Need a point of view....

[timothy.collins]

Does anyone know what drives the requirement for the wraping of RMC in corrosive soils? ie.; high alkaline soils. It appears the standard is wrapping of conduit with 10 mil tape to impede the corrosive process. Where does this standard come from? The Authority Having Jurisdiction... Where do they get their info?

 

[hbiss]

Re: Need a point of view....

I have never heard of that requirement. The NEC requires the use of a product (in this case conduit) that is suitable for use in the environment it is installed in. If the soil is corrosive to a certain material, wrapping it with tape is not a solution, using a listed product such as PVC or plastic coated RMC (Robroy) is.

-Hal

 

[don_resqcapt19]

Re: Need a point of view....

Hal,
There are corrosion protection wraps available for underground piping. In my opinion the use of these types of products to provide supplementary corrosion is permitted by 344.10(B) and by the UL listing information. The quote below is from the UL Guide for Rigid conduit.

Galvanized rigid steel conduit installed in contact with soil does not generally require supplementary corrosion protection.

Don

 

[hbiss]

Re: Need a point of view....

There are corrosion protection wraps available for underground piping.

Agreed, and its designed for the purpose and is certainly another option. That is not the same as wrapping the pipe with electrical tape however.


-Hal

 

[curt swartz]

Re: Need a point of view....

Hal

Timothy specified 10 mil tape not electrical tape so I assume he is talking about 10 mil pipe wrap tape which is sold for this purpose. Plumbers are required to wrap their underground metal gas pipe fittings with it. I frequently wrap RMC sweeps and stubs. In my area RMC will often be in very bad shape in a just a few years without providing some additional protection. Job spec will frequently require underground portions of RMC to be wrapped with 10m mil tape.

 

[tom baker]

Re: Need a point of view....

The 3M pipe wrap tape "50" is required to be used with a paint on primer. The primer is similar to contact cement.
What I like is the green pipe tape that the gas company uses. Its thicker and seems better.