Seamless Pipe Cold Rolling
Seamless pipe cold rolling is a process of forming the pipe wall whereby the wall is positioned between two rollers and is then compressed and contracted. This process is used for making seamless pipe and is used in the manufacture of high-pressure vessels and valves. The finished seamless pipe can be used for various applications such as water supply, gas distribution and pressurization.
The entire process of cold rolling begins with a hot rolled pipe that has been heated to over 800°C in an oven. The hot roll is then placed between the two rollers and subsequently fed through the process. Each pass through the rollers reduces the external diameter of the pipe and increases its internal diameter. This process of compressing the pipe wall continues until the desired pipe wall size and thickness is reached.
The two rollers used in the process are usually constructed of specially-shaped steel materials. Generally they will have a conical shape with grooves cut into them. These grooves allow the pipe to be compressed and contracted within the conical-shaped sections of the roller. The grooves also serve to further compress the material, as the walls of the pipe are pushed inwards against the corners of the roller grooves.
The finished seamless pipe is usually cut and inspected to ensure that it meets the desired standards. The seamless pipe must have a uniform wall thickness, with no corrosion or other imperfections. A variety of techniques can be employed to inspect the finished pipe, including visual, ultrasonic and magnetic particle testing.
The main advantage of using cold rolling for the manufacture of pipe is its speed and efficiency. Cold rolling can be completed in a fraction of the time of other methods and can be used in a variety of applications. Additionally, seamless pipe produced through cold rolling will generally have a much higher strength and durability than pipe produced by other processes.
Despite the advantages, there are some disadvantages of cold rolling. Cold rolled pipes lack the precision of other pipe-manufacturing processes and they can deform, particularly at the edges. The walls may also become thinner near the edges where the roller grooves are placed. Furthermore, cold rolled pipe must be heated before installation, in order to regain its original strength and durability.
Overall, seamless pipe cold rolling is a fast, efficient and cost-effective process for manufacturing high-pressure vessels, valves and pipes. It is used in a variety of industries and has particularly proved its value in the manufacture of stainless steel and other corrosion-resistant alloys.
