Forming Process of Steel Bends and How to Prevent the Aging of Steel Bends

First, Steel Bend Processing

1. Die Forging. For socket weld and threaded tees, crosses, elbows, and other small steel pipe fittings with more complex shapes, die forging should be used. The die forging blank should be a rolled profile, such as bar stock, thick-walled steel pipe, or plate. When using steel ingots as raw materials, the ingots should be pre-rolled into strips or used as die forging blanks after forging to eliminate segregation, porosity, and other defects in the ingots. After heating, the blank is placed in the forging die, and pressure forces the metal to flow and fill the die cavity. Flash evaporation will occur after the blank is forged, and the remaining flash evaporation material needs to be washed away to complete all forging work.

2. Free Forging. Steel pipe fittings with special shapes or unsuitable for die forging can be manufactured through free forging. The general shapes of steel pipe fittings should be free forged; for example, tee branches should be forged.

3. Machining. For certain tubular steel pipe fittings, such as double-socket joints and movable joints, they can be directly processed from bars or thick-walled steel pipes. During processing, the fiber flow direction of the metal material should be approximately parallel to the pipe's axial direction. For tees, crosses, elbows, and steel pipe fittings, direct cutting from bars is not permitted.

Second, methods to prevent the aging of steel bends.

There are many types of steel bends, and they are used in various environments and come into contact with many materials. The lifespan of a pipe mainly depends on its anti-aging ability. Due to material limitations, the anti-aging effect of some pipes may not be significant. The following methods can achieve anti-aging effects:

1. During the laying process, overcoming axial deformation caused by seasonal temperature differences and controlling thermal expansion are crucial.

2. When connecting hot-melt-welded pipes to metal pipes and cement pressure pipes, the bends should be firmly bonded. This prevents changes in axial force due to material temperature variations, which could affect sealing performance. The serpentine laying of hot-melt-welded pipes should be within the planned allowable range to accommodate pipe temperature changes.

3. Blue or black tubing can be used to squeeze blue ribbons; the latter typically has better UV resistance and anti-aging properties. Protective sleeves are also recommended for public use. Pipes should be protected from direct sunlight during transportation and storage, and on-site exposure should be very short.

Therefore, when using steel bends, users should also try to prevent pipe aging, such as avoiding sunlight exposure and wrapping the pipes with anti-corrosion tape to protect their lifespan.