HDPE Pipe Depth and Backfill Material 2

[SmallInfo]

Hi experts,
One of our client replacing CS cooling water buried network with HDPE in gas plant.
1)Does any code/standard recommend how deep we can go or is there any calculation for this to safe pipe from load?
2)Does any code/standard recommend what should be the backfill material for HDPE pipe?
Thanks

 

[LittleInch]

The plastic pipeinstitute produce a very comprehensive guideline which you can download chapter by chapter

https://plasticpipe.org/Shared_Content/Shop/PE-Handbook.aspx

GPS UK provide a very useful and comprehensive design guide

http://www.gpsuk.com/uploads/docs/1636.pdf

Deep - Yes - usually done for collapse, but 1m cover should be fine for all sizes

They like sand or filtered soil, but in reality it is very accommodating to hard elements, but try not to drop large rocks on it....

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Agnul93]

Hi. As LittleInch already pointed out, PPI is very good reference.
I found very useful also ASTM D2774 "Standard Practice for Underground Installation of Thermoplastic Pressure Piping": this standard defines in a detailed way how backfill should be done: other topics e.g. trench depth (min. 24inch of cover where overhead traffic is expected), installation precautions etc. are described.
AWWA manual M55 is also a good reference: inside you can find several indication and detailed calculation formulas for external loads etc.

 

[SmallInfo]

Thank you Agnul93 and Littleinch, it really helped