SSAW Pipe

　　27MnCrV is a new type of steel used in the production of TP110T steel grade casing pipe sleeves. The steel types used in conventional production of TP110T steel grade oil pipe sleeves are 29CrMo44 and 26CrMo4. Compared with the latter two, 27MnCrV contains less Mo, which can greatly reduce production costs. However, after the 27MnCrV is produced by the normal austenitizing quenching process, there is obvious high temperature tempering brittleness, which results in low impact toughness and instability. 　　To solve such problems, two methods are usually used to deal with them. First, rapid cooling after tempering is used to avoid high temperature brittleness and obtain toughness. The second is the sub-temperature hardening method through the incomplete austenitization of steel to effectively improve harmful elements and impurities, and improve toughness. The first method has relatively strict requirements on heat treatment equipment and requires additional costs. 　　27MnCrV steel ha...

　　The casing pipe coupling is a kind of oilfield drilling tool, which is mainly used for the connection of the oil pipe, and mainly solves the problem that the existing coupling easily generates fatigue fracture due to stress concentration. 　　The tubing coupling structure is: the tubing end is connected to the inner wall of the coupling by a taper thread, and the end of the coupling body and the oil pipe are connected by the same thread with the pitch flat thread. The utility model has the characteristics of alleviating the stress concentration of the root of the external thread of the single taper thread connection tubing, is not easy to produce fatigue fracture, and has good connection effect. Effectively prevent oil well pipe string breakage accidents. 　　The coupling is divided into a tubing coupling and a casing coupling. Commonly used steel grades are J55, K55, N80, L80, P110 and so on. 　　Main buckle type: NU (not thickened), EU (thickened), TBG (not thickened), UP-TBG (thic...

　　Today, Great Steel Pipe will share the connection modes of oil pipelines for all of you. Oil pipeline must use a certain connection to form a complete system. Connection methods of pipeline are mainly three categories, including screw thread, welding and flange connection. 　　When the pressure is not high, the pipe with small diameter can be connected by using screw thread this method. This connection method is very convenient, but most of the diameter of oil pipelines are generally larger, so other two connection methods are used commonly. The pipeline that DN≥50 basically uses welding method to connect. Welding has many advantages, such as convenient construction, strong, tight and saving steels. The general straight pipe or bends those parts do not need to tear down can use this method. 　　The connection of pipes and valves or other equipment (such as: pump) and the parts those need to disassemble of pipeline need to use flange to connect. In order to ensure the tightness of th...

　　LSAW steel pipes have several flaw detection tests. LSAW steel pipes are now used more and more widely. According to different projects, the standards for using steel pipes are also different. 　　Generally speaking, steel structures, piling, sewage discharge pipes, etc. There is no requirement for flaw detection of steel pipes, no need for flaw detection, and the projects used for flaw detection are: natural gas pipelines, oil pipelines, fire pipelines, etc. These projects have extremely strict requirements for flaw detection, and some strength flaw detection standards are related to The safety of the project is even related to the safety of people's lives. 　　There are two types of flaw detection that are most widely used. One is ultrasonic flaw detection. This type of flaw detection is to use ultrasonic energy to penetrate into the depth of the metal material and to reflect at the edge of the interface when one section enters another section. A method of part defect, when the...

　　During the construction of natural gas and oil pipeline stations, the installation of valves, meters and flanges should be tapped in the main channel. It is difficult to identify the straight seam position of the base pipe by high-frequency resistance welding. The installation of some lugs is very close to the welding seam. Therefore, it is very necessary to deeply study and analyze the influence of the boss on the basic pipeline. In this paper, the residual stress distribution of high frequency longitudinal resistance welded pipe is analyzed, and the influence of welding position of different boss on residual stress is analyzed. The stress increases sharply and the longitudinal welding residual stress is affected when the boss installed on the ERW pipe is much larger than the parent pipe. 　　ERW pipeline 　　The distribution of residual stress in welded pipe is closely related to the forming process. HFW resistance welding is the cross section of a circular tube after rolling, whic...