The principle of the number of membrane holes in oil pipe

　　(1) reasonable extrusion coefficient of oil pipe. According to the extrusion pressure of the extruder and the length of the feed table and the cooling table of the extruder, the size of the extrusion cylinder, the mechanical properties of the products and the requirements of the structure, the deformation resistance of the extruded alloy, etc. For aluminum alloy bar, it is advisable 8 - 40, of which the upper limit of soft alloy and the lower limit of hard alloy.

　　(2) the strength of the extruded mold is sufficient for the oil pipe. In order to improve the service life of dies, the distance between die holes and the distance between die holes should be kept constant. For the extruder less than 50MN, the lower limit is generally 15 - 50mm and the small tonnage extruder, and the upper limit of the large tonnage extruder is taken. For large extruders above 80MN, it should be increased to 30-80mm.

　　(3) good surface quality of API 5L Grade B X60 Carbon Steel Oil Pipe. In order to prevent the inflow of the ingot on the extrusion products, the minimum distance between the die hole and the edge of the extrusion cylinder should be kept, which is generally taken as the 10%-30% of the extruding diameter (the lower limit of the extruder and the upper limit of the small extruder). In addition, in order to prevent product surface scratches and sprains, reduce the labor intensity of workers and the amount of waste products, the number of holes can not be too many days.

　　(4) the flow of oil pipe is as uniform as possible.