Views: 10 Author: Site Editor Publish Time: 2023-12-22 Origin: Site
Elbows are used to change the direction of the pipeline.
Commonly used elbow bending angle of 90°, 45° and 180°. 180° elbow is also known as the U-shaped elbow, there are also special angles of the elbow, but the number is very small.
Mar steel elbow, also known as malleable iron elbow, is the most common threaded elbow.
The sizes of marmoleum elbows are relatively small, commonly ranging from 1/2 to 4 inches, and are galvanised and un-galvanised according to their different surface treatments.
This kind of Mar steel fittings, mainly used in heating, water and sewerage pipes and gas pipes. It is seldom used on other material pipelines except for low pressure pipelines which need to be dismantled frequently during the process.
Pressed elbow, also known as stamping elbow or seamless elbow, is made of high-quality carbon steel, stainless acid-resistant steel and low alloy steel seamless pipe, etc., pressed in a special mould.
○ Its bending radius is one and a half times the nominal diameter (R = 1.5D), in special occasions can also be used to bend the radius equal to the nominal diameter of the elbow (R = 1D).
○ Its specification range in DN20 ~ 600mm.
○ Its wall thickness range is consistent with the table number of seamless steel pipe.
○ Pressed elbow generally by professional manufacturers or processing plants with standard seamless steel pipe stamping and processing, factory elbow should be processed at both ends of the bevel.
Stamping welded elbow, is the use of sheet metal by the mould stamping into half a ring elbow, and then the two half-ring elbow for group welding.
Its bending radius is the same as the seamless pipe elbow, the specification range for the nominal diameter of 200mm or more.
Welded elbow, also known as shrimp waist or shrimp body elbow.
There are two methods of production:
○ One is in the processing plant with steel plate undercut, cut and rolled welded to shape, most of them are used for the matching of steel plate coil pipe.
○ The other is to use the pipe material down, by grouping welding moulding, its specifications are generally more than 200mm. The use of temperature can not be greater than 200 ℃, generally can be made at the construction site.
High pressure elbow, is made of high quality carbon steel or low alloy steel forging.
According to the form of pipeline connection, the elbow ends are processed into threads or bevels, the precision of the processing is very high, the requirements of the pipe mouth threads and flange mouth threads can be closely matched to the free screwing and shall not be loosened.
Applicable to the pressure of 22.0, 32.0MPa petrochemical pipelines, commonly used specifications range from DN6 to 200mm.
