There are many types of pipes to choose from,generally divided into metal pipes,lined plastic pipes,and plastic pipes such as PE pipes.Currently,more and more pipeline installation projects are choosing to use PE pipes instead of cast iron pipes.So,what are the advantages of PE pipes compared to cast iron pipes,and why are they so popular?
1.Strength and stiffness
On the surface,PE pipes are inferior to cast iron pipes.But when subjected to external pressure load,the mechanism of load bearing for flexible pipes and cast iron pipes is completely different:flexible pipes can undergo significant deformation before being subjected to compression failure,while cast iron pipes cannot.Under the same external pressure load,the stress inside the flexible pipe wall is relatively small,and it and the surrounding backfill soil jointly bear the load,acting together with the pipe and soil.Therefore,PE material pipes do not need to have the same strength and stiffness as rigid cast iron pipes.With reasonable stiffness,they can fully meet the requirements for use.
2.Hydraulic characteristic ratio
Due to its smooth inner wall,PE pipes have significantly lower frictional resistance when transporting liquids compared to cast iron pipes.The inner wall roughness of the pipe is 0.001,while that of the cast iron pipe is 0.013.Therefore,under the same usage conditions,the former can increase the water delivery capacity by 30%compared to the cast iron pipe.

3. Sealing of interfaces
The connection of PE pipes is relatively reliable. However, it is relatively difficult to ensure the sealing of cast iron pipes. The majority of flat joints used in China are difficult to ensure no leakage over time; Moreover, due to its completely rigid connection, even slight displacement of the pipeline (such as uneven soil settlement) may cause damage to the connection and result in leakage.
4. Service life and corrosion resistance
The advantages of PE pipes are quite prominent. The domestic sewage and rainwater transported by buried drainage pipes are corrosive (rainwater often dissolves into corrosive substances when flowing through the ground), acidic or alkaline, and industrial wastewater such as industrial drainage is highly corrosive. The former has much better corrosion resistance than cast iron pipes.
From the above content, we can understand that PE pipes are significantly better than cast iron pipes in terms of conveying capacity, sealing performance, and service life. Moreover, cast iron pipes are more difficult to transport and construct due to their heavy weight, while PE pipes are much easier to transport, which can effectively shorten the construction period and save construction costs.