1. Thick-walled steel pipe cutting: According to the actual required pipeline length, the pipe should be cut with a metal saw or a toothless saw. When water welding is used in the cutting process, the raw materials should be protected accordingly. When cutting, fire-resistant and heat-resistant materials should be used as baffles at the two ends of the fracture to catch the sparks and hot molten iron that fall during cutting to protect the raw materials. The original plastic layer.
2. Thick-walled steel pipe connection: After the plastic repair is completed, connect the pipe and pipe fittings and install rubber pads between the flanges during the connection process, and tighten the bolts to the sealed state.
3. Thick-walled steel pipe plastic coating treatment: After polishing, use oxygen and C2H2 to heat the pipe mouth outside the pipe until the internal plastic layer is melted, and then the skilled worker will evenly apply the prepared plastic powder to the pipe mouth, Should pay attention to correspondingly to be smeared in place, and the flange plate should be smeared above the water stop line. In this process, the heating temperature should be strictly controlled. If the temperature is too high, bubbles will be generated during the plastic coating process. If the temperature is too low, The plastic powder will not melt during the plastic coating process. The above conditions will produce plastic after the pipeline is put into use. With the phenomenon of layer shedding, the thick-walled steel pipe part of the pipeline was corroded and damaged in the later stage.
4. Thick-walled steel pipe mouth grinding: After cutting, an angle grinder should be used to grind the plastic layer of the pipe mouth. The purpose is to avoid melting or burning the plastic layer during flange welding and destroying the pipe. Use an angle grinder to polish the plastic layer of the nozzle.
passivity to form a protective film on the surface. Thick-walled steel pipes have high hardenability, good machinability, moderate cold deformation plasticity, and weldability; also, the toughness of steel is not much reduced during heat treatment, but it has quite high strength and wears resistance, especially when it is water quenched. It has high toughness; but this steel is highly sensitive to white spots, has a tendency to temper brittleness and overheating sensitivity during heat treatment, has high strength and hardenability, good toughness, small deformation during quenching, and high creep strength at high temperatures And long-term strength. It is used to manufacture forgings that require higher strength than 35CrMo steel and a larger quenched and tempered section, such as large gears for locomotive traction, supercharger transmission gears, rear axles, connecting rods and spring clamps that are heavily loaded. It can also be used drill pipe joints and fishing tools for oil deep wells below 2000m and can be used as molds for bending machines.
Post time: Nov-22-2023