What PVC part do I need in this photo?

[LCF]

One of my outbuildings has an entire copper stack, and replacing it is not an option right now. All the connections to the stack are from former sinks with 1-1/4 threaded connections, making it very easy to connect a nice new chrome drain pipe to it. My problem is that I am installing a new utility sink, which uses a standard 1-1/2" drain, and I also need the nipple to connect a dishwasher to the tailpipe. How do I connect 1-1/2" PVC to this old brass connection? I am hoping there is some sort of slip joint reducing adapter that will allow me to use the same style gasket over the PVC before I tighten the nut? I couldn't find anything on SupplyHouse. Thanks in advance for your help.

 

[Tuttles Revenge]

A kitchen or utility sink trap arm minimum size is 1-1/2"

The trap adapter in your photo likely reduces the trap arm from 1-1/2 to 1-1/4" at the threads. To replace it you would need to unsweat / unsolder the trap adapter from the pipe... which requires some skill. You would then be left with bare pipe which you could use a copper to plastic shielded coupling to adapt to the correct sized spigot trap adapter.

However you're as likely to remove the adapter as you are to take the pipe out of the san tee and be left with the need to solder in another copper stub.

 

[Sponsor]

 

[LCF]

A kitchen or utility sink trap arm minimum size is 1-1/2"

The trap adapter in your photo likely reduces the trap arm from 1-1/2 to 1-1/4" at the threads. To replace it you would need to unsweat / unsolder the trap adapter from the pipe... which requires some skill. You would then be left with bare pipe which you could use a copper to plastic shielded coupling to adapt to the correct sized spigot trap adapter.

However you're as likely to remove the adapter as you are to take the pipe out of the san tee and be left with the need to solder in another copper stub.

Do you have a photo of what one of these shielded couplings look like? I'll consider unsweating it if I can't find a reducing adapter to use as is. If your speaking about a Fernco, I would rather not use one of those.

 

[wwhitney]

Do you have a photo of what one of these shielded couplings look like?

Proflex 3001-150 or Mission Rubber CK-115 to adapt 1-1/2" copper to 1-1/2" plastic.

I'll consider unsweating it if I can't find a reducing adapter to use as is.

You can't connect a 1-1/2" trap arm to a 1-1/4" fitting, you need to unsweat the copper trap adapter if you need to use a 1-1/2" trap.

Just to confirm, if you take the nut off what you have, the threaded portion underneath is about 1.66" across, not 1.9" across?

Cheers, Wayne

 

[LCF]

Proflex 3001-150 or Mission Rubber CK-115 to adapt 1-1/2" copper to 1-1/2" plastic.


You can't connect a 1-1/2" trap arm to a 1-1/4" fitting, you need to unsweat the copper trap adapter if you need to use a 1-1/2" trap.

Just to confirm, if you take the nut off what you have, the threaded portion underneath is about 1.66" across, not 1.9" across?

Cheers, Wayne

Would something like this work? I would prefer adapt the 1 1/2 drain to fit into the copper pipe, rather than use a Fernco. The measurement with the nut removed are 1-1/4 so I believe the copper pipe is 1 1/2 but the current adapter reduces it.

 

[Tuttles Revenge]

There is two ways you can adapt to 1.5" threads without the Fernco adapter (which is the easiest way) But if you're skilled with a torch then these are great ways to get your connection.

A marvel ring, which is just a Brass threaded ring that you solder to the end of the pipe. It provides 1.5" threads and a FLAT face for FLAT washers to seal against.

Or a DWV soldered trap adapter which is the same as what you're taking off but provides you with a SLIP JOINT connection for use with beveled washers.

 

[LCF]

There is two ways you can adapt to 1.5" threads without the Fernco adapter (which is the easiest way) But if you're skilled with a torch then these are great ways to get your connection.

A marvel ring, which is just a Brass threaded ring that you solder to the end of the pipe. It provides 1.5" threads and a FLAT face for FLAT washers to seal against.

View attachment 94705

Or a DWV soldered trap adapter which is the same as what you're taking off but provides you with a SLIP JOINT connection for use with beveled washers.

View attachment 94706

Thank you! I'm not sure I'm skilled enough to properly sweat a join that size. I've only ever done smaller joints. I wish I had thought of this before the sheet rock went up! The existing brass adapter has one of those beveled washers inside but it will only take a 1 1/4 trap arm .

 

[wwhitney]

Can you confirm that the OD on the cast copper hub on the san-tee (the rearmost hub in the first picture) is about 1-3/4", not 1-1/2"?

If you don't want to solder, then your only option is a banded rubber coupling, as far as I know.

Cheers, Wayne

 

[Reach4]

Would something like this work? I would prefer adapt the 1 1/2 drain to fit into the copper pipe, rather than use a Fernco. The measurement with the nut removed are 1-1/4 so I believe the copper pipe is 1 1/2 but the current adapter reduces it.

If you have what I suspect you have, put the nut from your first photo back very loosely, stick a 1-1/2 inch slip joint trap into the hole, and tighten the nut. You may not have what I think, but I don't think you have 1-1/4 inch. The actual OD of 1-1/2 inch slip joint tubing is 1.50 inches.

Plastic slip joint stuff is cheap, even to buy a piece for sizing.

 

[wwhitney]

If you have what I suspect you have

The second photo shows the ID of the trap adapter is 1-1/4".

Cheers, Wayne

 

[Reach4]

The second photo shows the ID of the trap adapter is 1-1/4".
Cheers, Wayne

If that is the case, and the measurement was not due to parallax, then my suspicion was definitely wrong. Adapting to that existing thread would not be helpful, and would add almost nothing vs using a 1-1/4 inch trap IMO.

I wonder what is going on deeper.