Application of Electric Welded Steel Pipes for Low- and Medium-Pressure Boilers
Electric welded steel pipes have a wide range of industrial applications, and their use for low- and medium-pressure boilers is very common due to their reliability and economical cost. Steel pipes are used extensively throughout the boiler system, in piping and components that are subject to pressure and temperature forces. In addition to materials and welding considerations, the welding process, joint preparation, and joint design, among other factors all need to be carefully examined in order to maximize strength and quality.
The most commonly used steel pipes for boiler pressure systems are constructed in accordance with the American standard YB4102-2000. This type of pipe is constructed of a continuously-welded electric welded steel pipe. The dimensions of the pipe are in accordance with ANSI/ASME B36.10M. The pipe has an internal and external protective coating, which ensures good corrosion resistance.
In order to ensure the best quality of the welded joint, one must take into account the welding parameters, such as heat input and welding current. As per YB4102-2000 regulation the stress relief heat treatment is performed on the finished weld. This ensures that the residual stress in the assembled joints is relieved, thereby minimizing risks of mechanical fatigue due to external forces.
The joint preparation and joint design play a vital role in ensuring the quality and strength of the joint. As per YB4102-2000, the weld joint preparation and the joint design shall ensure that the weld metal can be deposited in a uniform and consistent manner, without creating pockets or any other irregularities. In addition, the joints are designed with a particular thickness in order to provide sufficient reinforcement, thereby increasing the strength and reducing the possibility of cracking or breakage of the pipe during extreme temperature or pressure conditions.
Once the joint has been prepared and the welding parameters have been determined, the weld must pass several quality tests to ensure its structural integrity. These tests include bending, non-destructive testing, hardness testing, tensile strength testing, and metallographic examinations. All welds must meet or exceed the requirements stated in YB4102-2000 to be deemed suitable for use in applications involving low- and medium-pressure boilers.
Finally, all welded joints of the electric welded steel pipes must undergo a series of visual inspections and, if necessary, radiography. This inspection is performed to evaluate any flaws or imperfections in the weld joint, in order to ensure the highest level of structural integrity and safety when used in a low- or medium-pressure boiler application.
In conclusion, electric welded steel pipes are widely used in various industrial applications, especially in the production of low- and medium-pressure boilers. The use of steel pipes helps to ensure reliable performance and economical cost of the boiler system. It is important to examine material, welding process, joint preparation, joint design and quality tests when using electric welded steel pipes for such applications to ensure their structural integrity and safety in boiler production.
