Design and the manufacturing process of steel pipes

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.

 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 semicontinuous production line. Finally, the pipe is cut and modified to meet the customer’s needs.

Ingot production

  • 1 Molten steel is made by melting iron ore and coke (a carbon-rich substance that results when coal is heated in the absence of air) in a furnace, then removing most of the carbon by blasting oxygen into the liquid. The molten steel is then poured into large, thick-walled iron molds, where it cools into ingots.
  • 2 In order to form flat products such as plates and sheets, or long products such as bars and rods, ingots are shaped between large rollers under enormous pressure.

Producing blooms and slabs

  • 3 To produce a bloom, the ingot is passed through a pair of grooved steel rollers that are stacked. These types of rollers are called “two-high mills.” In some cases, three rollers are used. The rollers are mounted so that their grooves coincide, and they move in opposite directions. This action causes the steel to be squeezed and stretched into thinner, longer pieces. When the rollers are reversed by the human operator, the steel is pulled back through making it thinner and longer. This process is repeated until the steel achieves the desired shape. During this process, machines called manipulators flip the steel so that each side is processed evenly.
  • 4 Ingots may also be rolled into slabs in a process that is similar to the bloom making process. The steel is passed through a pair of stacked rollers which stretch it. However, there are also rollers mounted on the side to control the width of the slabs. When the steel acquires the desired shape, the uneven ends are cut off and the slabs or blooms are cut into shorter pieces.

Further processing

  • 5 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 more narrow. 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.
  • 6 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. 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 skelp. 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.
  • 7 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.

Pipe making

  • 8 Both skelp and billets are used to make pipes. Skelp is made into welded pipe. It is first placed on an unwinding machine. As the spool of steel is unwound, it is heated. The steel is then passed through a series of grooved rollers. As it passes by, the rollers cause the edges of the skelp to curl together. This forms an unwelded pipe.
  • 9 The steel next passes by welding electrodes. These devices seal the two ends of the pipe together. The welded seam is then passed through a high pressure roller which helps create a tight weld. The pipe is then cut to a desired length and stacked for further processing. Welded steel pipe is a continuous process and depending on the size of the pipe, it can be made as fast as 1,100 ft (335.3 m) per minute.
  • 10 When seamless pipe is needed, square billets are used for production. They are heated and molded to form a cylinder shape, also called a round. The round is then put in a furnace where it is heated white-hot. The heated round is then rolled with great pressure. This high pressure rolling causes the billet to stretch out and a hole to form in the center. Since this hole is irregularly shaped, a bullet shaped piercer point is pushed through the middle of the billet as it is being rolled. After the piercing stage, the pipe may still be of irregular thickness and shape. To correct this it is passed through another series of rolling mills.

Final processing

  • 11 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 pipe is 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.
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Solutions that increase profitability in the piping systems

It’s the inside that counts!

That’s what one considers nowadays when the Pipe technology being discussed! They call it the FlowMax TP system! Because of the thermoplastic pipe coating the inside surface is slippery, i.e. friction is reduced and flow resistance is the lowest possible. Meaning you save up to 50% in energy consumption. You can choose a pipe of smaller diameter but keep the same pump capacity. You can select a smaller pump and in larger systems you can reduce the  number of pumps and The result will be lower investment costs and lower running costs. The second solution is slimmer inner wall. Thinner walls give a larger inner diameter. Because of the high quality steel and the spiral welding technique, the pipes are lightweight and strong. This means that we can use a thinner steel coil, which in turn gives you a pipe that has a larger inner diameter for the same outer diameter. Or you can keep a specified flow but reduce the outer dimension. Whichever you choose, the weight of the system is reduced. 


The complete FlowMax pipe system contains everything needed for all types of installations – pipes, couplings, valves, bends, T-pipes, adapters, threaded outlets, etc.

This should be kept in mind, galvanized pipes and galvanized pipe fittings is the most sustainable pipes and fittings in this industry. Now that you know this, everything will be easier and cheaper! ;)





Finding the right tube to the right blogs!

The piping industry has been one of the most important pillars of the industrial revolution. For as we know, there are tubes that connect everything together. The importance of this becomes more obvious when even in the saying pipe is used as the link to the most mundane! As an example, I can mention mouthpiece or why not YouTube! This YouTube is now the most common phrase that people use without perhaps knowing that it is a tube they’re talking about! Now that we know how important tubes are, we can concentrate on the blogs that I have come to call for pipes to information. Blogs about the pipe and fittings are not so common! But I found some that I want to introduce to you! The first is called Buchhausaltenessen and is in German! We all know that the Germans are good at everything, and tubes is no exception either! Therefore, I mention even a few blogs that are also in German. Frische Luft Berlin and Metaltimes is two more blogs dealing with this topic. But I have come across a couple of blogs that are in English and have much to offer! It is also within the pipe industry. I refer to just one of them, it’s called SCFB and gives you detailed information about a company that leads the Swedish tube industry. The company’s Alvenius. On subsequent occasions, I will give you additional tips, so keep an eye on this very blog!


Pipe & Piping industry

This is what pipe is according to Wikipedia:

A pipe is a tubular section or hollow cylinder, usually but not necessarily of circular cross-section, used mainly to convey substances which can flow — liquids and gases (fluids), slurries, powders, masses of small solids. It can also be used for structural applications; hollow pipe is far stiffer per unit weight than solid members.

In common usage the words pipe and tube are usually interchangeable, but in industry and engineering, the terms are uniquely defined. Depending on the applicable standard to which it is manufactured, pipe is generally specified by a nominal diameter with a constant outside diameter (OD) and a schedule that defines the thickness. Tube is most often specified by the OD and wall thickness, but may be specified by any two of OD, inside diameter (ID), and wall thickness. Pipe is generally manufactured to one of several international and national industrial standards.[1] While similar standards exist for specific industry application tubing, tube is often made to custom sizes and a broader range of diameters and tolerances. Many industrial and government standards exist for the production of pipe and tubing. The term “tube” is also commonly applied to non-cylindrical sections, i.e., square or rectangular tubing. In general, “pipe” is the more common term in most of the world, whereas “tube” is more widely used in the United States.

Both “pipe” and “tube” imply a level of rigidity and permanence, whereas a hose (or hosepipe) is usually portable and flexible. Pipe assemblies are almost always constructed with the use of fittings such as elbows, tees, and so on, while tube may be formed or bent into custom configurations. For materials that are inflexible, cannot be formed, or where construction is governed by codes or standards, tube assemblies are also constructed with the use of tube fittings.


Millions of piping miles since 1951

Alvenius was founded in 1951 and has focussed ever since on providing the industrial world with high-quality quick-connecting steel pipe systems. Today, Alvenius concentrates its expertise on Tunneling and Mining, Industry, Fire Protection, Snowmaking and Special Applications.

There have been miles and miles of piping delivered over the years!Swedish steel is the basis of Alvenius’ success, and FlowMax pipes are spiral-welded from pressure-vessel-class high-strength steel. This means that the pipes can be made with a thin yet strong wall and, due to the spiral welding, remain straight.  The benefits are many – low weight and a larger inner diameter for a given outer diameter and working pressure.
Strong finances, strong and far-sighted ownership and a clear vision about the direction of development mean that you can count on Alvenius and the availability of our skills and solutions long into the future.

We operate everywhere

You can find us in Asia, Africa, South America, Europe
and of course our home market of Sweden.
This international presence has many advantages. Above all it means that we have developed  a deep understanding of what’s needed to deliver superiour solutions and cost effective piping systems all over the world.


Renovating our summerhouse

We have started a big project – renovating our summerhouse – I know, it’s a little bit late in the summer but we really needed it. We are replacing the floors, and the whole bathroom and kitchen. That means that it’s going to run around a lot of construction workers and plumbers all day long. Luckily we don’t need to be there, we have already enjoyed our time in the country this summer, and we can still only go out on the weekends so it does not interfere our everyday life.

We ordered our piping system from our local store, and they are from Alvenius who appearantly makes the best piping systems in the world – so happy to get theese.

It’s not the first time we renovate; yet how many changes a renovation results in still fascinate me. One thinks that it should be enough to only replace a few things, like fixing the drain a little, but no, we have to replace the entire piping system and add the latest kinds of steel pipe that is custom made for the one or an other. I am not skeptical, I fully trust our workers – they have always done a great job for us. But I never stop being surprised by how big the project always gets. Luckily I have a lot of patience and also, we are smart to renovate at a time when we’re not in a hurry and have important deadlines. Many of our friends tend to start working and building things in the spring and always become disappointed and angry when it is not ready in time for midsummer.

We have learned that it always takes a lot longer than you think. You have to be realistic and have an open dialogue with the construction workers and plumbers. I’ll rather have it done after the summer so it’s ready for next year, than sit half the summer with construction workers in the neck.