Twenty products of our country are applied to the submerged arc piping, which is applied to tap water engineering, the petrochemical industry, the chemical industry, the electric power industry, agricultural irrigation, and urban construction. In the forming process, the steel plate deformation is uniform, the residual stress is small, and the surface does not produce scratches. The processed spiral steel pipe has greater flexibility in the diameter and wall thickness of the size specification range, especially in the production of high steel grade thick wall pipe, especially small and medium diameter thick wall pipe has incomparable advantages, can meet the user in the spiral steel pipe specifications more requirements. All the equipment of the whole production line has the function of networking with the computer data acquisition system to realize real-time data transmission. The technical parameters in the production process are checked by the central control room. The double-sided submerged arc welding process can realize welding in a good position, and it is not easy to have defects such as wrong edge, welding bias, and incomplete welding, and it is easy to control welding quality. To check the quality of steel pipe, so that the whole process of steel pipe production is under the detection and monitoring, of the product quality.

Submerged arc steel pipe raw materials, namely strip coil, welding wire, and flux. Strict physical and chemical tests must be carried out before being put into operation. The welds after welding are inspected by an online continuous acoustic automatic damage instrument, and the non-destructive testing coverage of welds is determined. If there are defects, automatic alarm and spraying mark, production workers at any time adjust the process parameters, timely defects. Each steel pipe is tested by hydrostatic pressure and the pressure is sealed radial. The test pressure and time are strictly controlled by the microcomputer detecting device of steel pipe water pressure. Test parameters are automatically printed and recorded. Pipe end machining, so that the end faces perpendicularity, groove Angle, and blunt edge accurate control.

What are the production processes of submerged arc steel pipes?

(1) Internal welding: longitudinal multi-wire submerged arc welding (usually four wires) is used to weld the inner side of the straight steel pipe;

(2) Pre-bending edge: the pre-bending machine is used to prebend the edge of the plate so that the edge of the plate has the required curvature;

(3) Edge milling: the two edges of the steel plate are double-sided by the edge milling machine to achieve the required plate width, plate edge parallelism, and groove shape;

(4) External welding: longitudinal multi-wire submerged arc welding is used to weld the outer side of the spiral submerged arc welded steel pipe;

(5) Pre-welding: make the steel pipe after forming the joint and adopt gas-shielded welding (MAG) for continuous welding;

(6) Forming: in the JCO molding machine at first, half of the pre-bent steel plate after several steps of stamping, pressing into a J shape, and then the other half of the steel plate is also bent, pressed into a C shape, and then forming an open O shape;

(7) Plate probe: After the steel plate enters the production line, the first line of the whole plate special wave inspection;

The submerged arc steel pipe adopts an electric contact pressure gauge to control the pressure of the oil cylinder on both sides of the conveyor to ensure the smooth transmission of strip steel. The weld gap control device is used to meet the welding requirements, and the pipe diameter, the amount of the wrong side, and the weld gap are strictly controlled. The parts with continuous acoustic detection marks on the weld shall be reviewed by manual acoustic wave and X-ray. If there are defects, after repair, they shall be nondestructively tested again until the defects are confirmed. After cutting into a single steel pipe, each batch of steel pipe should be subjected to a strict first inspection system, to check the mechanical properties of the weld, chemical composition, melting condition, and surface quality of the steel pipe, and through nondestructive testing, tube making process qualified, before it can be formally put into production.

The main objects of X-ray inspection and special inspection for submerged arc steel pipe are butt joints of straight seam steel pipe and butt joints of butt welded pipe fittings. The non-destructive testing method is selected according to the design document. For titanium, aluminum, and aluminum alloys, copper and copper alloys, and nickel and nickel alloys welded joints, the X-ray testing method should be selected. For the welds with delayed crack tendency, the X-ray inspection and special inspection should be carried out after the corresponding welding cooling time. When there is a girth weld in the main pipe of the jacket, the weld should be tested by 1 ray, and concealed operation can be carried out after the pressure test is qualified. Welded joints covered by reinforcing rings or support plates on pipelines should be tested by 1 ray before being covered. For the welds that are required to be inspected in the middle of welding, non-destructive testing shall be carried out after the appearance inspection is qualified, radiographic and acoustic testing shall be carried out after the surface non-destructive testing, and the inspected welds can be continued to be welded after the evaluation.

Cangzhou Shenlong Pipe is specialized in the production of direct-seam submerged arc welding steel pipe, the product range is 406-3000mm, the maximum wall thickness of 60mm, product quality control is strict, fast delivery is the qualified supplier of PetroChina, BP oil.