Stainless steel pipe fittings, stainless steel elbows use the problems in the standard.

1. Safety and economy

In addition to the above-mentioned description, there are other types of pipe fittings used in the actual piping project to meet the requirements of various working conditions, especially special working conditions. In engineering design or selection, the higher the strength grade of the pipe fittings, the higher the safety, but the higher the cost of the project, which will cause unnecessary waste.

From the perspective of economic efficiency, while meeting the engineering design requirements, the cost is reduced as much as possible, but it is often easy to form the result of a small number of varieties in the selected pipe fittings, which is not conducive to the management, regulation and design changes of the on-site construction materials. Material substitution, etc. Therefore, the selection of pipe fittings should be comprehensive safety and economy, and it is advisable to reduce the variety of pipe fittings as much as possible. In addition, the conditions of on-site construction, the level of construction, the procurement cycle of pipe fittings, etc., should also attract the necessary attention in the selection of pipe fittings. In specific cases, the possibility of strengthening the pipe joints, the miter bends, and the field bending of small-diameter pipes should also be considered. At the same time, it is necessary to understand the production capacity and products of the pipe fittings and the market supply.
2, the problems in the selection of stainless steel pipe fittings
1. The domestic pipe fittings standards are not perfect, and the unsupported pipe fittings standards should include the type parameter standards of pipe fittings and the pipe fitting material standards. However, the material standards are either incomplete or lack of quality technical requirements such as ordering requirements, inspection and assembly rules, and quality certification. Pipe fitting materials have poor standard matching, and are often formulated from their respective positions and angles rather than from the entire standard system of pressure piping. In the selection of the project, the pipe standard is available, but there is no corresponding forging or casting standard. The reality is that the standard for pipe fittings forgings uses the forgings of pressure vessels, and does not consider the differences between the two, such as welding, film inspection and other regulations.
2, the standard level of pipe fittings varies widely, the content lacks consistency and systemicity, and even the convergence of contradictions, resulting in inconvenience in use.
3. Type test standards for non-pipe fittings. Only the GB12459 and GB13401 standards specify the pressure calculation for the blasting test of steel butt welded seamless pipe fittings and steel plate butt welded pipe fittings. Other types of test standards or implementation standards that guarantee the quality of pipe fittings manufacturing are not available. .

Steel metal pipe fittings are available in various forms to meet different applications and conditions. The most used ones are elbows, tees and reducers. Pipe fittings are commonly used for butt welding, socket welding, and pipe threading. Generally, the pipe with DN50 and above adopts the butt welded connecting pipe. The pipe below DN50 adopts the type of socket welded pipe fitting or threaded connecting pipe fitting and sealing welded pipe fitting. Firstly, it should be based on the design pressure of the piping system, the design temperature and the nature of the medium in the pipe. Secondly, considering the comprehensive factors such as economy and longevity, and determining the use pressure and temperature level of the pipe according to the design pressure and design temperature of the pipe system in which it is located. When the branch pipe is used to connect the pipe from the main pipe, if the pipe diameter is the same, the three-way connection should be used as much as possible; when the pipe diameter is less than or equal to DN50, in the range of the three-way variable diameter or outside the applicable range, the branch pipe and half are selected. Pipe joints such as pipe joints or reinforced pipe joints are connected to the pipe fittings; in addition, depending on the specific conditions of the project, the structure of directly welding the branch pipes on the main pipe may be used, but it is necessary to check whether the branch pipe joints need to be reinforced.