The difference between stainless steel pipe diameter DN and DE

1. 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 imperial unit in the early stage of pipeline engineering development; it is usually used to describe the galvanized steel pipe, and its corresponding relationship with the imperial unit is as follows: 4 Responsibility: 4/8 inch: DN15; 6 Responsibility: 6/8 inch: DN20; 1 inch pipe: 1 inch: DN25; inch second pipe: 1 and 1/4 inch: DN32; inch half pipe: 1 and 1/2 Inch: DN40; Two-inch pipe: 2 inches: DN50; Three-inch pipe: 3 inches: DN80 (also marked as DN75 in many places); Four-inch pipe: 4 inches: DN100; 2. De mainly refers to the outer diameter of the pipe, generally Those marked with De need to be marked in the form of outer diameter X wall thickness; mainly used to describe: seamless steel pipes, PVC and other plastic pipes, and other pipes that require a clear wall thickness. Take the galvanized welded steel pipe as an example. The two labeling methods of DN and De are as follows: DN20 De25×2.5mm DN25 De32×3mmDN32 De40×4mm DN40 De50×4mm etc... We are used to using DN to label welded steel pipes. In the case of wall thickness, De is rarely used to label pipes; but labeling plastic pipes is another matter; it is still related to industry habits. In the actual construction process, the pipes 20, 25, 32, etc. that we abbreviate all refer to De, not DN, there is a difference here. Failure to figure it out can easily cause losses in the procurement and construction process. The connection of the two pipe materials is nothing more than: threaded connection and flange connection. Other connection methods are rarely used. Both galvanized steel pipes and PPR pipes can be connected by the above two types, but it is more convenient to use threaded fasteners for pipes smaller than 50, and flanges for pipes larger than 50 are more reliable. Note: If two metal pipes of different materials are connected, consider whether there will be a galvanic reaction, otherwise it will accelerate the corrosion rate of the active metal pipe. It is best to use flange connection and use rubber gaskets to connect the two Separate all kinds of metals, including bolts, with spacers to avoid contact. The respective ranges of De, DN, d, and ф! De--PPR, PE pipe, polypropylene pipe outer diameter DN--Polyethylene (PVC) pipe, cast iron pipe, steel-plastic composite pipe, galvanized steel pipe nominal diameter ad --Concrete pipe nominal diameter ф--Seamless steel pipe nominal diameter Diameter, its specifications are, such as ф100: 108 × 4DN15-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.