Cangzhou City Dongtai Steel Pipe Co., Ltd., sales manager at Zhiqiang: 15932715956 0317-6289066 13393378282 (OD - Wall Thickness) * thickness] * 0.02466 = kg / m (weight per meter) double submerged arc welded pipe joints straight main process description: double submerged arc welded straight seam steel pipe [1] a board probe: used to manufacture large-diameter straight seam submerged arc welded steel plate into the production line, the first ultrasonic inspection of the entire board; Milling: through the edge milling sided milling machine on the two edges of the steel plate, so that to achieve the required plate width, the degree of parallelism of the plate edge, and the groove shape; c pre-bent edge: the use of the pre-bending machine to pre-bent plate edge, the plate edges have found curvature requirements; d molding: in JCO molding machine first half of the pre-bending a steel plate after after repeated stepping stamping, pressed into a "J" shape, and then the steel sheet the same manner as in the other half bent, pressed into a "C" shaped straight seam welded steel pipe, the last "O" to form an opening the form e presoldering: the molding seam continuous welding and gas metal arc welding (MAG); f. the inner welding: tandem multi-wire submerged arc welding ( up to four wire) g Weld: tandem multi-wire submerged arc welding outside; LSAW steel pipe h ultrasonic testing Ⅰ: straight seam welded straight seam steel pipe inside of welding; steel pipe inside and outside the weld and weld on both sides of the base material 100% inspection; i X-ray inspection Ⅰ: internal and external welds 100% ray TV check image processing system to ensure sensitivity testing; j. expanded diameter: the LSAW steel full length enlarged diameter in order to improve the accuracy of the size of the steel pipe, and to improve the distribution state of the steel pipe inner stress; k hydrostatic test: on the hydrostatic testing machine after the enlarged diameter steel pipe Hourly root test to guarantee to reach the standard required test pressure steel pipes, the machine automatically record and store; l. the chamfer: steel pipe inspection pipe end processing, to meet the requirements of the pipe end beveling size; m ultrasonic inspection Ⅱ: once again by the root ultrasonic inspection to check straight seam welded steel pipe in flaring, defects may arise after the water pressure; n X-ray inspection II: ray industrial TV checks expanded diameter and hydrostatic testing of steel pipe and tube end weld filming; o pipe end magnetic particle inspection: this inspection pipe end to discover defects; p corrosion and coating: after passing the steel pipe corrosion and coating according to user requirements. In addition to the the testing items above, according to the special requirements of API standards and other relevant standards and some users also need to conduct detrimental to the inspection and testing of steel plate, steel pipes, including the sampling of the physical and chemical properties of raw materials into the plant, 100% of the steel plate appearance inspection . Double submerged arc welded straight seam steel pipe Specifications: