Elbow Definition, Categories and Technique Requirements

Nov 23, 2015

In the pipeline system, elbow is a pipefitting applied to change the direction of pipeline.

Elbow Categories:

1. Materials: carbon steel, cast steel, alloy steel, stainless steel, copper, aluminum alloy, etc.

2. Manufacturing methods: pushing, pressing, forging and casting, etc.

3. Radius of curvature: long radius elbow, whose radius of curvature is 1.5 times of elbow diameter, that is R=1.5D; while short radius elbow, whose radius of curvature is equal to elbow diameter, that means R=1.0D (D refers to elbow diameter, and R represents radius of curvature).

4. Ways connected with the pipe: directly welding, flange connection, thread connection and a socket type connection, etc.

5. Angle: 45°elbow, 90°elbow and 180°elbow are the most common used, and there are other abnormal elbow, such as 60°.

Technique Requirements:

1. Because most pipe fittings are used for welding, in order to improve the welding quality, its end will be designed to groove and leave a certain angle with a certain edge. This is stricter, the thickness, angle and deviation range all have rules. The surface quality and mechanical properties are almost the same with pipe. In order to convenient welding, pipe fittings and connected pipe steel is the same kind.

2. All the fittings should experience surface treatment, removing the internal and external surface iron oxide by shot blast, and then coating anticorrosive paint. This is for export demand, moreover, it need to be done to prevent corrosion in domestic for the convenience of transportation.

3. As for small parts, if it needs to be exported, a one cubic meter wooden case is required. It is stipulated that the amount of elbow in the cases should be no more than one ton. While large parts need single package, such as 24″type. Another factor is packaging mark, which should give clear indication of size, steel grade, batch number and manufacturer trademark.