Deflection Fitting

[lakee911]

I've seen expansion fittings, but is there such a thing as a deflection fitting for movement in the other direction (plane)? How would I prevent conduit from sheering off at a foundation from frost heave if it's direct bury?

Thanks,
Jason

 

[tkb]

OZ Gedney makes an expansion/deflection fitting.
It is pricey though and for rigid.

If you are worried about the shearing at the foundation then, use a length of rigid to go through the foundation and then change over to PVC.

 

[Cavie]

they do make expantion/deflection for PVC.

 

[lakee911]

OZ Gedney makes an expansion/deflection fitting.
It is pricey though and for rigid.

By rigid I'm guessing you mean RGS or something like that, not PVC, right?

If you are worried about the shearing at the foundation then, use a length of rigid to go through the foundation and then change over to PVC.

That won't do me any good because it'll then just sheer off after the "rigid."

they do make expantion/deflection for PVC.

Got a link by any chance?

Thanks,
Jason

 

[LarryFine]

That won't do me any good because it'll then just sheer off after the "rigid."

If it's that bad that far away from the building, it sounds like you need RGS the whole way.

 

[lakee911]

I don't see how it's got anything to do w/ the distance from the building. Building goes up and conduit doesn't, right?

 

[M. D.]

I found this here

 

[Smart $]

...

Got a link by any chance?

...

http://electrolines.com/Images/Line Card/Catalogs/Rigid_PVC_Conduit_Fittings_Catalog.PDF

See catalog page 23 (pdf page 25).

Note proper use is not specified. I'm of the impression two are required per run, especially for short distances between moving conduits held rigidly in place with their surroundings... in addition to premium granular backfill through and somewhat beyond the deflection area.

 

[tkb]

Yes "rigid" is RGS conduit.
Wher I am "rigid" usually means RGS and not PVC.

See page 8 for the deflection fitting like the picture above.
http://www.o-zgedney.com/PDF/OZG_CA_ExpansionFittingswithIntegralBond[1].pdf

 

[lakee911]

Can I use a piece of flex? Can that go underground? I'm looking for something PVC.

 

[Smart $]

Can I use a piece of flex? Can that go underground? I'm looking for something PVC.

You can use LFMC or LFNC for direct burial where listed and marked for the purpose [350.10(3), 356.10(4)].

 

[lakee911]

You can use LFMC or LFNC for direct burial where listed and marked for the purpose [350.10(3), 356.10(4)].

Thank you, sir. I will investigate that.

Jason

 

[tkb]

That won't do me any good because it'll then just sheer off after the "rigid."

I don't think so.

The shear could happen at the foundation. The foundation would not move and the ground outside lifts with frost.

If the conduit was RGS for at least 5' from the foundation and then changed to PVC, the conduit would follow the lift and not break off.
It may bend at the foundation, but since there is nothing to shear against out 5' from the wall, it would stay intact.

 

[Cavie]

http://press.kscdirect.com/?p=333