Seamless steel pipe installation and precautions

Seamless steel pipe installation and precautions:

A. Construction preparation

(1) Operating conditions
The ground of the pipeline trench is completed; the bricklaying of the pipeline well is completed.

(2) Material requirements
Various specifications and models of pipes are complete.

(3) Main equipment
Cutting machine, electric welding machine, polishing machine, electric hammer, etc.

B. Quality requirements

The allowable deviation of the vertically installed riser is 3mm per meter, and the allowable deviation above 5m is not more than 8mm. Horizontally installed pipes are allowed a deviation of 1mm per meter.

C. Pipeline installation

1. Pipe support production and installation:
Design according to drawings, carry out pipeline positioning, and prefabricate pipeline supports according to site conditions. Hang the wire down from the 25th floor, and then fasten the bracket.

2. Pipeline installation:
The material is cut according to the design and on-site, and then the groove is made with a polishing machine, and the groove angle is 60°~65°. Fix the processed pipe on the bracket, the gap between the two pipes is 1.5mm~2.5mm, and then weld.

There should be no bends at the welding joints, and the joints should not be wrong when grouping. The welding positioning is generally 4 spot welding. After inspection and straightening, use the free conversion method for welding as much as possible.

D. Quality requirements

1. The branch pipe shall not be welded at the weld, and there shall be no weld at the bend;
2. The welding joint is straight, the welding seam is full, and the surface of the welding joint has no defects such as burn-through, cracks and obvious nodules, slag addition and pores.
3. The welding wave is uniform and the misalignment deviation of the pipe counterpart should not exceed 20% of the pipe wall thickness, and should not exceed 2mm.

E. Safety precautions

1. The shell of the electric welding machine must be well grounded, and the welding tongs and the welding handle wire must be well insulated;
2. Wear protective equipment when using the welding machine.