Differences between seamless elbows and welded elbows

According to the fluid direction of the pipelines, steel elbows can be divided into different degrees, such as 45 degree, 90 degree,180 degree, which are most common degrees. Also there has 60 degree and 120 degree, for some special pipelines. 

According to the raw material, the steel pipe elbows can be divided as seamless pipe elbow and welded pipe elbow. Here we’d like to share some knowledge about the seamless steel elbow and welded steel elbow. 

Seamless elbows are made of seamless steel pipes through hot pushing, pressing or extrusion processes, and there are no welds on the elbows.
In general, welded elbows smaller than DN600 are made of welded steel pipes, are made in the same process as seamless elbows. But there is a welded seam on the elbows. Welding elbows larger than DN600 are made of steel plates, and there will be 2 welds. If you need the seamless elbows when the size is above DN600, please inform in advance, we can also produce them.

JS FITTINGS will show you the difference between seamless elbows and welded elbows in raw materials, manufacturing process, performance, appearance, size, application, cost and price.

The production of seamless elbows mainly uses hot pushed technology.The hot pushed elbow forming technology is to use special elbow pushing system core machine, mold and heating device, to set on the mould of billet in pushing forward movement, under the impetus of the machine in motion is heated and hole enlargement and forming process. 

The hot pushed elbows have a good appearance, uniform wall thickness and continuous operation, they are suitable for the characteristics of mass production. Thus, the hot pushing technology becomes the main forming methods of carbon steel, alloy steel elbows, and also applied in some specifications of the stainless steel elbows.

The raw materials of welded elbows are welded steel pipes and steel plates. Normally, the elbows’ diameter below DN600 are produced by welded steel pipe. The diameter more than DN600 requires steel plates. The first step of producing the welded elbow is bending the steel plates, then welded into circular. Welded steel elbows have the characteristics of high production efficiency, low cost and saving material.