Have been digging up some conduits the past few days that go into a building underground. There are 15 pipes entering the building below grade. Noticed for some reason all the pipes have pvc expansion joints buried underground for some reason. Are these couplings rated to be underground?
Expansion coupling
- Thread starter fireryan
- Start date
- Status
ptonsparky
Tom
- Occupation
- EC - retired
IIRC, at one time some inspectors were wanting expansion joints in long runs of buried pvc, thinking the runs would expand/contract.
Splicing conduits would certainly be easier with one especially if they met in the middle. Repairs are definitely easier.
Splicing conduits would certainly be easier with one especially if they met in the middle. Repairs are definitely easier.
RICK NAPIER
Senior Member
- Location
- New Jersey
My business was at the shore we used them when we where in sandy conditions since the conduit would move all over the place.
kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
I have sandy soil in maybe over 75% of areas I work in, never used an expansion fitting underground, never uncovered a broken raceway except if it were damaged by excavation equipment. You need to place raceway in bottom of trench or compact as you backfill or it may have some stress from settlement.
On top of that when burying lines to center pivot irrigation equipment have had runs of 1300 to 2800 feet on fairly regular basis, and many of those we even use a non listed thin walled PVC pipe, primarily for rodent protection otherwise we would have used direct bury conductor only, but we still run direct bury conductors/cables inside this pipe because it is not listed.
Never seen such a pipe come apart without help from excavation equipment or because of soil erosion or other shallow depth conditions and farming machinery ends up catching the line. When farm machinery catches the line you have more problems then just a broken pipe, conductors involved pull terminals right off of equipment quite often.
More recent years has become more popular to use HDPE conduit with conductors already installed - no expansion fittings used there either.
On top of that when burying lines to center pivot irrigation equipment have had runs of 1300 to 2800 feet on fairly regular basis, and many of those we even use a non listed thin walled PVC pipe, primarily for rodent protection otherwise we would have used direct bury conductor only, but we still run direct bury conductors/cables inside this pipe because it is not listed.
Never seen such a pipe come apart without help from excavation equipment or because of soil erosion or other shallow depth conditions and farming machinery ends up catching the line. When farm machinery catches the line you have more problems then just a broken pipe, conductors involved pull terminals right off of equipment quite often.
More recent years has become more popular to use HDPE conduit with conductors already installed - no expansion fittings used there either.
- Status