Difference Between Stainless Steel Seamless Pipe And Stainless Steel Welded Pipe

What is seamless stainless steel pipe?

Stainless steel seamless steel pipe is a long steel with a hollow cross section and no seams around it.

Features of stainless steel seamless pipe

First, the thicker the wall thickness of the pipe, the more economical and practical it is, and the thinner the wall thickness, the higher its processing cost;
Secondly, the technology of this product determines its limited performance. Generally, the accuracy of seamless steel pipes is low: uneven wall thickness, low brightness on the inside and outside of the tube, high cost of fixed length, and pits and black spots on the inside and outside are not easy to remove;
Third, its detection and shaping must be processed offline. Therefore, it shows its superiority in terms of high pressure, high strength, and mechanical structural materials.

Specification and appearance quality of stainless steel seamless pipe

A. According to GB14975-94 “Stainless Steel Seamless Steel Pipe”, steel pipes usually have a length (indefinite length) of hot-rolled steel pipes of 1.5-10m, and hot-extruded steel pipes are equal to and greater than 1m. The thickness of cold drawn (rolled) steel pipe is 0.5 to 1.0mm, 1.0 to 7m; the thickness of cold drawn (rolled) steel pipe is 1.5 to 8m.
B. There are 45 kinds of hot-rolled (hot-extruded) stainless steel welded pipes with a diameter of 54 to 480mm; 36 kinds of wall thicknesses of 4.5 to 45mm. There are 65 types of cold-drawn (rolled) steel pipes with a diameter of 6 to 200 mm; 39 types of wall thicknesses of 0.5 to 21 mm.
C. There must be no cracks, folds, cracks, cracks, creases, delaminations, and scars on the inner and outer surfaces of the steel pipe. These defects should be completely removed (except for mechanical processing pipes). Diameter exceeds negative deviation. Other minor surface defects not exceeding the allowable negative deviation may not be removed.
D. Straight allowable depth. Hot-rolled, hot-extruded steel pipe, diameter less than or equal to 140mm, not more than 5% of the nominal wall thickness, and the maximum depth of not more than 0.5mm; cold-drawn (rolled) steel pipe is not more than 4% of the nominal wall thickness, and the maximum depth is not more than 0.3 mm.
E. Both ends of the steel pipe should be cut at right angles, and burrs should be removed.

Stainless steel seamless pipe is a long steel with a hollow cross section and no seams around it. The wall thickness is uneven, and the internal and external brightness of the pipe is low.

It is generally used as a material for high strength and high pressure structures.

The blanks of stainless steel welded pipes are mainly steel plates and strip steel, which are generally divided into spot welded pipes, welded pipes, automatic arc welded pipes or spiral welded pipes and straight seam pipes according to the welding form.

Stainless steel seamless pipes can be divided into hot-rolled seamless steel pipes and cold-drawn seamless steel pipes according to the manufacturing process.

From the perspective of production technology, stainless steel welded pipe production equipment is simple, and it is relatively easy to change the product specifications and varieties. The welding process generally uses inert gas shielded arc welding, which reduces the cost by 25% compared with the seamless pipe of the same specification. The manufacturing process is relatively complicated and requires high production equipment. Each link will affect the quality of stainless steel seamless pipes.

From the perspective of production use, welded pipes are mainly used to transport water, oil, gas, air, and generally lower pressure fluids such as hot water or steam, and other uses. Some welded pipes can also be used for mine pressure, drainage, shaft fangs and other aspects.

Stainless steel seamless pipe can be used in engineering and large-scale equipment to transport fluid pipelines, and can also be used in power station and nuclear power plant boilers to withstand high temperature and high pressure fluid transport headers and pipes.