The Manufacturing Process of Seamless Pipe and Welded Pipe

Seamless Pipe Manufacturing Process

Seamless pipe is strongest amongst all pipes type as it has a homogeneous structure throughout pipe length. Seamless pipes are manufactured in a verity of size and schedule. However, there is a restriction on the manufacturing of large diameter pipe. Seamless pipes are widely used in the manufacturing of pipe fittings such as bends, elbows, and tees.

Mandrel Mill Process

In Mandrel Mill pipe manufacturing process, steel billet is heated to high temperature in the rotary furnace. A cylindrical hollow, which is also known as mother hollow, is produced with the help of a rotary piercer and set of roller arrangement that keeps the piercer at the center of the billet. Outside diameter of piercer is approximately that of the inside diameter of the finished pipe. With the help, secondary roller arrangement outside diameter and thickness are achieved.

Mannesmann Plug Mill Pipe Manufacturing Process

Mannesmann was German engineer who has invented this pipe manufacturing process. The only difference between Plug mill process and Mandrel mill process is that in mandrel method inside diameter is achieved in single pass whereas in Mannesmann multi-stage reduction is possible.

Forged Seamless Pipe Manufacturing Process

In a Forging pipe manufacturing process, a heated billet is placed in forging die that has a diameter slightly larger than the finished pipe. A hydraulic press of forging hammer with matching inside diameter is used to create cylindrical forging. Once this forging is done pipe is machined to achieve final dimension. Forging pipe manufacturing process is used to manufactured large diameter seamless pipe that cannot be manufactured using traditional methods. Forged pipes are normally used for the steam header.

Extrusion Processes

In an extrusion pipe manufacturing a heated billet is placed inside the die. A hydraulic ram pushes the billet against the piercing mandrel, material flows from the cylindrical cavity between die and mandrel. This action produces the pipe from the billet. Sometimes pipe manufactured produce pipe with a high thickness which is known as mother hollow. Many secondary pipes manufactured used this mother hollow to produce pipe with different dimensions.