Seamless Pipe Manufacturing Processes
In this video, you will learn about Seamless Pipe Manufacturing Process such as Mandrel Mill Process, Mannesmann Plug Mill Process, Forging Process and Extrusion Process that used to manufacture seamless pipe.
Mandrel Mill Process
In Mandrel Mill Pipe Manufacturing Process, steel billet is heated to forging 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 a finished pipe. With the help, secondary roller arrangement known as MPM -(Multi Stand Pipe Mill) outside diameter and thickness are achieved.
To maintain temperature, the pipe is sent to the reheating furnace that increases the temperature of the pipe. In next stage, the pipe is sent for the scratch reducing mill that improves dimension and surface finish of the pipe. After that pipe, the temperature is reduced to atmospheric temperature on cooling bed. These cooled pipes are then cut to the size and send for straightening. These finished pipes are then sent for various NDT inspection such as eddy current and ultrasonic inspection.
Once NDT is cleared, pipes are hydro tested to ensure strength and ability to remain leak proof under pressure. In the last stage of inspection, pipes are visually and dimensionally checked by competent inspection engineer. He will ensure that pipe is meeting the code, standard, and specification requirements. Once Inspection engineer cleared the pipe, it will mark as per standard requirements & send for packaging.
Mannesmann Plug Mill process
Mannesmann was German engineer who has invented this method. The 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. So you have greater thickness reduction as compared to Mandrel process. Here in this process chart, you can see the heat treatment furnace after the hydro test.
Stainless steel, low alloy steel, and higher thickness carbon steel pipes are subjected to various heat treatment such as Normalizing, Quenching, Tempering, Solution Annealing, Stress relieving or it is a Combination of this treatment. As explained earlier, a finished pipe is passed through various quality testing before it can be certified for use.
Forging Process to Manufactured Seamless Pipes
In a Forging process, a heated billet is placed in forging die that has a diameter slightly larger than a 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 is used to manufactured large diameter seamless pipe that cannot be manufactured using traditional methods. Forged pipes are normally used for steam header and pressure vessel shell.
Extrusion Method for Seamless Pipe Manufacturing
In an extrusion method, 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 with help of extrusion process.
This is all about seamless pipe manufacturing process. Please do check another video to learn about welded pipe manufacturing process.
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