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In this article, we will have a brief look at some of the differences between seamless and ERW that can have a significant effect on your application and the economics of the system.

The manufacturing process for Electric Resistance Welding (ERW) pipe involves rolling metal and then welding it longitudinally across its entire length, resulting in an ERW pipe. The seamless pipe is manufactured by extruding the metal to the desired length, as compared to the ERW pipe, which is welded at the cross-section the entire length of its length, while the seamless pipe does not have any joints at the cross-section at all throughout its length.

The seamless pipe is manufactured from solid round billets, has no joints or welding and no welding process is involved in its manufacturing. In sizes from 1/8 inch to 26 inch outside diameter, the seamless pipes are finished according to the specifications of dimension and wall thickness. High-pressure applications such as hydrocarbon industries and the oil and gas industry can be served by this product Refineries, Oil & Gas Exploration & Drilling, Oil & Gas Transportation and Air and Hydraulic cylinders, Bearings, Boilers, Automobiles etc

A ERW pipe (Electric Resistance Welded) is a longitudinally welded pipe made from a strip or coil and can be produced up to a 24″ OD length. A cold-bent ribbon of steel is used to form a tube that is fused by a series of rollers, as implied by the name, as the method is to bend the ribbon through rollers. After the tube is formed, the tube is fused with electricity. The main use of this type of pump is to transport both water and oil at low to medium pressures. ERW Steel Pipe is available in a wide range of lengths from 2 3/8 inches in diameter to 24 inches in diameter, including lengths over 100 feet in length. The surfaces of the building can be finished in a variety of ways, including in bare or coated formats, and processing can be handled on site according to the customer’s requirements, depending on the specifications.

When it comes to manufacturing seamless and ERW pipes, what are the technologies that are used?

The production of seamless steel pipes and tubes up to seven inches OD is one of the most renowned technologies in the world today. This technology is referred to as “plug mill” and it is used for larger diameter pipes. Seamless Pipes and Tubes Manufacturing from 7-inches to 14-inches, is the most reliable technology when it comes to higher diameters. Our ERW Pipes & Tubes up to 21-inches OD are welded with high frequency induction welding technology.

How do seamless stainless steel pipes differ from ERW stainless steel pipes?

If it is ASTM A53, Type S means seamless, Type F means furnace but welded, and Type E indicates electrical resist welding. That’s it. As a matter of fact, there is a simple test that can be run to determine whether a pipe is seamless or ERW: the smoothness of the surface is the easiest way to identify whether it is seamless or ERW. Simply put, seamless is marketed on a myth that it has no flaws, but welded has this inherent flaw throughout the length of each tube. It is easy to understand why this concept is easily accepted by individuals that are unfamiliar with the products and are at the beginning of their learning process. Every product form and manufacturing method has its own set of inherent problems and potential defects for the product during manufacturing.

In order for consumers to become aware of these problems and defects, and how they may affect the application for which they are being used, they must become familiar with them. This will allow them to make a knowledgeable decision based on facts instead of relying on myths to make their decisions.

How does ERW pipe differ from seamless pipe in terms of its construction?

Steel Pipe and Steel Tube

Seamless pipes are constructed without a weld seam, as their name implies. In contrast, welded pipes have a longitudinal seam on the surface of their surface, which emanates from the welding process. Additionally to the method of construction a pipe can be made up of, the pressure capacity, the cost, and the individual application of the pipe will vary depending on the kind of pipe.

What is the cost difference between seamless and erw pipes?

In comparison to welded pipes, seamless pipes always have a higher cost because they require a longer manufacturing process plus more operations. Cold formed sheets are used in ERW pipes, which are then welded together by high frequency welding, which is a relatively simple process with a fraction of the cost of seamless pipes.

What are the advantages of seamless pipe over ERW pipe?

There are two factors that you need to keep in mind in order to make the most of the benefits associated with seamless pipes. There is no doubt that the working pressure capacity of a seamless pipe is 20% higher than the working pressure capacity of an ERW pipe, since seamless pipes are not susceptible to failure in the event that a higher pressure level is applied to them, as opposed to ERW pipes that could fail or burst at a higher pressure level. In addition, seamless pipes are not prone to intergranular corrosion, whereas welded pipes are. This is another popular reason to choose a seamless pipe over a welded pipe. However, even though welded pipes are seamless, the seams of welded pipes can develop visible lines at the grain boundary due to the sensitization process at the grain boundary. This can be seen at the grain boundary, especially in the heat affected zone or HAZ of the welded pipe. The ERW pipe becomes weaker as a result of intergranular corrosion.

What are the benefits of seamless pipes in the Oil & Gas sector?

There are various operations that require the use of seamless pipes including those that are highly pressurized. When it comes to the oil and gas industry, there is a strong force exerted on the pipes as a result of the circulation of medium through the system, especially when the temperature is high. This powerful force, when combined with the raising temperatures, is causing a high level of stress on pipes, which in turn makes the pressure increase. A seamless pipe is almost 20% more pressure-bearing than a seamless pipe, which makes them ideal for use in oil and gas applications since their pressure-bearing capacity is almost 20% higher.

The manufacturing process for seamless and welded pipes

There are many methods to produce ERW pipes, or electric resistance welded pipes, which can be made by cold-forming a sheet of steel into the shape of a cylinder or by some other process. Following the process of being cold formed, an electric current is then passed between the two edges of the steel as it is then hot formed. The electrical current used to heat the cold formed steel sheet causes it to be heated to a point where the edges are forced synchronically to form a bond when heated in this way. As a result of this welding process, a bond can be formed that does not require the use of welding filler in order for it to be successful. In order to achieve the best possible quality of weld, it is considered the most commercially viable option to use a high frequency ERW process in order to achieve the best possible result.

There is a longer and more intensive process involved in manufacturing Seamless pipes compared to welded pipes. In order to achieve the final product, the process uses heat as well as a number of other operations. During the first step of the production process, raw steel is heated and then molded into solid billets. This is done by bending the raw steel alloy into the shape of a cylinder using these solid billets. The raw steel pipe is then rolled to achieve a cylindrical shape, and then it is hollowed and stretched until it becomes a finished product with a stretched and hollowed shape. A new product that has been created has an irregularly shaped center, which makes it a unique product. While the billet is being rolled, a bullet-shaped piercer point is rammed through the center of the billet in order to create a uniform surface and uniform hollow. The piercer point is then used to form an even surface and uniform hollow. We are also erw tubing suppliers.

Stainless Steel Seamless Pipe or ERW Pipe?

A number of specifications are used to manufacture pipes. However, if the ASTM A53 specifications are used in the production of the pipes, then the pipes are marked through stencils. It is important to note that the pipes are manufactured according to several specifications. The stencil print on the pipe indicates that the pipe is seamless. The stencil print that indicates Type S indicates that it has an electrical resist welded construction. On the other hand, if Type E is stencilled, it indicates a seamless construction confirming welded pipes is by the use of a UV examination. There is a distinct difference in the grain structure of the pipe under ultraviolet light, which can be seen in the weld zone of the pipe. The fact remains that today there would not be any welds if there weren’t surface treatments to minimize the weld. There is also the possibility of detecting welds under a UV light.

1. Raw material

There are two types of tubes: seamless tubes are made out of round steel billets and ERW tubes are made out of hot rolled coils. Even though the raw materials used in the manufacturing process are quite different, it is important to note that the quality of the end product, tubes, entirely depends on both factors – the initial condition and quality of raw materials at the beginning of manufacturing and the control of quality during the manufacturing process.

2. Manufacturing process

The hollow shape is achieved by heating and pushing round steel billets over piercing rods until they become hollow, after which their length and thickness are controlled with extrusion techniques. In contrast, ERW tubes are produced entirely differently. They are bent in an axial direction and then welded throughout their length with electric resistance welding. The coils are then welded together along their entire length.

3. Welding process

The seamless tubes are made out of extruded metal, they are not welded in either axial or radial directions, whereas ERW tubes are manufactured by bending coils along their central axis, and therefore they are welded throughout their length, as opposed to seamless tubes.

4. Size

In contrast, even the most advanced Steel Company using ERW technologies, is only able to assemble stainless steel tubes up to 24 inches of outside diameter on their assembly line, whereas the seamless stainless steel tubes have a completely finished finish on their assembly line that can be manufactured up to 26 inches of outside diameter.

5. Applications

There are generally two types of tubes: seamless tubes and ERW tubes. Seamless tubes are used for applications that require high pressures, and ERW tubes are used for applications that require low to medium pressures.

Furthermore, seamless tubes are widely used in applications related to oil and gas, refineries, and other chemical industries because of the inherent safety features they have. In these industries, zero leakage policies must be implemented in order to ensure the safety of the workers and plants. In spite of this, well-made ERW tubes that are subjected to strict quality control can also be used to perform similar services such as water transport, scaffolding, and fencing in addition to the routine ones.

6. Finish

There is no doubt that the internal surface of ERW tubes can be controlled through good quality control techniques, and thus they are always superior to seamless tubes in terms of their internal surface.

Mokshi Shah
Mokshi Shah