Quality testing: After the construction is completed, the quality of the polyethylene outer coating should be tested, mainly to check the thickness, adhesion, pinhole and other indicators of the coating. The coating thickness was measured by magnetic thickness gauge, the adhesion was measured by grid method, and the pinhole was detected by high voltage EDM tester. If the problem is found, timely repair or rework treatment to ensure the quality and protective performance of the outer coating.

The durability of ductile iron pipe network can be improved from the aspects of improving the performance of the pipe itself, strengthening external protection, controlling construction quality and optimizing operation and maintenance. The specific methods are as follows:

Adding alloying elements: In the production of ductile iron pipes, some alloying elements such as nickel, molybdenum, copper and so on are often added. These alloying elements can refine the grain, improve the strength and toughness of cast iron, and thus enhance the pressure resistance of the pipeline. For example, nickel can improve the toughness and fatigue resistance of cast iron, molybdenum can enhance the strength and hardness of cast iron, in some high-pressure pipeline, add the right amount of nickel and molybdenum, can make ductile iron pipe withstand higher pressure.

Ductile iron pipe is widely used in municipal water supply, drainage, gas transmission and other fields because of its excellent mechanical properties, corrosion resistance and economy. However, in the actual use process, the pipe network system may be affected by periodic load, temperature change, soil settlement and other factors, resulting in fatigue damage, which will affect the service life and safety of the pipeline.