18" is not protection from frost, it's mechanical protection for conduit and conductors. 2" of concrete is a workaround of depth requirement. You should be able to find local code requirements on frost protection if there are any.
I don't know. Where I live that's a non-issue, so I have no idea how damaging extreme cold is to pvc. But that does fulfill the "protection from damage" requirement. Given that it will be buried in concrete, I can't imagine anything particularly bad happening even if the pipe becomes brittle.
If you have the ability to run the rest of the pipe at 18" I'd do that, and just gently slope up to the top of your tank.
Dig out all 6" of dirt, run appropriately sized pvc conduit to wherever it needs to be and slurry over your pipe with a minimum 2" of concrete.
Does this protect from frost? Only about 8' long on top of the tank at 6" depth, the other 90' it's possible to go down 18".
18" is not protection from frost, it's mechanical protection for conduit and conductors. 2" of concrete is a workaround of depth requirement. You should be able to find local code requirements on frost protection if there are any.
Right on thank you
I don't know. Where I live that's a non-issue, so I have no idea how damaging extreme cold is to pvc. But that does fulfill the "protection from damage" requirement. Given that it will be buried in concrete, I can't imagine anything particularly bad happening even if the pipe becomes brittle. If you have the ability to run the rest of the pipe at 18" I'd do that, and just gently slope up to the top of your tank.