expansion fittings requirements

[Stevenfyeager]

What are pvc max lengths that don't need an expansion fitting ? We recently ran a circuit in 3/4 " pvc 45 ' under a deck and didn't think of an expansion fitting. I realize it will get no sun. I have seen pvc in sunlight have problems. Thanks

 

[tom baker]

Look at the pvc expansion table for the max temp change, how much is it? That expansion has to be accommodated by the conduit bowing or pulling out of the joints.
However being under the dock will lessen the heat gain from solar
More than 1/4” expansion is the limit.
A run between two boxes is an issue with expansion. I did a job on reo sides of a house, one side was between an LB and Palmer- expansion ftg there, other side was from LB under a deck and turned down into ground, that side had someplace for expansion to go where it turned down into dirt.

 

[don_resqcapt19]

In your state you probably have around 100°F of change over the course of the year, and that results in about 4" per 100', so you run would be well over 1/4" of expansion.