Steel pipes are long, hollow tubes that are used for a variety of purposes. They are produced by two distinct methods which result in either a welded or seamless pipe. In both methods, raw steel is first cast into a more workable starting form. It is then made into a pipe by stretching the steel out into a seamless tube or forcing the edges together and sealing them with a weld. The first methods for producing steel pipe were introduced in the early 1800s, and they have steadily evolved into the modern processes we use today. Each year, millions of tons of steel pipe are produced. Its versatility makes it the most often used product produced by the steel industry. Steel pipes are found in a variety of places. Since they are strong, they are used underground for transporting water and gas throughout cities and towns. They are also employed in construction to protect electrical wires. While steel pipes are strong, they can also be lightweight. This makes them perfect for use in bicycle frame manufacture. Other places they find utility is in automobiles, refrigeration units, heating and plumbing systems, flagpoles, street lamps, and medicine to name a few. People have used pipes for thousands of years. Perhaps the first use was by ancient agriculturalists that diverted water from streams and rivers into their fields. Archeological evidence suggests that the Chinese used reed pipe for transporting water to desired locations as early as 2000 B.C. (Francis, 2009)
Development of the modern day welded steel pipe can be traced back to the early 1800s. In 1815, William Murdock invented a coal burning lamp system. To fit the entire city of London with these lights, Murdock joined together the barrels from discarded muskets. He used this continuous pipeline to transport the coal gas. When his lighting system proved successful a greater demand was created for long metal tubes. To produce enough tubes to meet this demand, a variety of inventors set to work on developing new pipe making processes. An early notable method for producing metal tubes quickly and inexpensively was patented by James Russell in 1824. In his method, tubes were created by joining together opposite edges of a flat iron strip. The metal was first heated until it was malleable. Using a drop hammer, the edges folded together and welded. The pipe was finished by passing it through a groove and rolling mill. Russell’s method was not used long because in the next year, Comenius Whitehouse developed a better method for making metal tubes. This process, called the butt-weld process is the basis for our current pipe-making procedures. In his method, thin sheets of iron were heated and drawn through a cone-shaped opening. As the metal went through the opening, its edges curled up and created a pipe shape. The two ends were welded together to finish the pipe.
Welded pipe is formed by rolling steel strips through a series of grooved rollers that mold the material into a circular shape. Next, the unwedded pipe passes by welding electrodes. These devices seal the two ends of the pipe together. This process in the United States was opened in 1832 in Philadelphia. Gradually, improvements were made in the Whitehouse method. (Ellyn, 2009) One of the most important innovations was introduced by John Moon in 1911. He suggested the continuous process method in which a manufacturing plant could produce pipe in an unending stream. He built machinery for this specific purpose and many pipe manufacturing facilities adopted it. While the welded tube processes were being developed, a need for seamless metal pipes arouses. Seamless pipes are those which do not have a welded seam. They were first made by drilling a hole through the center of a solid cylinder. This method was developed during the late 1800s. These types of pipes were perfect for bicycle frames because they have thin walls, are lightweight but are strong. In 1895, the first plant to produce seamless tubes was built. As bicycle manufacturing gave way to auto manufacturing, seamless tubes were still needed for gasoline and oil lines. This demand was made even greater as larger oil deposits were found.
As early as 1840, ironworkers could already produce seamless tubes. In one method, a hole was drilled through a solid metal, round billet. The billet was then heated and drawn through a series of dies which elongated it to form a pipe. This method was inefficient because it was difficult to drill the hole in the center. This resulted in an uneven pipe with one side being thicker than the other. In 1888, an improved method was awarded a patent. In this process the solid billed was cast around a fireproof brick core. When it was cooled, the brick was removed leaving a hole in the middle. Since then new roller techniques have replaced these methods.
Pipe bending is a crucial component in the formation of many different types of pipelines, like the ones that are used to transport such products as oil, natural gas, water and even sewage. The most valuable of all these products is of course oil. Before the invention of pipe bending for oil pipelines, oil was transported from oil wells to railway stations by horse in converted wooden whiskey barrels. It is because of these wooden whiskey barrels that we still measure oil by the barrel today. Oil pipelines were first used in Pennsylvania to connect an oil field to a railway station. This first pipeline spanned 6 miles and was made entirely out of wrought iron. Eventually the idea caught on and improvements where made leading up to our modern pipelines which are now made out of metal. Although when one thinks of pipelines they may immediately jump to those that are used for oil, there are many other types of pipelines that are used for different reasons. Pipelines – are the ones that probably first come to mind when you think or an oil pipeline. These pipelines consist of very long pipes with large diameters and are used to transport products such as crude or refined oil and natural gas long distances. Transportation pipelines can stretch between cities, countries and even continents. (Helber, 2009)
Without pipelines our civilization would come to a screeching halt. There are two types of steel pipe, one is seamless and another has a single welded seam along its length. Both have different uses. Seamless tubes are typically more light weight, and have thinner walls. They are used for bicycles and transporting liquids. Seamed tubes are heavier and more rigid. The have a better consistency and are typically straighter. They are used for things such as gas transportation, electrical conduit and plumbing. Typically, they are used in instances when the pipe is not put under a high degree of stress. Certain pipe characteristics can be controlled during production. For example, the diameter of the pipe is often modified depending how it will be used. The diameter can range from tiny pipes used to make hypodermic needles, to large pipes used to transport gas throughout a city. The wall thickness of the pipe can also be controlled. Often the type of steel will also have an impact on pipe’s the strength and flexibility. Other controllable characteristics include length, coating material, and end finish.
Seamless pipe is manufactured using a process that heats and molds a solid billet into a cylindrical shape and then rolls it until it is stretched and hollowed. Since the hollowed center is irregularly shaped, a bullet-shaped piercer point is pushed through the middle of the billet as it is being rolled. Typically, a light amount of oil is applied to steel pipes at the end of the production line. This helps protect the pipe. While it is not actually a part of the finished product, sulfuric acid is used in one manufacturing step to clean the pipe. Steel pipes are made by two different processes. The overall production method for both processes involves three steps. First, raw steel is converted into a more workable form. Next, the pipe is formed on a continuous or semi continuous production line. Finally, the pipe is cut and modified to meet the customer’s needs.
Blooms are typically processed further before they are made into pipes. Blooms are converted into billets by putting them through more rolling devices which make them longer and narrower. The billets are cut by devices known as flying shears. These are a pair of synchronized shears that race along with the moving billet and cut it. This allows efficient cuts without stopping the manufacturing process. These billets are stacked and will eventually become seamless pipe. Slabs are also reworked. To make them malleable, they are first heated to 2,200° F (1,204° C). This causes an oxide coating to form on the surface of the slab. (Boycott, 2010)
This coating is broken off with a scale breaker and high pressure water spray. The slabs are then sent through a series of rollers on a hot mill and made into thin narrow strips of steel called scalp. This mill can be as long as a half mile. As the slabs pass through the rollers, they become thinner and longer. In the course of about three minutes a single slab can be converted from a 6 in (15.2 cm) thick piece of steel to a thin steel ribbon that can be a quarter mile long. After stretching, the steel is pickled. This process involves running it through a series of tanks that contain sulfuric acid to clean the metal. To finish, it is rinsed with cold and hot water, dried and then rolled up on large spools and packaged for transport to a pipe making facility. After either type of pipe is made, they may be put through a straightening machine. They may also be fitted with joints so two or more pieces of pipe can be connected. The most common type of joint for pipes with smaller diameters is threading—tight grooves that are cut into the end of the pipe. The pipes are also sent through a measuring machine. This information along with other quality control data is automatically stenciled on the pipe. The pipe is then sprayed with a light coating of protective oil. Most pipes are typically treated to prevent it from rusting. This is done by galvanizing it or giving it a coating of zinc.
Depending on the use of the pipe, other paints or coatings may be used. A variety of measures are taken to ensure that the finished steel pipe meets specifications. For example, x-ray gauges are used to regulate the thickness of the steel. The gauges work by utilizing two x rays. One ray is directed at a steel of known thickness. The other is directed at the passing steel on the production line. If there is any variance between the two rays, the gauge will automatically trigger a resizing of the rollers to compensate. Pipes are also inspected for defects at the end of the process. One method of testing a pipe is by using a special machine. This machine fills the pipe with water and then increases the pressure to see if it holds.
Defective pipes are returned for scrap. Without the advancement of metal fabrication many things we take for granted could not be made today. One of the most useful forms is the one used to bend pipes to create such things as water lines, natural gas pipes and oil pipelines. The first pipeline was made out of wrought iron and it spanned over 6 miles from an oil field in Titusville Pennsylvania to a railway station in Oil Creek. Colonel Edwin Drake is credited with drilling the first commercial oil well in 1859 that used this revolutionary pipeline. Soon after the pipeline business grew and the type of metal used for pipes improved from wrought iron to steel. Thermally insulated steel pipelines are extremely important for oil and gas industry. (Bao, 2010)
Steel pipelines, which lie buried for hundreds of years, has extraordinary properties including excellent stress crack resistance to natural gas and its contaminants, low permeation to methane and hydrogen, high HDB rating at 20°C, 60°C and 80°C, superior impact resistance, squeeze off, and dependable UV performance for outside storage. The insulation material is usually polyurethane foam (PU), which has high thermal efficiency and is mechanically strong. Small, medium and large diameter pipes are available and the high strength of steel also makes bending and forming more difficult. Generally, Electric Resistance Welded (E.R.W.) steel Pipe are used for oil and gas processing and transmission lines registered and assures consistent quality in its application. These oil and gas pipes are equally good in hot or wet applications such as river crossings and rough terrain. The use of steel provides standard for pipe suitable for use in conveying gas, water and oil in both the oil and natural gas industries. Small, medium and large diameter steel pipes are available however, the high strength of steel makes bending and forming more difficult. Generally, Electric Resistance Welded (E.R.W.) steel pipe are used for oil and gas processing and transmission lines registered which assures consistent quality in its application.
ERW pipes are equally good in hot or wet applications like river crossing and rough terrains. Perhaps the greatest challenge which faces any industry is the self-challenge emanating from the inside of such an industry, which makes it imperative to develop the technology of this industry. There is also another challenge which is not less important. It is the availability of new alternatives of a competition nature. The self-challenge and availability of alternatives are two questions which clearly came to light in the First Arab Conference on Tubes industry organized by the Arab Iron and Steel Union in the period 6 – 8 June 2005. Within the context of the self-challenge, usually imposed by the technological development which makes it inevitable to be responsive to the needs of the pipes consumers either in terms of improving the quality, reducing the costs or diversifying the areas of application, the world pipes manufacturing companies could prove their capability to find new creative designs meeting the requirements of using the tubular goods, either they are welded or unwedded pipes. The necessity to introduce new developments into the tubular goods has arisen with the increasing demand for using such pipes in the transcontinental operations of transporting oil and gas to remote places, because the steel pipes are considered the best means for the gas transportation.
This has strengthened the development of the pipes industry at the world level and increased their production with the increasing demand for them. The total world production of pipes in 2004 amounted to 78.45 million tons, i.e., up by 15 million tons over the production level of 2002 which amounted to 63.38 million tons, that is, by an annual growing rate of 8%, which exceeded the rates achieved in the parent steel industry despite what it has achieved of production increase as its production in 2004 had exceeded one billion tons of crude steel. However, the growth rate of this industry did not exceed 4% during the first years of this decade. (Earnpiel, 2010)