Water pipe size

Water Pipe Size

For water pipes, homes use 4-way and 6-way pipes. For steel pipes and copper pipes, the 4-way pipe is marked as DN15, and the 6-way pipe is marked as DN20. The size of the 4-way pipe is 1/2 inch, and the inner diameter is about 12.7 mm. The inner diameter of the 6-way pipe is about 20 mm.

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 average value of the outer diameter and the inner diameter.

The value of DN = the value of De - 0.5 * the thickness of the pipe wall

Note: This is neither the outer diameter nor the inner diameter. Pipes such as water and gas transmission steel pipes (galvanized steel pipes or non-galvanized steel pipes), cast iron pipes, steel-plastic composite pipes, and polyvinyl chloride (PVC) pipes should be marked with the nominal diameter "DN" (such as DN15, DN50);

2. De mainly refers to the outer diameter of the pipe. The outer diameter of PPR, PE pipes, and polypropylene pipes are generally marked with De, and they all need to be marked in the form of outer diameter x wall thickness, such as De25 x 3;

3. D generally refers to the inner diameter of the pipe;

4. φ represents the diameter of a common circle; it can also represent the outer diameter of the pipe, but at this time it should be multiplied by the wall thickness. For example, φ25 x 3 means a pipe with an outer diameter of 25mm and a wall thickness of 3mm. For seamless steel pipes or nonferrous metal pipes, "outer diameter x wall thickness" should be marked. For example, φ108 x 4, φ can be omitted. Some steel pipe standards in China, ISO and Japan use wall thickness size to indicate the wall thickness series of steel pipes. The specification of this type of steel pipe is expressed as outer diameter x wall thickness. For example, φ60.5 x 3.8;

5. DN stands for Nominal diameter, which means nominal diameter;

6. De stands for external diameter, which means external diameter;