(1) The scale of seamless steel pipe wall thickness cover is relatively wide, and it can achieve small diameter and large wall thickness and large diameter and large wall thickness, but the length is generally limited (only a small number of manufacturers can produce ultra-long pipes); The wall thickness of stainless steel welded pipe can be relatively thin, and it can achieve large diameter and small wall thickness and small diameter and small wall thickness. In general, the thicker the seamless, the thinner, the welded pipe.

(2) In terms of uniformity and concentricity of wall thickness, stainless steel welded pipe is better than stainless steel seamless pipe. Because the thickness tolerance of the cold-rolled plate is relatively uniform, the deformation is uniform during the forming process. However, the weld is protruding, and different companies and specifications have different welding requirements, especially in special cases, it can be welded first and then cold-drawn or cold-rolled; In the process of seamless pipe rolling, affected by the accuracy of equipment, material function and other factors, there are problems of uneven thickness and concentricity, but the roundness is better than that of welded pipe.

(3) Function, the uniformity of stainless steel welded pipe is better and the surface quality is better. The function of the expansion tube is better. The functional uniformity of cold-rolled plate is better than that of pipes, and welded pipes are generally used in online solid solution, uniform heat treatment, and more stable function. However, there is no heat treatment process for low-end stainless steel welded pipes on the market, so the quality varies greatly. Stainless steel seamless pipes are sampled in different directions on the same pipe, and the functions are different, and some may be quite different. During the heat treatment of seamless tubes, there are uneven heating and inconsistent cooling rates during the treatment of bundles of heat pipes.

(4) The corrosion resistance function is appropriate. The weld has been heat treated and has now reached the material requirements. If there is no heat-treated stainless steel welded pipe, the corrosion resistance function is greatly reduced compared with the stainless steel seamless pipe.

(5) The production cost of welded pipe is lower and more environmentally friendly. A good welded pipe factory can be in a proper environment with the electronics factory; The seamless pipe factory is full of oil and lubricants, and the pickling environment is even worse.

(6) The pressure is not the same. Under the same specification conditions, stainless steel seamless pipes are subjected to higher pressures than welded pipes.

(7) The price is not the same. Overall, stainless steel seamless pipes are more expensive than welded pipes. However, there are also the following characteristics: if it is a thick-walled pipe, it is suitable to use seamless pipe, and if it is a thin-walled pipe, it is suitable to use welded pipe.

(8) The delivery cycle is different, because the stainless steel welded pipe is rolled with stainless steel plate, the processing is relatively simple, so the delivery time is shorter. Stainless steel seamless pipes should start from round steel, and then go through multiple passes of cold drawing/cold rolling after perforation, and then go through solution annealing and pickling before the products are produced, and the production cycle is longer.