In the late 1990s, thin wall Stainless steel pipe It has just started production and use Stainless steel water pipe The emerging new generation in the field has been widely used in the pipeline of building water supply and direct drinking water.

The thin-walled stainless steel pipe has been recognized by the engineering community after a long time of use, and the relevant parties are starting from reducing the wall thickness and price to facilitate further promotion. In particular, the price of small diameter stainless steel pipe is not high, so the supporting connection method, reliability and price of pipe fittings are the main factors determining its development.

Thin wall stainless steel tube is a promising tube. The Ministry of Construction and relevant departments also attach great importance to this new type of pipe. According to China's Technology Market Management Promotion Center, GKSZ [2001] No. 71 document, the notice on the promotion and application of "high-precision stainless steel medium and high pressure water supply pipes with high diameter wall ratio, supporting pipe fittings and special technology" was learned, The popularization and application of this technology and product of thin-walled stainless steel pipe is of great significance to improve the grade of modern buildings in China, and to change and ensure the quality of water supply.

At the same time, the Ministry of Construction attaches great importance to the promotion and application of thin-walled stainless steel pipes. The industry standard of Thin wall Stainless Steel Water Pipe was issued and implemented in 2001. The Ministry of Construction has issued relevant technical regulations and installation drawings for pipeline engineering, which are being prepared by Tongji University.

1. Cold drawing deep processing

It is easy to generate friction heat, so use stainless steel pipes with high pressure resistance and heat resistance, and remove the oil attached to the surface after forming and processing.

2. Welding

Before welding, all rust, oil, moisture, paint, etc. harmful to welding shall be removed, and welding rod suitable for steel type shall be selected. The time interval of spot welding is shorter than that of carbon steel spot welding. Stainless steel pipe brush shall be used to remove welding slag. After welding, the surface shall be grinded or cleaned to prevent local corrosion or strength decline.

3. Cutting and stamping

As stainless steel pipes have higher strength than ordinary materials, higher pressure is required for stamping and shearing, and poor shear and work hardening can not occur when the gap between knives is accurate. Plasma or laser cutting is used. When gas cutting or arc cutting is necessary, the heat affected zone is ground and heat treatment is required.

4. Bending

Thin plates can be bent to 180, but in order to reduce the crack on the bending surface that is twice the thickness of the plate with the same radius, it is necessary to give the thick plate a radius of twice the thickness when it is bent along the rolling direction, and a radius of four times the thickness of the plate when it is bent perpendicular to the rolling direction. Especially during welding, the surface of the welding area should be ground to prevent processing cracks.