HDPE Penstock Pipe

[Everynameistaken]

Hello Civil Friends,

I have a question regarding the application of buried HDPE Pressure pipe.

We have an HDPE penstock that is conveying power flow for a micro hydro power station. The pipeline is almost 3 km long and we have done our best to optimise the DR of the pipes as we travel up the hill. When we get near the top the pipe is not longer governed by the pressure as the static head on the pipe is quite small. At this location we have to decide how large a DR rating do we go?

At 16" HDPE pipe we can have DR 26 which has 5/8" wall and DR 32.5 which has 1/2" wall. Does anyone have any experience with handling and installing this size and thickness pipe? Is there a worry with the DR 32.5 pipe and the thinner wall when handing, and backfilling, and heat welding, and dragging along the road for installation?

Any thoughts from the forum would be much appreciated.

PS the pipe here will not be driven on my any heavy vehicle, perhaps a pick-up but more likely only and ATV.

 

[ashtree]

The poly pipe manufacturers publish extensive information regarding installation , handling and loadings etc. This would be a good starting point.

Regards
Ashtree
"Any water can be made potable if you filter it through enough money"

 

[bimr]

It may be possible to pull vacuum on higher sections of the pipeline when the pipe is draining.

 

[Everynameistaken]

Hi,

Thanks for the initial responses.

I have looked at the manufactures literature, however Im sure they are going to tell me their products is great without any issues, but I would like to see if people have un-biased experience with this?

It is likely the pipe will pull a vacuum when the turbine shuts down and the water hammer goes up and down the pipe, I will calculate my buckling resistance under vacuum pressure so this may dictate that 32 is not even suitable

 

[QualityTime]

Lots of HDPE pipe failures. Read about it

 

[hydrae]

Have you checked the material that is available at your local supply house. I had an application where I wanted to use the highest DR HDPE to save weight (as a insulation jacket on a pipe over a bridge) the local supplier only had DR 26 available.

Hydrae