Issues related to the construction of water supply and drainage pipelines
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Dear Haihao friends! My project has 2 circulating water pipelines. Some pipes need to be buried underground because they have to cross roads. The main pipe is DN400, and according to the design requirements, a DN600 steel protective sleeve is needed for the pipeline running through it. So the question arises: once the pipeline is placed in the trench, how should the gap between the main DN400 pipe and the DN600 protective sleeve be dealt with? Which specification should be referred to for such specific construction requirements? Welcome to the discussion, thank you!
Waterproof sleeve, atlas number 02S404
Hello, this is a waterproof sleeve. The sleeves we use here are designed to protect pipes from damage caused by ground pressure; they are different from regular sleeves.
Personally, I think there’s no need to take any action, as the purpose of installing protective sleeves is to safeguard the main pipe from being damaged by heavy vehicles on the road. If a rigid seal is installed between the sleeve and the main pipe, making them one unit, then what’s the difference from not having any protection at all?
There are no requirements for non-destructive testing of the welds in the waterproof sleeves; what the original poster is referring to are the connection welds of the pipes that are covered by these waterproof sleeves
Having worked on many projects, I’ve seen cases where the pipes were buried directly, as well as those with sleeves installed. The sleeves could be made of concrete or steel, but I’ve never seen any filling used to fill the gaps between them.
Generally, the diameter of the sleeve is two sizes larger than that of the embedded pipe; no treatment is required for the gap between the sleeve, and this can be found in the reference manuals
Generally, no action is required for this. Casing is used to protect the pipes passing through it; a larger diameter and wall thickness are selected as long as they can withstand the applied forces. But be sure to take anti-corrosion measures for the two pipelines.
Okay, the work has been completed according to these requirements; the pipes have been concealed and the damaged road surface has been repaired.