Transition of RGS conduit to PVC conduit

[Charz]

I have a situation where there is a transition of RGS Metal conduit from above ground to PVC conduit Under ground. The spec says to use " a threaded PVC to rigid metal conduit adapter" for transition.


Can somebody help me to send the catalogues of the manufacturer for the required adapter. I googled it and couldn't get the required adapter.

 

[SceneryDriver]

Female threads on one side, and solvent weld on the other.. Pick trade size to suit:

https://www.homedepot.com/p/3-4-in-Female-Conduit-Adapter-R5140044/202043515

My opinion is to avoid male threads in PVC if at all possible. The male threads are thinner walled, and are more prone to breakage than the pipe wall or female adapters.



SceneryDriver

 

[Gary11734]

That would be a PVC Female adaptor.

 

[LarryFine]

Female threads on one side, and solvent weld on the other.. Pick trade size to suit:

I was expecting to see an adapter with both metal and plastic, like a plumbing adapter:

 

[Coppersmith]

Although the inspector would probably not complain about

RMC-rigid coupling-PVC male adapter-PVC,

it's not technically compliant since both the male adapter and rigid coupling have straight threads. The coupling has to connect to something with angled threads. The correct assembly would be

RMC-rigid coupling-close nipple-PVC female adapter-PVC.

 

[LarryFine]

The correct assembly would be

RMC-rigid coupling-close nipple-PVC female adapter-PVC.

Why not RMC-PVC female adapter-PVC? Omit the nipple and coupling.

 

[electrofelon]

Although the inspector would probably not complain about

RMC-rigid coupling-PVC male adapter-PVC,

it's not technically compliant since both the male adapter and rigid coupling have straight threads. The coupling has to connect to something with angled threads. The correct assembly would be

RMC-rigid coupling-close nipple-PVC female adapter-PVC.

Can you cite a source that states the tapered/non tapered threads are an issue? I understand some fittings are listed/instructions dont mention a certain combination, but I have never seen different thread taper given as the reason.

 

[Coppersmith]

Why not RMC-PVC female adapter-PVC? Omit the nipple and coupling.

You are correct Larry. I was thinking about how I connect a PVC riser to a Myers hub and got confused.

Can you cite a source that states the tapered/non tapered threads are an issue? I understand some fittings are listed/instructions dont mention a certain combination, but I have never seen different thread taper given as the reason.

We have discussed this issue several times on the forum. I used to connect a male adapter into a rigid coupling until I was convinced otherwise by reading forum posts. I'll leave it to others to dredge up the posts.

 

[Carultch]

Although the inspector would probably not complain about

RMC-rigid coupling-PVC male adapter-PVC,

it's not technically compliant since both the male adapter and rigid coupling have straight threads. The coupling has to connect to something with angled threads.

I've NEVER seen a PVC male adapter for electrical that has straight threads. Perhaps this is a previous design, that is now obsolete. Given that these most likely do have tapered threads, does that change your answer on whether or not one can combine it with straight female threads on products built for RMC?

I see straight threads on all other kinds of connectors, and I see installations that plug them directly in conduit bodies and standard RMC couplings all the time, in spite of it not being a listed combination. LFMC connectors, EMT connectors, RMC threadless connectors, etc. The proper transitioning fittings, which would be analogous to a female adapter, are a lot more difficult to get.

 

[tkb]

Just slide the bell end over the RGS.
That is what the POCO does.

 

[electrofelon]

I've NEVER seen a PVC male adapter for electrical that has straight threads.

Really? Ive never seen one that was tapered :blink:

The different thread taper argument is just a pet peeve of mine. It gets thrown out there all the time without any justification. RGC couplings are not tapered and mate with tapered pipe.......

 

[Coppersmith]

I've NEVER seen a PVC male adapter for electrical that has straight threads. Perhaps this is a previous design, that is now obsolete. Given that these most likely do have tapered threads, does that change your answer on whether or not one can combine it with straight female threads on products built for RMC?

I see straight threads on all other kinds of connectors, and I see installations that plug them directly in conduit bodies and standard RMC couplings all the time, in spite of it not being a listed combination. LFMC connectors, EMT connectors, RMC threadless connectors, etc. The proper transitioning fittings, which would be analogous to a female adapter, are a lot more difficult to get.

PVC male adapters (AKA connectors) have straight threads. Try putting a locknut on one. If the threads were tapered, it would jam before hitting bottom.