Decision on Whether Using Seamless or Welded Pipe

The wall thickness or diameter ratio and the specified pipe tolerances are the two mainly factors influence people choose in using seamless pipes or welded pipes. Next we will introduce some factors which influence whether using seamless or welded Pipe. Availability is the first factor which can influence people whether using seamless or welded steel pipe. Therefore, from wide material in stock we may only provide a limited number of alloys when manufacture the seamless hot rolled pipes. We may not use the steel plates or coils for they are shortage. These plates or coils are mainly used to produce welded pipes with numbers of different material grades. We can recover from special alloys and service stores with the small quantities of raw materials. Alloy C4 is also a kind of service stores or special alloys and we can cut them and get them from wide material which is in stock. This is the first factor which can influence people whether using seamless or welded pipe.

Tolerances are the second factor which can influence people whether using seamless or welded pipe. The hot rolled seamless pipes have f 12.5 percent of wall thickness tolerance. In ASTM A999 or EN ISO 1127 T2, the hot rolled seamless pipes are fundamentally specified. However, the manufacturing procedure can cause differences in thickness of the wall. We can use the wall thickness differences to lead a possible eccentricity. In the other word, we can use the wall thickness differences to form a deviation which is from symmetry. The tolerance of welded pipes wall thicknesses usually is ASTM A999 to EN ISO 1127 T3. In order to make sure that the wall thickness tolerance are very constant when pass through the entire mild steel pipe body and make sure that the wall thickness tolerance are the best tolerance, we should take the evenness of the coil thickness or the steel plate into consideration. They are the second factor which can influence people whether using seamless or welded pipe.

Pipe lengths and quantities are factors which can influence people whether using seamless or welded steel pipe. We may produce the length of seamless pipes relying on the weight a meter or a rod. From this, we can know that the lengths of pipe would maximum 13 meters when the lengths of pipe up to NB 100. While the lengths of pipe would maximum 4 meters when they are up to NB 200. Then we can produce the lengths of pipe with maximum 4 meters. Coil is the main material to make the minimum production. Those are factors which can influence people whether using seamless or welded pipe.