Water treatment - Chemical dosing pipeline material

[JohnWeal]

I have specified PVCu pipelines for the chemicals which we are dosing at one of our water treatment sites.
We are providing 3 systems,
1) Polymer
2) Polyaluminium chloride
3) Alum

It has been suggested to me that I should change the material to PE100 (or HDPE) as the pipelines range from 100 metres to 200 metres. The pipelines are installed below ground in covered trenches and also lagged due to temperatures going as low as -10 degrees C during some winter nights.
The hottest is around +50 degrees C.

I would be grateful for your comments. In all the dosing systems I have done I have never actually specified HDPE or PE100.

I guess they may be issues of supporting he pipe but also I'm thinking possible effects of the viscosity. (Only a guess as I don't know for sure)
The polymer dosing will use progressive cavity pumps. The PACL and ALUM will use diaphragm pumps.

Many thanks for your help.

Best Regards
John

 

[LittleInch]

Pe de-rates above 20C and at 50 is about 40% from memory.

not sure why PE would be thought of as better than PVCu

PE is more flexible and is suitable for burial without any other requirements so maybe more suited compared to PVC to a longer not completely flat burial.



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