Seamless steel pipe installation and matters needing attention

smls pipe installation and matters needing attention:

1) Construction preparation

a. Operating conditions: the pipeline ditch surface is completed; the pipeline well is bricked.
b. Material requirements: complete pipelines of various specifications and models.
c. Main machines and tools: cutting machine, electric welding machine, polishing machine, electric hammer, etc.

2) Quality requirements

The allowable deviation per meter for the vertical installation of the riser is 3mm, and the allowable deviation is not more than 8mm for more than 5m. The allowable deviation per meter for horizontally installed pipes is 1mm.

3) Pipeline installation

1. Production and installation of pipe support:
According to the design of the drawings, the pipeline is positioned, and the pipeline supports are prefabricated according to the site conditions. Hang the wire down from the 25th floor, and then fix the bracket.

2. Pipeline installation:
Cut the material according to the design and on-site, and then use a grinder to bevel the groove, and the bevel 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 misaligned during assembly. The electric welding position is generally 4 spot welding. After checking and straightening, use the free conversion method to weld as much as possible.

4) Quality requirements

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

5) Safety precautions

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