Seamless steel tube is different from welded steel tube？

The difference between the seamless steel tube and welded steel pipe, i believe most people still don't know, today is to popularize it.
Seamless steel tube
In appearance, seamless steel tube is different from welded tube in that welded steel tube has welded ribs inside the cavity.
Seamless steel tube has a high working pressure. Welded steel tubes are usually about 10. MPa, now welded steel pipe has done a seamless splicing solution.
Seamless steel tube is formed in one step in cold rolling. Welded pipes must be electrically welded after production, usually including spiral welding and direct welding. Most small diameter welded pipe adopts straight seam welding, while large diameter welded pipe adopts spiral welding. The welding method of spiral welded pipe is the same as that of straight welded pipe, but the straight welded pipe will inevitably have a lot of T-welding, so the probability of missing welding is greatly increased. Moreover, the welded metal at the T-weld is often in a state of three-way deformation, which increases the possibility of cracks. Seamless steel tube has better features and is naturally more expensive.
Spiral welded pipe
Spiral welded pipe is used as a pipeline for the transportation of fluid mechanics, such as crude oil, natural gas, water, liquefied gas, steam, bending, torsional strength and compressive strength at the same time, light net weight, so it is also widely used in the manufacture of mechanical parts and engineering structures. It is also commonly used in the manufacture of various strategic weapons, barrel rifling, bullets, etc.
The key is that the molding process is different. Common steel pipes, such as drinking water pipes, are generally welded with a bent sheet metal plate. Spiral welded pipe is generally based on the circular double seam inventory will be melted liquid iron backlog, and then through stretching and other processes for molding, so that it will not be welded. In the characteristics, especially in the ability to work under pressure, compared with ordinary steel pipe has been greatly improved, so it is often used in high pressure mechanical equipment. Such as hydraulic mechanical equipment pipeline connection. The welding position of ordinary steel pipe is generally weak.