DIN steel pipes

DIN/EN Steel pipes

DIN/EN steel pipes refer to steel pipes that adhere to the standards set by the Deutsches Institut für Normung (DIN) and European Norm (EN).

DIN represents German interests in international organizations such as CEN, the European standards body, and ISO, the International Standards Organization. Today, roughly 85 % of all national standards projects are European or international in origin.

DIN/EN steel pipes are used in various applications across industries such as construction, oil and gas, automotive, and manufacturing. They are suitable for conveying fluids, gases, and solids, as well as for structural purposes. DIN/EN standards specify the dimensions and tolerances for steel pipes. These include parameters such as outer diameter, wall thickness, length, and straightness. Compliance with these standards ensures uniformity and interchangeability of steel pipes.

Our products for DIN/EN Standard has been listed as follows:

European Standards for steel

With so many European  Standards specifying steel and steel products and replacing national standards, it is necessary to have a European designation system for steel.

Such a system is well established and implemented in almost all the European Standards. European Standards for steel products are the responsibility of the European Committee for Iron and Steel Standardization.

ECISS has the task of developing European Standards for the definition, classification, testing, analysis and technical delivery requirements for the products of the iron and steel industry and the implementation of these as national standards by members in order to achieve technical harmonization within the European Union. ECISS is an Associated Standards Body within the framework of the European Committee of Standardization.

European Standards published in the UK have the status of a British Standard and are characterized by the prefix ‘BS EN’ to their reference number. Other national standards bodies of Member States of the European Union publish identical European Standards with their appropriate prefixes, e.g. in Germany, ‘DIN EN’, in France ‘NF EN’, in Sweden ‘SIS EN’ etc. European Standards are essentially voluntary instruments except for certain situations, e.g. Public Procurement Directives, Construction Products Directive. According to the CEN rules, members in the UK, that is BSI, are obliged to announce the availability of European Standards and publish the identical text and to withdraw any conflicting national standards.

BS3059 II 360

BS 3059-2:1990 requirements for tubes not exceeding 127 mm outside diameter and 12.5 mm thickness. Depending on the operating temperature, it can be divided into two kinds general boiler pipes and high-pressure boiler pipes.

BS3059-II 440

BS 3059 PART 2-78 is the standard specifies the steel boiler and superheter tubes carbonn alloy and specified elevated temperature prop.

EN10216-1

P235GH is a European specified steel for use in pressure vessels, boilers and heat exchangers. The composition of this steel makes it ideal for applications where elevated working temperatures are the norm and the material is used by fabricators throughout the oil, gas and petrochemical industry.

Seamless steel tubes for pressure purposes

  • EN 10216-1    Non-alloy steel tubes with specified room temperature properties
  • EN 10216-2    Non alloy and alloy steel tubes with specified elevated temperature properties
  • EN 10216-3    Alloy fine grain steel tubes
  • EN 10216-4    Non-alloy and alloy steel tubes with specified low temperature properties
  • EN 10216-5    Stainless steel tubes

Material

  • z.Bsp: P235GH TC1, P235GH TC2, 16Mo3

DIN 17175

DIN 17175 steel pipes are used in boiler installations, high-pressure pipelines and tank construction and special machinery for both high (градусов 600) temperature and high-pressure devices. This alloy steel pipe is just a big class,and it has many classifivations.

EN 10028 – P265GH

P265GH is a weldable pressure vessel and boiler steel grade used by the world’s industrial fabricators. The material, which is ideally suited for elevated temperature service, is commonly found in the oil & gas, petrochemical and chemical industry.

DIN 2391

DIN 2391 standard specifies the Seamless steel tubes used forMechanical and Automobile.

BSP British Standard Pipe

The British Standard Pipe (BSP) is a family of standard screw thread types that has been adopted internationally for interconnecting and sealing pipe ends by mating an external (male) with an internal (female) thread.

BS3059 Part I, BS3059-I 320 CFS

BS 3059 standard accord to the steel boiler and superheater tubes. Part I-87 low tensile carbon steel tube without specified elevated temperature preperites.

DIN 2440

The DIN 2440 standard applies to medium-weight tubes suitable for screwing used in applications of medium pressure air and non-hazardous gases. The most common material is St33.2(also known as S185) conforming to DIN 17100. DIN 2440 steel pipes are often supplied in seamless type with zinc coating.


Old and new DIN Designations

Over the years, many DIN standards were integrated into the ISO standards, and thus also a part of the EN standards. In the cource of the revision of the European standards serveral DIN standards were withdrawn and replaced by DIN ISO EN and DIN EN.

The standards used in the past such as the DIN 17121, DIN 1629, DIN 2448 and the DIN 17175 have since been mostly replaced by Euronorms. The Euronorms clearly distinguish the pipe's area of application. Consequently different standards now exist for pipes used as construction materials, pipelines or for mechanical engineering applications.

This distinction was not as clear in the past. For example, the old St.52.0 quality was derived from the DIN 1629 standard which was intended for pipeline systems and mechanical engineering applications. This quality was also often used for steel structures, however.

The info below explains the main standards and steel qualities under the new system of standards.

Seamless Pipes and Tubes for Pressure Applications

The EN 10216 Euronorm replaces the old DIN 17175 and 1629 standards. This standard is designed for pipes used in pressure applications, such as a pipeline. This is why the associated steel qualities are designated by the letter P for 'Pressure'. The value that follows this letter designates the minimum yield strength. The subsequent letter designations provide additional information.

The EN 10216 comprises several parts. The parts that are relevant to us are as follows:

Some examples:

  1. EN 10216-1, Quality P235TR2 (formerly DIN 1629, St.37.0)
    P = Pressure
    235 = minimum yield strength in N/mm2
    TR2 = quality with specified properties relating to aluminum content, impact values and inspection and test requirements. (In contrast to TR1, for which this is not specified).
  2. EN 10216-2, Quality P235 GH (formerly DIN 17175, St.35.8 Cl. 1, boiler pipe)
    P = Pressure
    235 = minimum yield strength in N/mm2
    GH = tested properties at higher temperatures
  3. EN 10216-3, Quality P355 N (more or less equivalent to DIN 1629, St.52.0) P = Pressure
    355 = minimum yield strength in N/mm2
    N = normalized*

* Normalized is defined as: normalized (warm) rolled or standard annealing (at a min temperature of 930°C). This applies to allqualities designated by the letter 'N' in the new Euro Standards.

Pipes: the following standards are replaced by DIN EN

Old standard

Execution Norm Steel grade
Welded DIN 1626 St.37.0
Welded DIN 1626 St.52.2
Seamless DIN 1629 St.37.0
Seamless DIN 1629 St.52.2
Seamless DIN 17175 St.35.8/1
Seamless ASTM A106* Grade B
Seamless ASTM A333* Grade 6

New standard

Execution Norm Steel grade
Welded DIN EN 10217-1 P235TR2
Welded DIN EN 10217-3 P355N
Seamless DIN EN 10216-1 P235TR2
Seamless DIN EN 10216-3 P355N
Seamless DIN EN 10216-2 P235GH
Seamless DIN EN 10216-2 P265GH
Seamless DIN EN 10216-4 P265NL

* ASTM standards will remain valid and will not be replaced by Euronorms in the near future


DIN/ EN/ ISO DIFFERENCES

Gain an insight into the difference between DIN, EN and ISO standards!

Here you can find information on what changes have been made to the respective product standard and what differences between the DIN, EN and ISO standards this has caused. Get an overview and use the clear direct comparison of the withdrawn DIN standards and the current EN and ISO standards.

In the past, standardisation work in Germany was carried out on a national level by Deutsches Institut für Normung e. V. (DIN). On a European level there are also EN standards, as well as ISO standards on an international level, which are issued by the International Organization for Standardization.

DIN, ISO, EN

The differences

DIN

National standards (DIN) are largely being replaced by international and European standards. DIN standards are now only issued for products that have no ISO or EN standards

ISO

In accordance with the task and objective of the ISO, which was founded in 1946, international standards (ISO) are intended to standardise technical rules worldwide, thus simplifying the exchange of goods and removing trade barriers.

EN

The purpose of European standards (EN) is to harmonise technical rules and laws within the single European market that was jointly established on 01/01/1993. As far as possible, existing ISO standards must generally be adopted as EN standards in unaltered form. The difference between ISO and EN standards is that, following the decision of the European Council, EN standards must be adopted and implemented immediately and without any changes as national standards in the member states, and, at the same time, the corresponding national standards must be withdrawn.

Process of seamless pipe

Cold drawn seamless steel tube deformed process

Cold Drawn Seamless Mechanical Tubing (CDS) is a cold drawn 1018/1026 steel tube which offers uniform tolerances, enhanced machinability and increased strength and tolerances compared to hot-rolled products.

Cold drawn seamless steel tube deformed process

Cold drawn steel tube is with hot-rolled steel coil as raw material, and tandem cold rolling pickled to remove oxide scale, its finished rolling hard roll, rolling hard volumes due to the continuous cold deformation caused by cold hardening strength, hardness increased indicators declined tough plastic, stamping performance will deteriorate, which can only be used for simple deformation of the parts.

Rolling hard roll can be used as the raw material of the hot-dip galvanizing plant, hot dip galvanizing line set annealing line. Rolling hard roll weight is generally 6 to 13.5 tons, the coil diameter of 610mm.

Hot rolled seamless steel pipe deformed process

Hot-rolled seamless steel pipe production base deformation process can be summarized as three stages: perforation, extension and finishing.

Hot rolled seamless steel pipe deformed process

The main purpose of the perforation process is to become a solid round billet piercing hollow shell. Capillary in the specifications, accuracy and surface quality can not meet the requirements of the finished product, further improvements are needed to deform the metal through. The main purpose of the stretching machine is further reduced sectional view (main compression wall) for a larger axial extension, so that the capillary improved dimensional accuracy, surface quality and organizational performance.

After stretching machine rolled steel pipe shortage collectively need further molding mill in order to achieve the requirements of the finished pipe. Rolled steel due to pass in the method widely used in the production of seamless steel tubes.

So far, due to the method pass rolling steel can be divided into two categories: core pension without rolling rolling (hollow body rolling), and with the mandrel. Sizing machines, reducing mill and stretch reducing mill belonging to the hole without mandrel type continuous rolling mills are generally coffin. Its main purpose is to reduce the diameter of the deformation process or sizing get finished steel, the wall thickness of process control, can make thinning, thickening or nearly unchanged.

All the traditional hole-type rolling machine with mandrel belong to extend machine. The main purpose is to reduce the deformation process perforated capillary wall thickness and outer diameter roll passes in the deformation zone and the mandrel posed, for a larger axial extension. At the same time a certain improvement in the organization, performance, accuracy, surface quality.

The main manufacturing technology of seamless carbon steel pipe

1.Plug rolling production

The production equipment consists of punching machine, automatic pipe rolling machine, coiling machine, sizing machine and reducing machine. The round tube is inserted into the hollow of the thick-walled tube, and the axes of the two rollers form an oblique angle with the rolling line. In recent years, the inclination angle has increased from 6° to 12° to 13° to 17°, increasing the speed of the punch. When producing structural seamless pipe with a diameter greater than 250mm, secondary perforation is used to reduce the thickness of the hollow billet wall. New technologies have also been developed to enhance the perforation process and improve the quality of the capillary.

2. Continuous rolling production

The production equipment includes punching machine, continuous rolling mill, and tension reduction machine. The round billet is pierced into a hollow billet, then inserted into the mandrel, and continuously rolled by 7 to 9 two-roll mills. After rolling, the mandrel bar is taken out and reheated to reduce tension. In 2014, the annual output of 140mm continuous rolling mills is 0.4 to 600,000 tons, which is 2 to 4 times that of plug mills. The characteristics of this unit are suitable for the production of steel pipes with a diameter of 168mm or less. However, the equipment investment is large, the installed capacity is large, and the processing and manufacturing are complex.

3. Three-roll rolling production

Three-roll rolling production is mainly used to produce thick-walled seamless steel pipes with high dimensional accuracy. The wall thickness accuracy of the seamless steel pipe produced by this manufacturing process can reach plus or minus 5%, and the pipe accuracy is twice that of the seamless steel pipe produced by other methods. This manufacturing technique developed rapidly with the invention of the new three-high skew rolling mill in the 1960s. The new type of rolling mill is characterized by rapidly rotating the inlet rotary rack to change the expansion angle of the tail, thereby preventing the triangle from appearing at the tail, and expanding the ratio of the outer diameter to the wall thickness of the production varieties from 12 to 35, which can not only produce thin-walled seamless welded steel pipes , but also can improve production capacity.

4. Extrusion tube production

The peeled round base is first perforated or expanded, then heated by induction heating or a salt bath, coated with lubricant, and loaded into the extruder. The metal is squeezed into the pipe through the circular gap between the mandrel and the tip of the pen. This manufacturing process is mainly used for the production of superalloy tubes, specialty tubes, composite tubes and non-ferrous metal tubes. It has a wide range of production but low volumes. The production of extruded tubes has also grown in recent years due to improvements in die materials, lubricants and extrusion speeds.

5. Cold rolling (cold drawing) production

This manufacturing process is used to produce small-diameter precision-shaped thin-walled low-carbon steel pipes. It is characterized by the use of multi-stage cycle manufacturing technology. In the 1960s, it began to develop in the direction of high speed, multi-line, long stroke and long tube blank. In addition, small roller mills have also been developed, mainly for the production of precision tubes with a thickness of less than 1mm. The cold rolling equipment is complex, the tool processing is difficult, and the specification conversion is not flexible. And usually a combined process of cold rolling and cold drawing is used, that is, cold rolling is used to reduce the wall thickness to obtain larger deformation, and cold drawing technology is used to obtain various specifications.

Cut to Length

Before cutting pipe and tubing

No matter the material, measure the diameter of the pipe or tube to be cut to ensure that you use the right-size tube cutter for the job. When determining how to make a straight cut, use a tape measure and a pencil or other writing instrument to mark on the surface where you want to cut. If possible, mark around the circumference of a pipe, especially when cutting with a handsaw. Ensure that a cut is as straight as possible by securing the pipe with a vise, clamp, miter box or even duct tape to keep the length from shifting out of place while cutting.

After cutting pipe and tubing

  • Unless a cut is perfectly clean, you should expect to remove burrs from around the edge, especially after sawing.
  • Use a deburring tool to clean the edge after tube cutting.
  • You may opt to use a metal file on the cut of a metal pipe.
Cut to length

What is a seamless pipe used for?

Seamless steel pipe is regularly used in the transportation of fluids such as water, natural gas, waste and air. It is also regularly required in many high-pressure, high-corrosive environments such as in the oil & gas, power generation and pharmaceutical industries. Some common uses of seamless pipes include:

Alloying Elements

Commonly used alloying elements and their effects are listed in the table given below.

Alloying Elements Effect on the Properties
Chromium Increases Resistance to corrosion   and oxidation. Increases hardenability and wear resistance. Increases high   temperature strength.
Nickel Increases hardenability. Improves   toughness. Increases impact strength at low temperatures.
Molybdenum Increases hardenability, high   temperature hardness, and wear resistance. Enhances the effects of other   alloying elements. Eliminate temper brittleness in steels. Increases high   temperature strength.
Manganese Increases hardenability. Combines   with sulfur to reduce its adverse effects.
Vanadium Increases hardenability, high   temperature hardness, and wear resistance. Improves fatigue resistance.
Titanium Strongest carbide former. Added to   stainless steel to prevent precipitation of chromium carbide.
Silicon Removes oxygen in steel making.   Improves toughness. Increases hardness ability
Boron Increases hardenability. Produces   fine grain size.
Aluminum Forms nitride in nitriding steels.   Produces fine grain size in casting. Removes oxygen in steel melting.
Cobalt Increases heat and wear   resistance.
Tungsten Increases hardness at elevated   temperatures. Refines grain size.

【H】 Ceramic lined pipe

Ceramic lined pipe is made through self-propagating high-temperature synthesis (SHS) technique.

【H】 Cast basalt lined steel pipe

Cast basalt lined steel pipe is composed by lined with cast basalt pipe, outside steel pipe and cement mortar filling between the two layers.

【H】 Ceramic Tile Lined Pipes

Ceramic tile lined pipes have very uniform coating of specially formulated ceramic material that is affixed to the inner of the pipe.

【H】 Rare earth alloy wear-resistant pipe

The material of the rare earth alloy wear-resistant pipe is ZG40CrMnMoNiSiRe, which is also the grade of rare earth alloy steel.

【H】 Tubes Erosion Shields

Tubes Erosion Shields are used to protect boiler tubing from the highly erosive effects of high temperatures and pressures thereby greatly extending tube life.

【H】 ASTM A213 T91 Alloy Tube

The ASTM A213 T91 seamless tubes are primarily used for boiler, superheater, and heat-exchanger.