Conduit Cleaning

[charlie b]

What is the name of the tool you pull through old conduit to clean out rust and clean out other rough surfaces before pulling new conductors?

I am reviewing a project that will require pulling 300 kcmil through two existing 3" conduits, one presently spare. Both are many decades old and are installed under the foundation of a lock (i.e., allowing boats to traverse between waterways). The design package does not include any instructions for the contractor to verify that the conduit interior surfaces do not impose a risk to the new conductor insulation.

Should I raise an issue?

 

[infinity]

Ball and brush. The ball ensures that the conduit is not crushed.

 

[dkidd]

What is the name of the tool you pull through old conduit to clean out rust and clean out other rough surfaces before pulling new conductors?

I am reviewing a project that will require pulling 300 kcmil through two existing 3" conduits, one presently spare. Both are many decades old and are installed under the foundation of a lock (i.e., allowing boats to traverse between waterways). The design package does not include any instructions for the contractor to verify that the conduit interior surfaces do not impose a risk to the new conductor insulation.

Should I raise an issue?

I have always specified using a mandrel

See

Underground conduit cleaning

Does anyone know of a method, or preferably have experience, for cleaning partially blocked RMC - underground and concrete encased? More specifically several feeds (3/4" & 1") in a duct bank that have not fared so well after years of water, dirt, ash, and acid infiltration. Cleaning / Rodding /...

forums.mikeholt.com

 

[Seven-Delta-FortyOne]

Proving and cleaning with a Mandrel is required on underground conduits here, before the POCO will pull their conductors through. They even specify the type and brand(s) of mandrel.

 

[zbang]

To answer the question- I'd definitely raise this, and possibly call for a camera inspection after passing the mandrel.

 

[infinity]

If you can pull to proper sized mandrel through the existing conduit that would be good enough for me. After that I wouldn't hesitate to pull in the conductors. Now if you think that the conduit may be deteriorated that's a different issue.

 

[roger]

Ball and brush. The ball ensures that the conduit is not crushed.

We had them on our line trucks and used them mostly for larger underground of conduits

 

[zbang]

Now if you think that the conduit may be deteriorated that's a different issue.

Decades old and under water...... probably metal, too... Unless they're in concrete the whole way, I'd be pleasantly surprised if they're not damaged.

 

[infinity]

Decades old and under water...... probably metal, too... Unless they're in concrete the whole way, I'd be pleasantly surprised if they're not damaged.

Could be damaged but he didn't say what kind of conduit. Could be PVC or PVC coated RMC which should last a long time even under adverse conditions.

 

[zbang]

Could be any material, but no one knows unless they look.

 

[LarryFine]

If there is still a tunnel, whether it be made of steel, rust, or dirt, I'd happily pull in direct-bury wires.