What Is a Stainless Steel Tube?
Stainless steel tubes are simply tubes that are made of stainless steel.
If there is no specific specification, steel piping is used from the standpoint of cost, but stainless steel tubes are used when rust is to be prevented. There are different types of stainless steel, so selection should be based on detailed applications and budget.
Three main types of stainless steel tubes exist: structural, piping, and heat-transfer. Within each type there are different types, such as thin-walled and thick-walled, seamless and welded, and so on.
Uses of Stainless Steel Tubes
Stainless steel pipes are used in many rust-prone situations because of their high resistance to rust. Specific applications are as follows:
- Feed water piping for steam boilers used in power generation
- Cooling seawater piping in petrochemical complexes
- Circulating liquid piping for flue gas desulfurization equipment
- Piping for transporting chemicals, pure water, and tap water
However, even stainless steel can rust, it is important to note that stainless steel pipes do not rust, but rather are resistant to rust.
Principle of Stainless Steel Tubes
Stainless steel tubes are an alloy of chromium or nickel mixed with iron. To begin with, rust occurs when iron reacts with oxygen in the air to form iron oxide.
Since stainless steel contains chromium, chromium combines with oxygen before iron to prevent rust. When the chromium oxidizes, it forms a passive film of several nanometers on the surface. The passive film is characterized by its resistance to chemical change. Thus, it serves to prevent oxygen from bonding with iron.
When stainless steel is scratched, the passive film may peel off, but the chromium will soon oxidize to form a new passive film.
Other Information on Stainless Steel Tubes
1. Bending of Stainless Steel Tubes
Stainless steel tubes are used in a variety of locations, including plumbing in the home. In order to use stainless steel tubes, it is necessary to bend them into a shape suitable for the application. Stainless steel is a difficult material to process, but there are several bending methods.
- Pipe Bender Method
This is the most common processing method. A special tool or machine is used to bend the pipe. There is almost no distortion or other deformation when bending, and it is possible to finish with a high degree of accuracy. Furthermore, this simple processing method can be performed at low cost. - Gas Seared Hand Bending Method
The gas seared hand bending method is a processing method in which stainless steel tubes are seared with a gas flame to soften them before bending. It is possible to perform complex and difficult bending processing.
2. Threading of Stainless Steel Tubes
Threading of stainless steel tubes is a process used for applications such as gas and water pipes. Threading is performed using a threading machine. The threading machine consists of a die head, chaser, and other parts.
Die heads come in various types depending on the threading length and diameter, and are replaced depending on the application. The chaser is a processing blade for threading. Various types are available depending on the threading length and thread diameter. Since stainless steel tubes are hard, the chaser used should be a part for stainless steel tubes.