Stainless steel pipes are the most popular in the construction industry because of their strength and durability. Moreover, stainless steel pipes find application in different industries. The manufacturing process is comprised of two different methods, which give rise to the two main stainless steel pipe types, namely, seamless and welded pipes. For both of them, the first step is to cast the raw material into a moldable state. Seamless pipes come about when the steel cast is stretched and molded to form a smooth tube. Welded steel, on the other hand, is produced when the mold is shaped to tube and the edges welded together to form a pipe.
These stainless steel pipe types were both first produced in the 1800s and have since evolved into the more efficient processes that are used today. Because of its high demand, stainless steel pipes are produced in millions of tons annually.
Owing to their strength and versatility, steel pipes are used to transport liquids and gases in underground channels. In the construction of buildings, they are used to protect electrical connections from interference. These pipes can be made in different weights, and this means they can fit in a broader range of applications such as the manufacturing of bicycle frames, street light poles, flag-posts, refrigeration units, heating plants, and plumbing systems, among others.
The first use of pipes was during the agrarian revolution, where farmers used them to divert water from nearby sources to their farms. As early as 2000 B.C., tubes made from reeds were used in China to transport water from one location to another. In other places, the ancient people used clay pipes. The first modern pipes were manufactured in Europe and were made from lead, in the early century A.D. Other regions made their pipes using locally available materials such as bamboo and wood. The first water connection was made in America using hollow logs.
Welded steel was first manufactured in 1815 when William Murdock invented a coal-powered lighting system that he needed to install in the streets of London. To achieve this, he joined together unwanted gun muzzles and ended up with long pipes, which he used to convey the coal gas. They managed to light up the city, and this created a demand for the pipes. This brought about the need to look for more efficient ways of producing pipes.
From that time, different methods of manufacturing pipes were invented, with the latter being more efficient than the former. Manufacturing machines were designed along the way and technology was improved with time. Welded tubes were invented first because their manufacturing process was more straight forward. Seamless pipes followed later, and they were first made by boring a hole through concrete, metallic cylinder. The seamless pipes ended up having a higher demand and found application in many industries.
The manufacturing technology has been improving for both welded and seamless tubes to the current processes, which are more efficient and allow for bulk manufacturing.
The two types of stainless steel pipes, welded, and seamless, both have different applications in the market. Seamless pipes are thinner but stronger and are used in the automobile industry, and for conveying liquids. Welded pipes, on the other hand, have thick walls and better consistency, making them more suitable for plumbing works, transporting gas, covering electrical connections.
Pipes are made from recycled steel, which is combined with other relevant metals during the manufacturing process. Sulfuric acid is used as a cleaning agent in the process. The finished product is coated with oil to protect the pipe from corrosion.
Both the welded and seamless pipes are made from the same initial process. The first general step is smelting the scrap metal and adding other necessary compounds. It is then molded into the desired material and finally cut and packaged to meet the customer’s needs.
Here are the steps involved:
Ingot production: The scrap metal is passed through a furnace for smelting and removal of unwanted substances. The molten metal is then molded into blocks of metal called ingots.
Blooms and slabs: The ingots are passed through steel rollers to be squeezed into thinner sheets which can either be blooms or slabs depending on the process used.
Further processing: Blooms are rolled some more to make billets which will eventually be used to create seamless pipes. Slabs, on the other hand, are heated and passed through a mill to make thin pieces called skelp that will be used to produce welded pipes.
Skelp is passed through rollers and while at it, the edges curl into an unfinished pipe. The pipe is then welded and passed through a high-pressure roller to strengthen the joint. Square billets, on the other hand, are passed through a heating furnace then rolling mills which will stretch it, causing a hole to develop at the center. This is then refined by putting it through the rolling mills until the desired smoothness is achieved.