General welded pipe: General welded pipe for conveying low pressure fluid. It is made of Q195, Q215A, Q235A steel and Q235B plain carbon. It is made of easy-welded 0317 standard model 6012 and soft steel mother 755. Pipe to carry out hydraulic, bending, flattening and other experiments, there are certain requirements for surface quality, usually delivery length of 4-10m, often require fixed-scale (or double-scale) delivery. The nominal caliber of welded pipe is expressed by nominal caliber (millimeter or inch). The nominal caliber of welded pipe is different from the actual caliber. There are two kinds of welded pipe according to the prescribed wall thickness: normal pipe and thickened pipe. The steel pipe is divided into two types, one is with thread and the other is without thread, according to the pipe end form.
Submerged arc welding (SAW) technology is adopted for longitudinal submerged arc welded steel pipe, filler welding and particle shielded flux SAW are adopted. The diameter of the pipe can reach 1500mm. LSAW is the abbreviation of submerged arc welded straight seam pipe. The production technology of submerged arc welded straight seam pipe includes JCOE forming technology and coil forming submerged arc welding technology. When the diameter is large, it may be rolled with two pieces of steel plate, which will form a double weld phenomenon. Executable standard GB/T3091-2008 low pressure fluid steel pipe production standards, GB/T9711.1-2-1997 petroleum and natural gas pipe production and use standards, but also can implement the United States API 5L pipeline steel pipe implementation standards. Production material: Q195A-Q345E; 245R; Q345QA-D; L245-L485; X42-X70. The pressure parameters are mainly 2ST/T, S is yield strength, and T is wall thickness. Submerged arc welding has developed into double wire submerged arc welding, as well as multi-wire submerged arc welding, further improving the efficiency.
