DIFFERENT TYPES OF PIPE MANUFACTURING.

By Sindhur raju.T

There are different types of pipe manufacturing methods. Some of them are..

∙ Seamless pipe.∙ Metal Extrusion.∙ Centrifugal casting.∙ Electric resistance welded pipe.

Seamless pipe manufacturing process:

◑ In this a solid round (billet) is used. It is heated in a rotary heating furnace and then pierced by a piercer.◑ The pierced billet  is rolled by a mandrel mill to reduce the outside diameter and wall thickness which forms a multiple length mother tube.

Extrusion:

Extrusion is a process used to create objects of a fixed cross-sectional profile. A material is pushed or pulled through a die of the desired cross-section.

Metal extrusion◑ A work piece of a certain length of cross section is forced to flow through a die of smaller cross sectional area.

Extrusion process can be done in 4 ways:◑ Hot Extrusion.◑ Cold extrusion.◑ Direct extrusion.◑ Indirect extrusion.

Hot extrusion

◑ Involves working a metal above its recrystallization temperature. ◑ Generally preferred for larger parts, more extreme changes in shape and for more complex geometry

Cold extrusion

Cold extrusion of metal is usually used for smaller parts, less complex shapes, more workable materials

Direct Extrusion:

In this work billet is contained in a chamber the RAM exerts force on one side of work piece.

Direct extrusion of hollow pipe:

 With the use of a mandrel attached to the dummy block. A hole is created through the work, parallel to the axis over which the ram applies the force to form the extrusion.

Indirect extrusion:

In this process the work piece is located in a chamber that is completely closed off one side,and die is forced from other end.

Indirect extrusion of hollow pipe:

In this process, a ram is forced into the work material. The ram gives the internal geometry to the tubular part, while the material is formed around it. 

Centrifugal casting:

It is a technique that is typically used to cast-thin walled cylinders and for high quality results.

In centrifugal casting, a permanent mold is rotated continuously about its axis at high speeds (300 to 3000 rpm) as the molten metal is poured.

The molten metal is centrifugally thrown towards the inside mold wall, where it solidifies after cooling.

Electric resistance welded pipe:

It is manufactured by a sheet of steel into a cylindrical shape.

Current is then passed between the two edges of the steel to heat the steel to a point at which the edges are forced together to form a bond without the use of welding filler material.