What is the difference between pipe diameter DN and De?
DN refers to the nominal diameter of the pipeline. Note: This is neither the outer diameter nor the inner diameter. It should be related to the British system unit in the early stage of pipeline engineering development. It is usually used to describe the galvanized steel pipe. Its corresponding relationship with the British system unit is as follows: 4 branch pipes: 4 / 8 inch: DN15; 6 branch pipes: 6 / 8 inch: DN20; 1 inch pipe: 1 inch: DN25; 2 inch pipes: 1 and 1 / 4 inch: DN32;
Inch half pipe: 1 and 1 / 2 inch: Dn40;
Two inch pipe: 2 inch: DN50;
Three inch pipe: 3 inch: DN80 (many places are also marked as dn75);
Four inch pipe: 4 inch: DN100;
De mainly refers to the outer diameter of the pipe, which is generally marked by De, and needs to be marked in the form of outer diameter x wall thickness; it is mainly used to describe: seamless steel pipe, PVC and other plastic pipes, and other pipes that need to be clear about the wall thickness. Take galvanized welded steel pipe as an example, two marking methods of DN and de are as follows: DN20 de25 × 2.5mm.
DN25 De32×3mm
DN32 De40×4mm
DN40 De50×4mm
We are accustomed to using DN to mark welded steel pipes, and rarely use De to mark pipes without involving the wall thickness; however, marking plastic pipes is another matter; it is still related to the industry habit. In the actual construction process, the 20, 25, 32 and other pipes we abbreviated refer to de rather than DN, which is different from one specification. It is easy to cause losses in the process of purchase and construction if not clear.
The connection of two kinds of pipe materials is nothing more than screw connection and flange connection. Other connections are rarely used.
Galvanized steel pipe and PPR pipe can adopt the above two kinds of connection, but the screw thread is more convenient for the pipe less than 50, and the flange is more reliable for the pipe greater than 50.
Note: if the metal pipes of two different materials are connected, consider whether there will be galvanic cell reaction, otherwise it will accelerate the corrosion rate of the active metal pipes. It is better to use flange connection, and separate the two metals with rubber gasket insulation materials, including bolts, to avoid contact.
![What is the difference between pipe diameter DN and De?]( "What is the difference between pipe diameter DN and De?")
on rate of the active metal pipes. It is better to use flange connection, and separate the two metals with rubber gasket insulation materials, including bolts, to avoid contact.
The respective ranges of De, DN, D and ф! De -- PPR, PE pipe, polypropylene pipe od DN -- Polyethylene (PVC) pipe, cast iron pipe, steel plastic composite pipe, galvanized steel pipe nominal diameter a
D -- nominal diameter of concrete pipe
ф -- nominal diameter of seamless steel pipe, the specification is, such as ф 100:108 × 4
DN15-ф22mm，DN20-ф27mm ，
DN25-ф34mm，DN32-ф42mm，
DN40-ф48mm，DN50-ф60mm ，
DN65-ф76(73)mm，DN80-ф89mm ，
DN100-ф114mm，DN125-ф140mm ，
DN150-ф168mm，DN200-ф219mm ，
DN250-ф273mm，DN300-ф324mm ，
DN350-ф360mm，DN400-ф406mm ，
DN450-ф457mm，DN500-ф508mm，
DN600-ф610mm，DN15-ф18mm，
DN20-ф25mm ，DN25-ф32mm，
DN32-ф38mm ，DN40-ф45mm，
DN50-ф57mm ，DN65-ф73mm，
DN80-ф89mm，DN100-ф108mm，
DN125-ф133mm ，DN150-ф159mm，
DN200-ф219mm ，DN250-ф273mm，
DN300-ф325mm，DN350-ф377mm，
DN400-ф426mm ，DN450-ф480mm，
DN500-ф530mm ，DN600-ф630mm。