352.44 expansion fittings

[mh183]

i have a 4" pvc 50' between 90's looking at the chart at 100 degrease f temperature change , i would have movement of 2.03 inches . and would need one fitting. or does the issue of expiation only apply for lengths over 100'

 

[infinity]

Since you're over 1/4" of expansion you would need an expansion fitting. The 100' is just the amount of expansion used in the table. At 50' you would have 4.06/2=2.03" of expansion which exceeds the 1/4".

352.44 Expansion Fittings.
Expansion fittings for PVC conduit shall be provided to compensate for thermal expansion and contraction where the length change, in accordance with Table 352.44, is expected to be 6 mm (? in.) or greater in a straight run between securely mounted items such as boxes, cabinets, elbows, or other conduit terminations.

 

[mh183]

yes thanks that's how i am reading it to