GB/T 2694-2018Specification of manufacturing for transmission line tower (English PDF)

3.1 Terms and definitions

The following terms and definitions apply to this document.

3.2 Symbols

The following symbols apply to this document.

5.1 Steel

5.1.1 The specifications and grades of steel used in the manufacture of the tower shall be selected according to the design requirements;

5.1.2 Steel materials shall have traceability marks. If the original traceability marks are split during the manufacturing process, the marks shall be transplanted before the materials are split.

5.2 Welding materials

5.2.1 The quality of welding materials such as welding rods, welding wires, fluxes shall comply with the provisions of GB/T 5117, GB/T 5118, GB/T 5293, GB/T 8110, GB/T 10045, GB/T 12470, GB/T 17493.

5.2.2 The coating on the surface of the welding rod shall not fall off or be damp. The surface of the welding wire shall be smooth and flat; there shall be no burrs, scratches, rust, oxide scale or other impurities that have adverse effects on welding performance and welding equipment operation performance.

5.2.3 The welding gas shall meet the requirements of GB/T 6052 and HG/T 3728.

5.2.4 Before the first use of each welding material, the mechanical properties test of the deposited metal shall be carried out.

5.2.5 The management of welding materials shall comply with the provisions of JB/T 3223.

5.4 Zinc ingots

The quality requirements, test methods, inspection rules and markings, packaging, transportation and storage of zinc ingots shall comply with the provisions of GB/T 470.

6.1 Cutting

6.1.1 After cutting, there shall be no cracks or edge defects greater than 1.0 mm on the fracture. The flatness of the cut surface shall not be greater than 0.05t (t is the thickness) and shall not be greater than 2.0 mm. The depth of the cut mark shall not be greater than 0.3 mm. The allowable deviation of the local notch depth is 1.0 mm.

6.2 Marking

6.2.2 The steel stamps of the identification shall be arranged neatly; the font shall not have defects; the font height is 8 mm ~ 18 mm.

6.2.3 The steel stamp shall not be pressed on the hole making, bending, milling, welding parts.

6.3 Forming (bending, flattening, opening and closing angles)

6.4 Hole making

6.4.1 The punching surface shall not have obvious concave defects; burrs larger than 0.3 mm shall be removed. After hole making, there shall be no missing edges or collapsed angles larger than 0.5 mm at the boundary intersection between the hole wall and the part surface. The allowable deviation of hole making shall comply with the provisions of Table 4.

6.6 Welding

6.6.1 Welding procedure qualification

For the steel, welding materials, welding methods, structural forms, preheating, post-treatment, etc., which are used for the first time, welding procedure qualification shall be carried out in accordance with GB 50661 before welding work; welding process specifications and welding operation instructions shall be prepared.

6.6.2 Welder qualification

6.6.4 Welding groove

6.6.4.1 The form and size of the welding groove shall comply with the relevant provisions of GB/T 985.1 and GB/T 985.2. The form and size of the groove with special requirements for the drawings shall be determined, based on the drawings and combined with the welding procedure qualification.

6.6.4.2 The welding groove shall be processed by mechanical methods first. When flame cutting is used, the weld groove shall be flat, free of burrs, cracks, gas cutting nodules, interlayers or other defects.

6.6.5 Welding rework

7.1 Certificate of conformity

Products shall be inspected and accepted before leaving the factory and a product certificate of conformity shall be issued.

7.3 Inspection requirements and methods

7.4 Sampling plan and judgment principle

7.4.1 Sampling principle

7.4.2 Inspection batch

The inspection batch can be composed of several production batches or part of the production batch. The exit-factory inspection batch is determined according to the actual situation. The inspection batch accepted by the buyer shall be based on the contractual agreement between the supplier and the buyer.

7.4.6 Judgment principle

7.4.6.1 Judgment principle for parts

When the inspected parts have one of the following conditions, they shall be judged as unqualified. […]

7.4.6.2 Comprehensive judgment principle

If one of the items in Class A is unqualified, the product shall be judged as unqualified; if one of the items in Class B is not less than the rejection number (Re), the product shall be judged as unqualified.

8.1 Packaging

8.1.1 Angle steel packaging

8.1.1.1 The packaging length, number of bundles and weight of angle steel shall be convenient for packaging, transportation, marking.

8.1.2 Connection plate packaging

The connection plate packaging should be fastened by long bolts and a lifting point shall be set.

8.2 Marking

In addition to meeting the contract requirements, the marking shall also be identified in a conspicuous position on the bundle, indicating the project name, tower type, nominal height, tower number, bundle number, manufacturer name; the marking content shall also meet the requirements of the transportation department.

8.3 Transportation and storage

During loading, unloading, transportation and storage, the packaging must not be damaged to cause deformation of the product or damage to the galvanized layer.