid wire electrodes, tubular cored electrodes and electrode/flux combinations for submerged arc welding of creep-resisting steels GB/T 13912 Metallic coatings - Hot dip galvanized coatings on fabricated iron and steel articles - Specifications and test methods GB/T 17493 Low alloy steel flux cored electrodes for arc welding GB/T 29711 Non-destructive testing of welds - Ultrasonic testing - Characterization of indications in welds GB/T 29712 Non-destructive testing of welds - Ultrasonic testing - Acceptance levels GB 50661 Code for welding of steel structures JB/T 3223 Welding consumables quality management procedures JG/T 203 Method for ultrasonic testing and classification for steel structures HG/T 3728 Mixed gas for welding Argon - Carbon dioxide 3 Terms, definitions and symbols 3.1 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1.1 part the smallest unit of a tower component or element, e.g., steel angle, steel plate, etc. 3.1.2 component unit consisting of several parts, e.g., weldment 3.1.3 element the basic unit of the tower composed of the fastened connection of parts and components 3.1.4 assembling the process of connecting parts together to make them components according to specified precision and technical requirements 3.1.5 test assembling assembling to test whether the elements or towers meet the design and installation quality requirements 3.1.6 hot-dip galvanizing the process and method for formation of a coating of zinc and/or zinc iron alloys on steel workpieces having been subjected to pretreatment such as rust removal by dipping them in a zinc melt 3.1.7 shearing section perpendicularity the inclination degree of steel plate or angle shearing section 3.1.8 angle sheared edge perpendicularity the inclination degree of the steel angle shearing edge to ridge line 3.1.9 rolled angle directrix the vertical distance between the center of the upper bolt hole and the back of the steel angle, which is usually classified into single-row directrix and double-row directrix 3.1.10 arc shoveling the process that the inner arc of the steel angle at the four corners is planed to a right angle to ensure the tight connection of steel angle 3.1.11 heel chipping the process that the back ridge edges and corners of the in-corner steel angle is shoveled into a smooth arc shape to ensure the tight connection of steel angles 3.2 Symbols For the purposes of this document, the following symbols apply. a——spacing, clearance, directrix B——weld width b——width, root face C——weld reinforcement d——hole diameter e——eccentric distance, displacement f——deflection, deformation, curvature, straightness, flatness, pre-arching g——bevel width h——height, vertical spacing hf——weld leg size L——contour size, length P——inclination, perpendicularity R——radius S——hole spacing, row spacing, end spacing, edge spacing t——thickness of plate or wall Z0——center of gravity α——angle δ——misalignment 4 General principle 4.1 The tower manufacturing and test shall meet the design requirements. When it is necessary to modify the design, the consent of the design organization shall be obtained and the design change document shall be signed. 4.2 Those unspecified in this standard shall comply with those specified in the current relevant standards of China. 4.3 When new technologies, new processes and new materials are adopted, they shall be tested, verified and evaluated as acceptable. 4.4 The tower production process shall meet the requirements for environment, safety and occupational health.

Contents of GB/T 2694-2018

Foreword i 1 Scope 2 Normative references 3 Terms, definitions and symbols 3.1 Terms and definitions 3.2 Symbols 4 General principle 5 Materials 5.1 Steel 5.2 Welding materials 5.3 Fasteners 5.4 Zinc ingots 6 Technical requirements 6.1 Shearing 6.2 Marking 6.3 Forming (bending, flattening, angle opening and closing) 6.4 Holing 6.5 Arc shoveling, heel chipping and beveling 6.6 Welding 6.7 Weldment assembling 6.8 Correction 6.9 Hot-dip galvanizing 6.10 Test assembling 7 Inspection 7.1 Quality certificate 7.2 Inspection items 7.3 Inspection requirements and methods 7.4 Sampling plan and judgment rules 8 Packaging, marking, transportation and storage 8.1 Packaging 8.2 Marking 8.3 Transportation and storage 9 Requirements for data transfer Annex A (Normative) Hot-dip galvanized coating uniformity test - Copper sulfate test method Annex B (Normative) Hot-dip galvanized coating adhesion test - Drop-weight test method Annex C (Normative) Test for thickness of hot-dip galvanized coatings - Thickness gauge test method for metal-plated coatings Annex D (Normative) Hot-dip galvanized coating mass test - Dissolve-to-weigh test method