Seamless Precision Steel Tube Din 2391

Seamless precision steel tube is widely used in various industries such as oil, petrochemical, automobile, shipbuilding, machinery and equipment manufacturing. The seamless precision steel tube is a type of seamless steel tube with some additional requirements on its surface which makes the product more precise and free from defects. A seamless tube is produced by passing a circular blank through one or multiple sets of rollers and reels into a finished pipe. A seamless tube has no visible welded seams. The seamless precision steel tubes are manufactured to have a smooth surface and straight sections with even wall thickness throughout its length. They can be made from different grades of carbon or alloy steels depending on the final application they will be used in and their strength requirement.

Standard for Seamless Precision Steel Tube in DIN 2391

DIN 2391 is a German standard which is published by the German Society for Metals. For the seamless precision steel tube, the standard is applicable to carbon and alloy steels. Carbon steels are steels whose steel composition is made with a mixture of iron and carbon and alloy steels are steels which has been added other elements such as silicon, manganese, nickel, chromium, molybdenum and vanadium. All the materials and dimensions mentioned in this article is based on the German standard DIN 2391. DIN 2391 standard is applicable for seamless precision steel tubes with a wall thickness of up to 6.35 mm and inside diameter of up to 862 mm. The standard also specifies requirements for surface finish, internal and external diameter and wall thickness tolerances.

Requirements for the seamless precision tubes in Din 2391

The requirements for the seamless precision steel tubes in Din 2391 can be broken down into two categories – surface finish and dimensions. The surface finish requirements include the following: The internal diameter and wall thickness tolerances can be seen in the following chart:

Types of seamless precision steel tube

The seamless precision steel tube in DIN 2391 can be classified into 3 types of grades.

SS 330 and SS 340 diameter seamless precision tubes

SS 330 and SS 340 diameter seamless precision tubes are made from the chemical composition of C 0.3%, Mn 0.3%, S 0.03%, Si 0.3%, Cr 0.2%, Ni 0.6%. The chemical composition makes the product more resistant to corrosion and gives it high ductility. The product has a high yield strength of 520 MPa and tensile strength of 630 MPa. The product is commonly used as a boiler feed water tube and a condensate return line inside a power generating plant.

SS 250 and SS 260 diameter seamless precision tubes

SS 250 and SS 260 diameter seamless precision tubes are made from the chemical composition of C 0.3%, Mn 0.3%, S 0.03%, Si 0.3%, Cr 0.2%, Ni 0.6%. The product has a yield strength of 400 MPa and tensile strength of 500 MPa. The product is commonly used as a pressure boiler feed water tube, condensate return line and a steam turbine feed water tube.

SS 210 and SS 220 diameter seamless precision tube

SS 210 and SS 220 diameter seamless precision tubes are made from the chemical composition of C 0.3%, Mn 0.3%, S 0.03%, Si 0.3%, Cr 0.2%, Ni 0.6%. The product has a yield strength of 350 MPa and tensile strength of 450 MPa. The product is commonly used as a water tube for pressure boiler feed water, a condensate return line, steam turbine feed water tube and a hot air furnace feed water tube.

Conclusion

The seamless precision steel tube in DIN 2391 is commonly used in various industries such as oil, petrochemical, automobile, shipbuilding, machinery and equipment manufacturing. The seamless precision steel tube is a type of seamless steel tube with some additional requirements on its surface which makes the product more precise and free from defects. A seamless tube is produced by passing a circular blank through one or multiple sets of rollers and reels into a finished pipe. A seamless tube has no visible welded seams. The seamless precision steel tubes are manufactured to have a smooth surface and straight sections with even wall thickness throughout its length. They can be made from different grades of carbon or alloy steels depending on the final application they will be used in and their strength requirement.