HDPE pipe manufacturers say that HDPE double-wall corrugated pipe ring stiffness refers to the pressure resistance of the pipe performance indicators, such as:
SN4 stands for the ring stiffness of hdpe double-walled bellows, that is, the pressure per square meter can withstand is greater than or equal to 4 kN.
Note: SN4 is also called S1, that is, SN4≥4KN/㎡. SN4:4KN/㎡.
SN8 stands for the ring stiffness of hdpe double-walled bellows, that is, the pressure that can withstand per square meter is greater than or equal to 8 kN.
Note: SN8 is also called S2, that is, SN8≥8KN/M2. SN8:8KN/㎡.
That translates roughly to a pressure per square meter greater than or equal to; this is a numerical measure of ring stiffness and the grade of pipe.
HDPE double-wall bellows: The difference between hdpe double-wall bellows and hdpe double-wall wound pipes
HDPE plastic steel winding pipe is made of special shaped steel and plastic composite strip by spiral winding welding, its inner wall is smooth. This kind of pipe has the advantages of corrosion resistance, light weight, easy installation, large flow rate, lengthy service life (50 years), etc. It can replace the pipe made of high energy consumption materials (cement, cast iron, ceramic, etc.), belonging to environmental protection green products.
HDPE double-wall bellows were first developed in Germany in the early 1980s. It is a modern type of lightweight pipe made of high density polyethylene. It has the characteristics of light weight, strong pressure resistance, excellent toughness, quick construction and long service life. Its excellent pipe wall structure design considerably reduces the cost compared with pipes of other structures. And because the connection is convenient and reliable, it has been widely used at home and abroad.