Cangzhou City Dongtai Steel Pipe Co., Ltd. sales manager left Yu Peng: 18730700585 [(OD - Wall Thickness) * thickness] * 0.02466 = kg / m (weight per meter) double submerged arc welded straight seam steel 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 full-board ultrasonic testing; Milling: Milling Machine on steel edge-sided milling, so that meet the requirements of the plate width, and a plate parallel to the sides and the shape of the groove; c pre crimping: pre-bending machine for pre-bent plate edge, the plate edges have to meet the requirements of the curvature; d. molding: JCO molding machine on the 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" shape, and finally form an opening "O"-e. presoldering: so after forming a straight seam welded steel pipe seam continuous welding and gas shielded arc welding (MAG); f within welding: tandem multi-wire submerged arc welding (up to four wire) column multi-wire submerged arc welding; g Weld: straight seam steel pipe inside LSAW steel pipe outside of welding; ultrasonic testing Ⅰ: straight seam welded steel pipe inside and outside the weld and weld on both sides of the base material of 100% inspection; i X-ray inspection Ⅰ: internal and external welds 100% ray TV check image processing system to ensure that the testing sensitivity; 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 by the root test in order to ensure reach the standard required test pressure steel pipe machine with automatic recording and storage capabilities; l chamfering: the size of the pipe end beveling of pipe end processing, to meet the requirements of the test after passing the steel pipe; m Ultrasonic Inspection II: again gradually root ultrasonic inspection to check straight seam welded steel pipe in flaring defects that may arise after the water pressure; n X-ray inspection II: ray industrial TV inspection and tube end weld steel pipe expanded diameter and hydrostatic testing shoot tablets; o. magnetic particle inspection of the tube ends: this inspection to detect defects of the pipe end; 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: steel pipe diameter: Ф325 ~ Ф1220mm (12-48in