Process flow of steel pipe production

A. Sample production: To facilitate inspection and ensure the manufacturing and installation accuracy of steel pipes and various pipe parts δ = 0.5mm

Galvanized steel plate fabrication template. According to the design requirements, steel pipe inner diameter radian inspection, support ring, stiffening ring, etc. must be made with sample plates

The arc length of the plate must meet the specification requirements (according to different pipe diameters, the arc length of the template is 1.5~2m). After the template is made

It must be checked by professional constructors and marked at the same time to prevent mixing during use. Bends and elbows are made of ground gauge and steel

Straight edge, etc. shall be set out directly on the spliced steel plate, and shall be checked by professional construction personnel, quality personnel or technical director before getting off

Material.

B. Steel plate splicing and blanking: according to the design requirements and in combination with the actual situation on site, all steel plates used for making steel pipes are fixed length steel

A little margin shall be reserved for the long and wide edges of the plate; To ensure that the circumference error of steel pipe is controlled within the minimum range, two fixed length plates are used

Cutting method after splicing; Carbon dioxide shielded welding process is adopted for splicing. Before splicing, check whether the side length is straight and wide

Whether the edge is perpendicular to the long edge. At the same time, trim the steel plate with an oxygen acetylene flame cutting blade to ensure that the width of the steel plate is consistent with the design

Slag, burr and notch on the cutting and planing surface shall be removed by grinding wheel, and the edge of all plates after processing shall be free of crack, interlayer and

Slag inclusion and other defects; Before welding, remove the rust, slag, oil stain, water stain, etc. within the range of 10~20 cm on both sides of the crater, and check

Welding can be carried out only after it is qualified; After the single side welding is completed, the steel plate shall be slowly turned over with a gantry crane, the back shall be gouged with an electric arc planer, and then polished

Continue welding.

C. The unfolded size of the spliced steel plate shall be determined according to the different thickness of the plate, and the unfolded drawing shall be drawn on the steel plate to carefully check the flatness

Line and diagonal lines shall be checked before blanking; The cutting edge of oxygen acetylene flame is used for cutting. Elbow, transition pipe and other pipe fittings

The blanking method of steel pipe is the same. First, use the computer to draw the flat development diagram of the bent pipe shell, and find out that each point is on the x axis and the Y axis

The chord length of each datum point will be obtained after the coordinate of; During actual lofting, butt two steel plates, with the length greater than the chord of the largest opening

The length and width are the expanded chord height of the small opening plus the actual height of the steel pipe. At the same time, each coordinate point is drawn on the steel plate to smoothly connect the coordinates

Check carefully whether the arc length at the connection between the branch pipe and the main pipe is the same, and then blanking can be carried out after checking.

D. After blanking, the groove at the weld shall be cut with oxygen acetylene flame, and then polished and shaped with angle grinder.