Size of steel pipe
Different methods are used to express the dimensions of steel tubes in different standards. Today, we will introduce in detail the method of expressing the wall thickness of steel tubes, the method of expressing the outer diameter of steel tubes, and the comparison table of steel tube sizes.
Three ways to express the wall thickness of steel pipe
1) it is represented by the Sch.
For carbon steel tube wall thickness: Sch10, 20, 30, 40, 60, 80, 100, 120, 140, 160, etc. 10 grades (if the number is added S, stainless steel tube); for stainless steel wall thickness series: 5S, 10S, 40S, 80S four grades
2) it is expressed in pipe weight, such as STD (standard weight), XS (thickened tube), and XXS (special thick tube)
3), which is expressed as the thickness of steel tube, that is, "pipe diameter x wall thickness", such as φ 89X4.
The representation method of pipe diameter
The meaning of De, DN, D, d, and φ diameter
One,Generally speaking, the diameter of the pipe can be divided into outer diameter (De), inner diameter (D) and nominal diameter (DN).
1, DN refers to the nominal diameter of the pipe, which is the mean value of the outer diameter and the inner diameter. The value of the value of DN =De is -0.5* tube wall thickness. Note: This is neither the outer diameter nor the inner diameter.
Water and gas pipeline (galvanized steel pipe or non galvanized steel pipe), cast iron pipe, steel plastic composite pipe and polyvinyl chloride (PVC) pipe should be marked with nominal diameter "DN" (such as DN15, DN50).
2, De mainly refers to the pipe diameter, PPR, PE pipe, polypropylene tube external diameter, generally using De, all need to be labeled as outer diameter * thickness of the form, example De25 x 3.
3, D generally refers to the inner diameter of the pipe.
4, d diameter concrete pipe diameter. The diameter of reinforced concrete (or concrete) pipes, clay pipes, acid resistant ceramic pipes and cylinder pipes should be expressed in D (such as D230, D380, etc.).
5, the diameter represents the diameter of the common circle, or the outer diameter of the tube, but at this time it should be multiplied by the wall thickness. For example, the diameter is 25 x 3, and the diameter is 25mm and the wall thickness is 3mm. For seamless steel pipe or non-ferrous metal pipe, "outer diameter * wall thickness" should be marked. For example, it is 108 * 4, which can be omitted. In China, ISO and Japan, part of the standard of steel pipe adopts wall thickness to represent the thickness of steel tube. The method for the specification of this kind of steel pipe is pipe diameter and wall thickness. For example, 60.5 x 3.8. Such
6, DN is Nominal diameter, meaning nominal diameter. The 7, De, external diameter means the outer diameter.
8, Dg diameter Gong (the initials of the Chinese phonetic alphabet), then you can see that Dg is a homemade product with Chinese characteristics.
Two. The way of expression of the pipe diameter:
1 "water, gas transportation pipe (galvanized or non Galvanized), cast iron pipes and plastic pipes, etc., shall be marked with nominal diameter" DN "(such as DN15 and DN50).
2 pipe materials such as seamless steel pipe, welded pipe (straight seam or spiral seam), copper pipe and stainless steel tube, the pipe diameter should be expressed as outer diameter and wall thickness (such as De108 * 4, De159 x 4.5 etc.).
For seamless steel pipe or non-ferrous metal pipe, "outer diameter * wall thickness" should be marked. For example, it is 108 * 4, which can be omitted.
3 reinforced concrete (or concrete) pipes, clay pipes, acid resistant ceramic pipes, and cylinder head pipes, etc. the diameter of pipes should be expressed in D (such as D230, D380, etc.).
4, plastic pipe, pipe diameter should be expressed in accordance with product standards.
5. When the design is used to represent the diameter of the nominal diameter DN, the nominal diameter DN and the corresponding product specifications shall be given.
Three. The respective ranges of De, DN, d and φ
1, De--PPR, PE, polypropylene pipe and outer diameter.
1, De--PPR, PE, polypropylene pipe and outer diameter.
2, DN-- polyvinyl chloride (PVC) pipe, cast iron pipe, steel plastic composite pipe, galvanized steel pipe nominal diameter of
3, d - the nominal diameter of concrete pipe.
4, φ- seamless pipe or non-ferrous metal pipeline should be marked "outer diameter * wall thickness", such as: 108 X 4
Four.Other explanations
Nominal diameter (nominal diameter), also known as the mean outer diameter (mean outside outside diameter). In order to unify the connection dimensions of pipes and fittings, the nominal diameter (also known as nominal diameter and nominal diameter) is represented by DN. It
Because the unit has the distinction between the metric system (mm) and the British system (inch), there are the following ways of addressing. 1, on the basis of mm, referred to as DN (metric unit) 2, based on the British system (inch), called NB (inch unit) 3, DN
Steel pipe dimensions chart ansi b36.10 and b36.19
