(1) Remove rust, dirt, and grease from the pipe joints.
(2) When using steam welding or mechanical cutting, the cross-section should be straight to ensure the concentricity of the steel pipe after welding. Burrs or attachments should be removed before welding.
(3) When opening a tee hole on the steel pipe, the pipe should be trimmed, and the residue inside the pipe should be cleaned. The height of the saddle-shaped opening should not be less than 1/2 of the pipe diameter.
(4) In order to ensure that the pipe wall can be fully welded during welding, the pipe end should be beveled. The bevel form can be selected according to the thickness of the pipe wall.
(5) For steel pipes with a wall thickness of less than 3.5mm, the bevel is not required. The gap between the ends is 1~2. For steel pipes with a wall thickness of more than 3.5mm, the bevel must be made. The bevel angle is generally 30°~35°, the blunt edge is 1~2, and the gap between the ends is 1~3.
(6) The groove can be formed by gas cutting (manual groove) or groove machine processing. After processing, the groove should be cleaned of slag and iron oxide and trimmed with a steel file until the metallic luster is exposed.
(7) When welding steel pipes of different wall thicknesses, the difference in wall thickness of the two steel pipes shall not exceed 10% of the smaller wall thickness, and shall not exceed 3mm at most (referring to the difference in wall thickness of the two steel pipes). Otherwise, the thicker steel pipe should be processed.
(8) When welding, the distance between the seams of two adjacent steel pipes shall not be less than 200mm, and the minimum distance shall not be less than the nominal diameter of the pipe.
Post time: Sep-04-2025