Difference between seamless steel pipe and welded steel pipe

Steel pipe is a kind of hollow long steel, which is widely used as the pipeline for conveying fluid, such as oil, natural gas, water, gas, steam, etc. According to the production process, it can be divided into seamless steel pipe and welded steel pipe. What’s the difference between the two kinds?

ASTM A53 Grade B seamless steel pipes

ASTM A53 Grade B seamless steel pipes

1. Different materials

Welded steel pipe: the welded steel pipe refers to the steel pipe with a joint on the surface which is welded after the steel strip or steel plate is bent and deformed into a circular, square and equal shape. The blank used for welding the steel pipe is steel plate or steel strip.

Seamless steel pipe: a steel pipe made of a whole piece of metal without joints on its surface, which is called seamless steel pipe.

2. Different uses

Welded steel pipe: it can be used as water gas pipe, large-diameter straight seam welded pipe for high-pressure oil and gas transmission, etc.; spiral welded pipe for oil and gas transmission, pipe pile, pier, etc.

Seamless steel pipe: it is used for petroleum geological drilling pipe, cracking pipe for petrochemical industry, boiler pipe, bearing pipe and high-precision structural steel pipe for automobile, tractor and aviation.

Spiral welded pipes in Haihao Group

Spiral welded pipes in Haihao Group

3. Different classification

Welded steel pipe: according to different welding methods, it can be divided into arc welded pipe, high frequency or low frequency resistance welded pipe, gas welded pipe, furnace welded pipe, Bondi pipe, etc. It can be divided into general welded pipe, galvanized welded pipe, oxygen blowing welded pipe, wire sleeve, metric welded pipe, idler pipe, deep well pump pipe, automobile pipe, transformer pipe, thin-wall electric welded pipe, special electric welded pipe and spiral welded pipe.

Seamless steel pipe: seamless pipe is divided into hot rolling pipe, cold rolling pipe, cold drawing pipe, extrusion pipe, pipe jacking, etc. According to the section shape, seamless steel pipe can be divided into two types: circular and special-shaped. According to different purposes, there are thick wall pipe and thin wall pipe.

Haihao Group manufacture steel pipes products more than 30 years,the products sells well all over the world for the high quality.If you have any question,please contact us! Email:sales@haihaogroup.com