1. Welded joints, welds with longitudinal and transverse intersections shall be welded to the welds after welds.

2. If the joint length exceeds 1 m, the symmetrical welding method or the step-by-step welding method shall be adopted.

3. When the butt joint and the fillet weld are present at the same time, the butt joint of the welded plate, the butt weld of the rear weld stand, and the corner weld of the weld stand and the plate shall be first.

4. Where symmetrical objects should be welded from the center to the head-to-tail direction and symmetrically left, right, and direction.

5. When the object, flat, vertical and fillet welding are present at the same time, the fillet weld should be welded first, then the fillet weld should be welded first; the short weld be welded first, and the long weld be welded later.

6. All lifting "horse", the welding feet should be the corner of the weld around the thickness of the "hanging horse", carefully check the quality of the weld after welding.

7. The quality of the weld of the component is not good. It should be corrected in the case of the component and should not be left in the overall installation and welding.

Quality requirements

1. Important structure Butt welds are inspected according to the technical requirements of various design specifications for a certain number of X-ray or ultrasonic seam internal inspections, and are rated according to the design specifications.

2. External weld inspection, so all structural welds are inspected, and the weld quality requirements are:

1 Straightness of weld seam, straightness of any part within ≤100mm ≤2mm.

2 The weld should be smooth and not abrupt to <90° transition angle.

3 The height difference of the weld is 25mm in length, and the height difference should be ≤1.5mm.

4 K-value tolerance of fillet weld is 0.9K0 ≤ K ≤ K0+1 when the thickness of the object is ≤ 4mm; 0.9K0 ≤ K ≤ K0+2 when the thickness of the object is > 4mm. (K0 is the design solder fillet size)

5 Weld undercut: when the thickness is ≤6mm d≤0.3mm, d<0.5mm;

When the plate thickness is >6mm d≤0.5mm (d is the undercut depth)

6 Welds are not allowed to be present below the surface of the workpiece and cracks and defects that have not yet been fused.

7 The depth of the intersection of the stacking of multiple weld surface surfaces shall be ≤1mm.

8 All welding defects are allowed to be repaired and smoothed after repair.

9 When the component material is a steel casting, it must be annealed at 550 °C after welding to eliminate stress.

3. The welded structure allows for firework correction.