Definition of HDPE Double-Wall Ribbed Pipe 
Using HDPE resin as the raw material and adding various additives, it is processed and extruded by plastic molding equipment. This type of pipe is a new kind of pipe composed of a corrugated outer structure layer and a smooth solid inner wall. 
The origin of the raw materials for HDPE double-wall corrugated pipes 
The company's raw materials are all imported from well-known foreign manufacturers. The main suppliers are the American Phillips Company and the Japanese Asahi Kasei Corporation. Among them, the resin used is the TR490 produced by the American Phillips Company; the color masterbatch used is the MB9140 produced by the Japanese Asahi Kasei Corporation. 
The implementation standards for HDPE double-wall corrugated pipes 
National Standard GB/T19472.1-2004 "Underground Polyethylene (PE) Structured Wall Pipeline Systems - Part 1: Polyethylene Double-Wall Corrugated Pipe Materials". 
What are the product specifications of HDPE double-wall corrugated pipes? 
DN/ID (mm) 225, 300, 400, 500, 600, 710. 
Product features of HDPE double-wall corrugated pipe 
(1) Low construction cost: Compared with steel pipes, it can save 30-50%; compared with cement, the overall cost is basically the same; compared with fiberglass reinforced sand pipe, it only requires 1/5 of the construction cost; compared with the same type of HDPE hollow coiled pipe, it can also save 25-50%, and the maintenance cost is extremely low, being 1/5 of that of other pipe materials. 
(2) Stronger resistance to pressure: The scientific organizational structure and high hoop stiffness of the pipe material have enhanced the pipe's ability to resist soil loads. This performance is an advantage of the double-wall corrugated pipe compared to other structural walls. 
(3) High density, light weight, and convenient construction: HDPE is the abbreviation of High-Density Polyethylene. Its molecular weight ranges from 70,000 to 150,000, with a density of 0.941 to 0.965. It is lightweight, being one-eighth the weight of steel pipes and one-tenth that of cement pipes. This significantly reduces transportation costs and installation overheads such as lifting. The construction process is fast, and it can be connected using socket-joint, Havel type, or pipe fittings. 
⑷ Resistance to chemical corrosion: Polyethylene is an inert material that can withstand various chemical media such as acids, alkalis, and salts, without any electrochemical corrosion. It is an excellent anti-corrosion material in itself. Up to now, no reagent in the world can dissolve polyethylene. Common factors such as soil, acids and alkalis, and electricity will not cause damage to the pipeline. 
(5) Appropriate flexibility, good dynamic fracture toughness value KD, excellent seismic resistance: Due to the inherent properties of HDPE material, when subjected to external force, the pipe can undergo certain bending deformation without breaking, and it can quickly transfer the resistance effectively. The PE corrugated pipe has a very good resistance to ground subsidence caused by underground movements (especially earthquakes), and it can adapt to complex terrain trenches. In April 2001, a 5.9 magnitude earthquake occurred in Baoquan District, Yunnan Province. The PE pipe remained intact, while all other underground pipelines were completely damaged. Therefore, PE material is currently the best pipeline material in terms of seismic resistance. 
(6) Excellent hygiene performance: The molecular structure of PE material is CH2. Even if it is decomposed, it remains safe and non-toxic. PE material is of food hygiene grade and is used in low-pressure water supply systems, without causing secondary pollution. 
⑺ Smooth inner wall, low water resistance, no scaling: The inner wall of the PE corrugated pipe is very smooth. The absolute roughness K value of the inner wall does not exceed 0.01mm, while for steel pipe and ductile iron pipe, K = 0.06mm. After 10 years of operation of metal pipes, the K value will increase by 5-10 times. However, the molecular surface of the PE material does not carry positive or negative charges, and the charged impurities in water will not adhere to the pipe wall to form scale. Therefore, the flow rate is also very large. For pipes of the same diameter and the same pressure, the flow rate of the PE pipe is 1/4 larger than that of the metal pipe. 
(8) Excellent low-temperature resistance: The normal operating temperature range of PE corrugated pipes is from -40 degrees to 60 degrees. The temperature range is quite wide, and they can be used normally even in extremely cold conditions of -30 degrees. PE pipes are the only type of pipe that won't crack in freezing conditions. 
(9) Excellent impact resistance: Among all the plastic pipes currently available in the market (PVC, PP, ABS, PB), PE has the best impact strength. Through tests, the impact strength of PE is 6 times that of PVC and 4 times that of PP. 
(10) Excellent electrical insulation performance: The majority of the PE molecular chains are composed of methylene groups and do not contain polar groups, thus having extremely excellent dielectric properties. Within the current frequency range of 50-100 hertz, the dielectric constant and dielectric loss tangent of HDPE are independent of the current frequency, making it particularly suitable as an insulation material for high-frequency power supplies and electrical appliances. PE is a very good insulating material. The outer insulation layer of wires and cables is mostly made of PE. The double-wall corrugated PE pipe can be used as the direct burial sheath pipe for cables or cast into concrete, serving as the cable sheath pipe market being very popular. Various performance indicators are much stronger than those of PVC cable sheath pipes. 
(11) Excellent sealing performance - no leakage: There are two connection methods for the PE double-wall corrugated pipe: (1) Socket connection (2) Hafke compression connection. Both of these connection methods can achieve almost no leakage because they are relatively traditional connection methods. They have been very successful and mature in use abroad. Many domestic projects have also adopted them. Based on the usage experience, they are all quite good. The leakage rate can be controlled within 2%, effectively controlling the pollution of groundwater resources. It benefits the present and lasts for thousands of years. 
(12) Long service life: The working environment of PE corrugated pipes is buried in the soil, free from ultraviolet radiation, and the working temperature is not high, generally ranging from 12 degrees to 25 degrees. Therefore, the service life can be guaranteed to be 50 years, basically synchronizing with the lifespan of the building.