Stainless steel pipes are widely used in the national economy, ranging from pipes for nuclear power plants and ships to handrails for residential buildings. They are an important product in the steel industry. Common materials include 201/304/316L. According to the production method, stainless steel pipes are divided into two categories: stainless steel welded pipes and stainless steel seamless pipes. What is the difference between the two?

process difference

1. Stainless steel welded pipe: It is welded by steel plate or steel strip after crimping and forming by the machine unit and mold. Different welding methods can be divided into straight seam stainless steel welded pipes and spiral stainless steel welded pipes. The production efficiency of stainless steel welded pipe is high, and there are many varieties and specifications. Moreover, the welded pipe avoids multiple heating processes during the processing, and the production process is more environmentally friendly.

2. Stainless steel seamless pipe: After heating the round pipe billet, it is made by cold rolling, cold drawing or hot extrusion production process. The thicker the wall thickness of the product, the more economical and practical it is, and the thinner the wall thickness, the higher its processing cost will be.

difference in appearance

1. Stainless steel welded pipe: Due to the cold forming process of the plate, the steel pipe has high precision, uniform wall thickness, and high brightness inside and outside the pipe (the surface brightness of the steel pipe is determined by the surface grade of the steel plate). The size can be arbitrarily fixed, and the steel tube sizes chart is rich, especially in the large diameter and thin wall.

2. Stainless steel seamless pipe: The steel pipe has low precision and uneven wall thickness. Due to the limitation of processing methods, the inner and outer surfaces of the pipe have low brightness and high cost of cutting to length. Usually the walls are thicker.

performance difference

1. In terms of usage habits, seamless pipes are mostly used in projects that require performance such as corrosion resistance and pressure and high temperature resistance due to their better metal structure uniformity. Traditional enterprises such as boilers, power stations, and pressure vessels favor seamless steel pipes.

2. Since the 1930s, with the rapid development of continuous rolling production of high-quality strip steel and the advancement of welding and inspection technology, the quality of welds has continued to improve, and the varieties and specifications of welded steel pipes have increased day by day. The application scenarios of stainless steel welded pipes have expanded from decorative pipes, product pipes and low-pressure fluid pipes to nuclear power equipment, high-pressure pipes, special material fluids, medical care, healthy drinking water and other industries.

price difference

The seamless pipe is more complicated in the production process, and its price is more expensive than the stainless steel welded pipe.

difference in application

1. Stainless steel welded pipe: With its good surface effect, it is often used as decorative pipe, prop pipe, and product pipe. It is mainly used to transport water, oil, gas, air, and general low-pressure fluids such as heating water or steam.

2. Stainless steel seamless pipe: With its good corrosion resistance, pressure bearing and high temperature resistance, it is often used in engineering and large-scale equipment to transport fluid pipelines, and can also be used as high temperature and high pressure fluid transmission pipelines such as power stations.