Conduit Expansion Fittings - When Needed?

[Spudland_Dave]

When do you need to install the Conduit Expansion Fittings?

I ask because even on my own house with the same electrician, I have a "Mix", the Service Entrance has an expansion sleeve, the 2 Low-Volt conduits do not, driving around I've been paying attention and its 50/50...I'm a fan of doing things right, so now is the time to get it right.

So I'll be coming out of the house with an LB...down into the ground...gonna go 36" deep, put a sweep on the conduit then let the cable be Direct buried all the way to the garage...at the garage, go into a sweep...up and into the building via LB there as well. Garage is a floating slab, house is a full basement. I live in Maine, it does freeze here...

Are expansion sleeves needed? Both ends?
Also, should I seal the conduit in the ground? If so with what? Spray Foam?

 

[W-Cummins]

My local AHJ wanted them on schedule 40 pvc and did not require it on sch 80 pvc. I needed to use them as I needed to stay with the sch 40, due to wire fill ( I didn't want to upsize to dual 4" runs) Of course the PowerCo ran a single 4" sch 40 w/o the expansion fitting into the CT box!

William....