What should be done for X-ray inspection of spiral steel pipes? 2024-12-19

According to the industry standard for spiral steel pipes, whether it is a standard spiral steel pipe or a national standard spiral steel pipe, it must undergo flaw detection testing. Some comrades have said that the standard for spiral steel pipes (SY/T5037-2012) is also used? In fact, it's because you don't really understand the Ministry Standard. The Ministry Standard originated from the first production line in China in 1956, which was based on the standards of the former Soviet Union. Although the standard was low, there were requirements for inspection, such as 20% X-ray spot detection. In a sense, it basically meets the production requirements. Generally speaking, the medium conveyed by the Ministry Standard spiral steel pipe is sewage and drinking water. In terms of welding quality, the Ministry Standard spiral steel pipe is pressurized to ensure no water leakage, and X-ray spot detection ensures that the weld is qualified.

What is the process flow of Mengcun large-diameter spiral steel pipe? 2024-12-19

Large caliber spiral steel pipe is a spiral seam steel pipe made of strip steel or rolled plate as raw material, often formed by warm extrusion, and welded by automatic double wire double-sided submerged arc welding process Below is a brief introduction to the manufacturing process of large-diameter spiral steel pipes: The raw materials are strip steel coils, welding wire, and flux. Strict physical and chemical tests must be conducted before investment. The head and tail of the strip steel are connected by single or double wire submerged arc welding, and automatic submerged arc welding is used for repair welding after being rolled into a steel pipe. Before forming, the strip steel undergoes leveling, trimming, planing, surface cleaning, conveying, and pre bending treatment. The use of an electric contact pressure gauge to control the pressure of the oil cylinders on both sides of the conveyor ensures the smooth transportation of the strip steel. Adopting external or internal control roller molding. Adopting a weld seam gap control device to ensure that the weld seam gap meets the welding requirements, the pipe diameter, misalignment, and weld seam gap are strictly controlled. Both internal and external welding are carried out using American Lincoln welding machines for single or double wire submerged arc welding, in order to achieve stable welding quality. The welded seams are all inspected by an online continuous ultrasonic automatic damage tester, ensuring 100% non-destructive testing coverage of spiral welds. If there is a defect, it will automatically sound an alarm and spray a mark, and production workers will adjust the process parameters accordingly to eliminate the defect in a timely manner. Use an air plasma cutting machine to cut steel pipes into individual pieces. After cutting into individual steel pipes, each batch of steel pipes must undergo a strict initial inspection system to check the mechanical properties, chemical composition, fusion condition, surface quality of the welded joints, and undergo non-destructive testing to ensure that the pipe manufacturing process is qualified before it can be officially put into production. The parts with continuous ultrasonic testing marks on the weld seam shall be manually inspected by ultrasonic and X-ray. If there are indeed defects, they shall be repaired and undergo non-destructive testing again until it is confirmed that the defects have been eliminated. The pipes where the welded joints of the strip steel and the T-shaped joints intersecting with the spiral welds are located are all inspected by X-ray television or film. Each steel pipe undergoes a hydrostatic pressure test, and the pressure is sealed radially. The test pressure and time are strictly controlled by the steel pipe water pressure microcomputer detection device. Automatic printing and recording of experimental parameters. Mechanical processing of pipe ends to accurately control the perpendicularity, slope angle, and blunt edge of the end face. Although affected by the economic crisis, the large-diameter spiral steel pipe company is recovering and developing, welcoming a better tomorrow. Large diameter spiral steel pipes have played a significant role in the transportation of gas.

Introduction to the standard of 3PE anti-corrosion spiral steel pipe 2024-12-19

If anti-corrosion steel pipes are classified according to their types, they can be mainly divided into several forms: anti-corrosion spiral steel pipes, anti-corrosion straight seam steel pipes, and anti-corrosion seamless steel pipes. The common form of anti-corrosion steel pipes on the market now is 3pe anti-corrosion. The SY/T0413-2002 standard has been implemented domestically since August 1, 2002. The standard mainly specifies polyethylene and high-density polyethylene, with a Vicat softening point set at not less than 110 ℃; The thickness of the external anti-corrosion layer is determined according to the German standard DIN30670-1991, which mainly uses low and medium density polyethylene. Improved the impact resistance of the 3PE anti-corrosion coating. SY/T0413-2002 significantly improves the peel strength and impact resistance indicators of the 3PE anti-corrosion layer, and specifies that based on the carbon black content of some special materials, the mechanical strength and weather resistance of the 3PE anti-corrosion layer have been improved, and the sampling frequency of the joint peeling strength (i.e. the peeling strength of the heat shrink sleeve and heat shrink tape to the primer steel) has been increased. The anti-corrosion spiral steel pipe 3PE structure anti-corrosion coating combines the advantages of high-density polyethylene coating and fusion bonded epoxy powder. The epoxy powder of this system is firmly bonded to the surface of the steel pipe, utilizing high-density polyethylene to resist mechanical damage. The special adhesive layer between the two layers forms a composite structure of molecular bonds, thereby achieving a good combination of anti-corrosion and mechanical properties.

Research on Spiral Pipe Fracture in Hebei Spiral Steel Pipe Factory 2024-12-19

In the current steel pipe industry, there is a lot of further research on the fracture of straight seam pipes, but there is very little research on spiral welded steel pipes, which will take several years. Foreign countries are also starting to do this work, but it has not been introduced to China. The steel pipe factory mainly produces spiral steel pipes. The buried steel pipes nowadays are all spiral steel pipes, so the problem of spiral steel pipe rupture is very serious. So there is very little research on the rupture of spiral steel pipes abroad, mainly due to two reasons: one is that the application of spiral pipes and straight seam pipes is very limited, especially in the study of rupture of important tracheal lines; Another issue is that the study of steel pipe rupture is very rare, so the results of straight seam pipe research are often applied to spiral steel pipes. The research on the rupture of spiral steel pipes is still in its infancy. The characteristics of spiral steel pipe rupture: Samples are taken from different directions of the steel pipe, and then subjected to tensile and Charpy impact tests; For pipelines, the maximum principal stress is the circumferential stress, and the direction of maximum driving cracking is generally along the axial direction. But for straight seam pipes, the direction of maximum driving cracking and the minimum resistance to fracture are consistent; Defects in welded pipes are difficult to detect in raw materials, usually in the weld seam or heat affected zone, but their two defects are consistent with the weld seam. The defect direction of straight seam pipes is axial, while the defect direction in spiral pipes is oblique. In general, although the tensile test results of spiral steel pipes are basically independent of the sampling direction, if it is a Charpy impact test, it is closely related to the sampling direction; The difference between the rupture of a spiral tube and a straight seam tube is that for a straight seam tube, the driving direction of rupture or expansion must be along the axis and must be mutual. However, for spiral tubes, the direction of maximum driving force and minimum resistance for rupture and expansion is not consistent.

对于螺旋钢管的防腐除锈具体该如何做？ 2024-12-19

　　（1)现场宜采用除锈机除锈。除锈作业中，应根据环境状况采取防噪音、降尘和消防措施。除锈机应有防护罩，周围不得有易燃物。 　　（2)施工现场不宜使用喷砂除锈。现场需使用时，应采用真空喷砂、湿喷砂等，且必须采取除尘和隔音措施，并在操作范围内设安全标志。 　　（3)人工除锈时，应按规定佩戴口罩、眼镜、手套等劳动保护用品；场地应平整，通风良好；管子应挡掩牢固，不得在不稳定的管身上除锈。

大口径螺旋钢管的焊接该如何做？ 2024-12-19

　　焊接神舟大口径螺旋钢管首先清理干净焊口的油，漆，水，锈等，然后根据壁厚开坡口，厚的就开大一些，薄的就开小一些(角磨机)，然后就是对口的缝隙，一般是焊条或焊丝直径的1-1.5倍，如果你坡口不小心开大了话可以适当留小一些。点固焊至少三点，一般四点比较好干活。 　　焊接神舟大口径螺旋管的时候应该一半一半焊接，起点最好超过最底点一公分左右，那样从对面好接头。如果钢管壁厚的话，应该分层，至少两层，第一层整圈焊完才可以焊第二层。

螺旋钢管在管道运输方面有哪些应用 2024-12-19

　　随着社会的发展，现在随着海洋油气开发，海底管道得到了飞速的发展，这当然对管道的要求越来越高。螺旋管直径大，强度高，螺旋钢管实用的特点使它成为很多长距离管道选择管道。事实上，螺旋管管道运输具有许多优点，有一个缺乏体积应变能力。只是凝固点高，含蜡原油，高于设计输量，将现有的管道承压能力和抽水能力的限制；低于设计，将现有的管道热力条件。为了克服固定点，只有在减阻剂和降凝剂。目前，中国的二管道工业的发展高峰会。螺旋钢管的发展也将投资，提高管道运输能力。 　　随着螺旋管强度的增加和直径的增加，由于缺乏认识的重要性，冲击韧性，在世界很多地方都有脆弱性和弹性的管道破裂事故。管钢管焊管韧性指数实际上已经成为一个重要指标。螺旋焊管韧性裂纹的失稳扩展和失稳扩展。如何避免管道断裂的方法，对基地和焊接金属压扁试验，弯曲试验，跌落试验，冲击试验和许多其他的韧性指标。不仅对管道具有高韧性的要求，近年来该行还提出了更高的冲击韧性要求。长距离管道，避免裂缝是非常困难的，螺旋钢管事实上在国内和国外都很难做到。这是因为管道数百公里甚至超过1000公里长，焊接，焊嘴太多，加上建筑和运输过程中造成的损害等，使建筑和风险增加。

地下自来水用哪种防腐钢管质量好 2024-12-19

　　目前我国对于地下自来水输水管道都要求进行防腐，目前TPEP防腐钢管是作为输水管道好的一种防腐钢管。自来水输水管道外壁防腐主要有3PE防腐和环氧煤沥青防腐两种，不管从质量还是防腐效果及使用寿命方面3PE防腐效果都是好的，内壁防腐主要是应用IPN8710无毒防腐涂料，TPEP属于内壁和外壁防腐的组合产品。

防腐钢管的重要性及优势 2024-12-19

　　防腐钢管在人们的日常生活中扮演着重要的不同的角色，防腐钢管一般指的是采用特殊的工艺对普通的钢管进行防腐化处理，使钢管具有一定的防腐蚀能力，一般还是用于防水、防锈、防酸碱、防氧化等特性，一般所说的PE防腐钢管指的就是聚乙烯防腐钢管，就是利用先进的科学和工艺加工而成的管状物品，PE防腐钢管广泛的应用在石油、天然气、城市燃气、城市供水、水煤浆输送管线等方面。 　　根据需求的不同还可对钢管内外壁进行相对应的防腐措施，常见的主要有环氧煤沥青防腐钢管、聚氨酯类涂料防腐、防腐钢管内壁水泥砂浆防腐等，防腐钢管主要应用在有特殊要求或者恶劣环境中的工程领域。 　　防腐钢管是指经过防腐工艺加工处理，可有效防止或减缓在运输与使用过程中发生化学或电化学反应发生腐蚀现象的钢制管道。根据我国统计数据，每年国内的钢管腐蚀直接经济损失2800多亿，当前全球每年因钢管腐蚀损失高达5000亿美元。防腐钢管可有效地防止或减缓腐蚀延长钢管的使用寿命，降低钢管运行成本。防腐钢管的特点，耐腐蚀、不泄露、高韧性、具有优良的挠性、具有良好的抵抗刮痕能力、具有良好的快速裂纹传递抵抗能力，在一个就是防腐钢管的使用寿命厂，在大于等于60摄氏度的环境下可以使有50年以上的寿命。 　　钢管通过防腐除了提高了钢管的使用寿命外，具体还表现在以下几个方面： 　　1、结合钢管的机械强度和塑料的耐蚀性于一体。 　　2、外壁涂层达2.5mm以上，耐划伤、耐磕碰。 　　3、内壁摩阻系数小，0.0081-0.091，降低能耗。 　　4、内壁光滑不易结垢，具有自清洁功能。