The spiral tube is also called a spiral steel pipe or a spiral tube. It is rolled into a tube blanket at the angle of the spiral line (called the forming angle) of the steel or low alloy structure steel belt at a certain spiral line, and then welded the pipe seams. , It can produce large steel pipes with narrow steel steel.
1. There are several types of spiral steel tubes with a diameter of 100mm 102*5, 108*5, etc. 108 is the outer diameter of the spiral steel pipe, 5 indicates the wall thickness of the spiral steel pipe. ) = 98mm, but it is not exactly equal to the difference between the outer diameter of the steel pipe.
2. It can also be said that the nominal diameter is close to the inner diameter, but it is not equal to the specifications of the diameter of the diameter of the inner diameter. In the design drawing, the nominal diameter should be used. The size and connection size of valves, flanges, pads, etc., the nominal diameter is represented by symbol DN.
3. If the outer diameter is used in the design drawings, the pipeline specifications should also be made to indicate the nominal diameter and thick wall of the nominal pipeline.
4. Spiral steel pipes are generally used for transmission of low -voltage fluids (that is, water, liquid gas). The outer diameter of the steel pipe is generally represented by D or ф. Generally speaking, the diameter of the spiral steel pipe can be divided into outer diameter, inner diameter, and nominal diameter. It means that the method can be divided into the following types: the outer diameter D of the spiral steel pipe of the pipe is expressed by the diameter of the spiral steel pipe. Wall thickness, such as a spiral steel pipe with 108 outer diameter, 5mm wall thickness, expressed by D108*5, plastic tubes are also represented by outer diameter, such as DE63.
5. Others such as reinforced concrete pipes, cast iron pipes, galvanized steel pipes, etc. are expressed by DN. The nominal diameter is generally expressed in design drawings. The nominal diameter is the specification name of the spiral steel pipe (or pipe). The nominal diameter of the spiral steel pipe is not equal to its inner diameter and outer diameter.
