Definition, classification and technical requirements of elbow


Elbow (elbow): in the pipeline system, the elbow is to change the direction of the pipe fittings.

Elbow classification: according to the angle, there are 45 degrees and 90 degrees 180 degrees three most commonly used, in addition, according to the needs of the project also includes 60 degrees and other non normal angle bend.

The elbow materials of cast iron, stainless steel, alloy steel, cast iron and carbon steel can be calcined.

The connection between the pipe and the pipe is: direct welding (the most common way) flange connection, threaded connection with socket connection, etc..

According to the production process can be divided into: welding elbow, stamping elbow, casting elbow, etc..

Pipe fitting used in the installation of a pipe, for the connection of the pipe bend.

Purpose: connect two nominal diameter of the same or different pipe, so that the pipeline for a certain angle turn.

1 material is divided into: carbon steel, cast steel, alloy steel, stainless steel, copper, aluminum alloy, etc.. (but the wooden factory is pure forging)

2 division of the production method can be divided into: pushing, pressing, forging, casting, etc.. (now it's usually pure).

3 makes the standard can be divided into: GB, standard, water, electricity, American Standard German standard, Japanese standard etc..

4 according to its radius of curvature to divide: can be divided into long radius elbow and short radius elbow. Long radius elbow refers to its radius of curvature is equal to 1.5 times the diameter of the tube, that is, R=1.5D. Short radius elbow means that the radius of curvature is equal to the outer diameter of the pipe, that is, R=1.0D. (D is the diameter of the elbow, R is the radius of curvature).

5 if according to the pressure level, about 17 kinds, and American Standard pipe is the same: sch5s, sch10s, sch10, sch20, sch30, sch40s, STD, sch40, sch60, sch80s, XS; sch80, SCH100, sch120, sch140, sch160, XXS. The most commonly used is two kinds of STD and XS.

Technical requirements: 1 because most of fittings for welding, in order to improve the welding quality, end vehicles into the groove, leave a certain angle, with boundary, this requirement is quite strict, edge thick, at an angle of number and range of deviation is provided. The surface quality and mechanical properties are basically the same as that of the tube. In order to convenient welding, steel pipe and the connecting pipe are the same.

2 is all the pipe fittings should be through the surface treatment, the inner and outer surface of the oxide scale through shot blasting, and then coated with anticorrosive paint. This is for export needs, in addition, in the country is to facilitate the transport to prevent rust oxidation, to do this work.

3 is the packaging requirements for small pipes, such as export, you need to do wooden box, about 1 cubic meter, this provision in the case the number of elbows about not more than a ton, the standard allows the suit, large sets of small, but the total weight usually do not more than 1 ton. For large y to a single package, like 24 "must be a single package. The other is labeled packaging, labeling is to indicate size, number, batch number, manufactu