DN Nominal diameter
De external diameter
Dg diameter gong (the initials of the Chinese pinyin "gong") Now you will understand that Dg is a domestic product, and a domestic product with Chinese characteristics is no longer needed.
The relationship between DN, De, Dg, Φ
De measures the diameter of the outer wall of the pipe
DN is the number obtained by halving the thickness of the pipe wall from De
Dg is generally not used
Φ represents the diameter of an ordinary circle
The pipe diameter should be in mm, and the expression of pipe diameter should meet the following requirements:
For pipes such as steel pipes (galvanized or non-galvanized) and cast iron pipes for water gas transportation, the pipe diameter should be expressed by the nominal diameter DN;
For seamless steel pipes, welded steel pipes (straight seam or spiral seam), copper pipes, stainless steel pipes and other pipes, the pipe diameter should be expressed in terms of outer diameter × wall thickness Φ;
For pipes such as reinforced concrete (or concrete) pipes, clay pipes, acid-resistant ceramic pipes, cylinder tile pipes, etc., the pipe diameter should be expressed as the inner diameter d;
For plastic pipes, the pipe diameter should be expressed in accordance with the product standard method;
When the design uses the nominal diameter DN to indicate the pipe diameter, there should be a comparison table between the nominal diameter DN and the corresponding product specifications.
The specifications of rigid polyvinyl chloride pipes for building drainage are represented by de (nominal outer diameter) × e (nominal wall thickness) (GB 5836.1-92), and the specifications of polypropylene (PP) pipes for water supply are represented by de × e (nominal outer diameter × Wall thickness) The marking of the plastic pipe on the engineering drawing.
Metric dimension size
Expressed by DN, it is generally called the "nominal size", which is not the outer diameter of the pipe nor the inner diameter of the pipe. It is the average of the outer diameter and the inner diameter, we call the average inner diameter.
For example: Metric marking (mm dimension size) DN50 for plastic pipes with an outer diameter of 63mm
ISO metric dimension size
Da represents the outer diameter of PVC pipe and ABS pipe
Denote the outer diameter of PP pipe and PE pipe
For example: Metric marking (mm dimension size) for plastic pipes with an outer diameter of 63mm
Da63 is for PVC pipes and ABS pipes.
Summary: De, DN, d, and ф respectively indicate the range!
De-- PPR, PE pipe, polypropylene pipe outer diameter
DN--Nominal diameter of polyethylene (PVC) pipe, cast iron pipe, steel-plastic composite pipe, galvanized steel pipe
d - Nominal diameter of concrete pipe
ф-- Seamless steel pipes or non-ferrous metal pipes should be marked with "outer diameter × wall thickness"
