Manufacturing and application of seamless steel pipe

Seamless tubes are tubes without seams or welds. Seamless steel tubes are considered to be able to withstand higher pressures, higher temperatures, higher mechanical stress and corrosive atmospheres.

1. Manufacturing

Seamless steel tubes are manufactured using a number of different methods. The method used depends on the desired diameter, or ratio of diameter to wall thickness, required for the desired application.

Generally, seamless steel tubes are made by first casting raw steel into a more workable form—a hot solid billet. It is then “stretched” and pushed or pulled onto the forming die. This results in hollow tubes. The hollow tube is then “extruded” and forced through a die and mandrel to obtain the desired inner and outer wall diameters.

In order to ensure that the seamless steel tube meets certain standards, it must be subjected to specific heat treatment to ensure that its metallurgical properties meet the necessary requirements. When required, special piping materials are only available from duplex and super duplex seamless pipes from NORSOK M650 approved manufacturers. This ensures extremely high quality and durability for our customers.

2. Application

Seamless steel tubes are versatile and thus can be found in a wide range of fields. This includes the oil and gas, refinery, petrochemical, chemical, fertilizer, power and automotive industries.

Seamless steel tube is commonly used to transport fluids such as water, natural gas, waste and air. It is also frequently required in many high pressure, highly corrosive environments as well as bearing, mechanical and structural environments.

3. Advantages

Strength: Seamless steel tube has no seams. This means that the possibility of “weak” seams is eliminated, so seamless steel tube can typically withstand 20% higher working pressures than welded pipe of the same material grade and size. Strength is probably the biggest benefit of using seamless steel tube.

Resistance: The ability to withstand higher resistance is another benefit of being seamless. This is because the absence of seams means that impurities and defects are less likely to appear as they more naturally occur along the weld.