Sink Trap Woes

[joe hawkins]

Hi,
I've tried 2 plumbing supply stores and they all tell me that plumbing companies will intentionally make a non-standard thread so I will always be forced to use their brand. Problem is that this company went out of business. Is there any truth to this?

Here is the old trap (house was built in 1979 in Bakersfield, CA) compared to another trap I purchased at Home Depot. They are close but will not thread onto each other. Any idea what's going on?

Thank you in advance.

 

[Reach4]

Is this for a kitchen or laundry? Is the pipe 1.9 inches diameter?

I was going to suggest that rather than trying to reuse that trap piece, I would cut the 1.9 inch OD pipe, put on a new escutcheon, and glue on a 1-1/2 inch pipe adapter. Then use a new slip joint trap. However Los Angeles may insist on a glued-on trap.

 

[Sponsor]

 

[wwhitney]

FWIW, I don't see any LA amendment (on up.codes) to UPC 1002.3, which allows one slip-joint fitting on the outlet side of a trap.

https://up.codes/viewer/los_angeles/ca-plumbing-code-2019/chapter/10/traps-and-interceptors#1003.2

Cheers, Wayne

1003.2 Slip Joint Fittings

A maximum of one approved slip joint fitting shall be permitted to be used on the outlet side of a trap, and no tubing trap shall be installed without a listed tubing trap adapter. Listed plastic trap adapters shall be permitted to be used to connect listed metal tubing traps.

 

[joe hawkins]

Is this for a kitchen or laundry? Is the pipe 1.9 inches diameter?

I was going to suggest that rather than trying to reuse that trap piece, I would cut the 1.9 inch OD pipe, put on a new escutcheon, and glue on a 1-1/2 inch pipe adapter. Then use a new slip joint trap. However Los Angeles may insist on a glued-on trap.

 

[joe hawkins]

Hi, it's for the bathroom sink. I'll measure the OD and get back.

A few questions if you don't mind :
1) Can I cut the pipe and go straight to a slip joint (skip the pipe adapter) like the one pictured in the attachment?
2) If not, can I use a fernco connector to the trap?

I'd prefer not to glue if possible.

Thank you

 

[Reach4]

FWIW, I don't see any LA amendment (on up.codes) to UPC 1002.3, which allows one slip-joint fitting on the outlet side of a trap.

Cool. There is what is called an "L.A. Pattern P-Trap" which is not slip joint at its exit. So I feared they might have a no-slip-downstream of-the-U rule.

 

[wwhitney]

Cool. There is what is called an "L.A. Pattern P-Trap" which is not slip joint at its exit. So I feared they might have a no-slip-downstream of-the-U rule.

Yeah, that has me wondering as well. So either it's an old requirement no longer in force, or it's in some other part of the LA code and they failed to properly coordinate 1003.2, or up.codes has it wrong. I.e. I wouldn't call the one lookup a definitive answer, just a very strongly suggestive one.

Cheers, Wayne

 

[Reach4]

Can I cut the pipe and go straight to a slip joint (skip the pipe adapter) like the one pictured in the attachment?

I am not familiar with that trap. Got a link for that one?

If that is a slip joint at its output that grabs 1.9 inch OD pipe, you will have limited adjustability.
So the sink tailpiece would have to be on the arc that that sweeps. A classic trap has more levels of adjustment, so that the trap arm can be the length needed. If that is a 1.5 inch slip joint output (more probable I would think), it would be too big to go on 1.9 inch OD 1-1/2 inch pipe.

With a lavatory, you can use a 1-1/4 inch trap, and with the right washer in the trap adapter, that can fit into the 1-1/2 inch trap adapter. The other way to do it is to use a 1-1/2 trap, and convert from the 1-1/4 inch tailpiece at the input of the trap.

 

[wwhitney]

With a lavatory, you can use a 1-1/4 inch trap, and with the right washer in the trap adapter, that can fit into the 1-1/2 inch trap adapter. The other way to do it is to use a 1-1/2 trap, and convert from the 1-1/4 inch tailpiece at the input of the trap.

Under the UPC, the former limits the trap arm to 30" (which would be fine if there's a san-tee for venting right inside the wall), while the latter allows a 42" trap arm.

Cheers, Wayne

 

[joe hawkins]

I am not familiar with that trap. Got a link for that one?

If that is a slip joint at its output that grabs 1.9 inch OD pipe, you will have limited adjustability.
So the sink tailpiece would have to be on the arc that that sweeps. A classic trap has more levels of adjustment, so that the trap arm can be the length needed. If that is a 1.5 inch slip joint output (more probable I would think), it would be too big to go on 1.9 inch OD 1-1/2 inch pipe.

With a lavatory, you can use a 1-1/4 inch trap, and with the right washer in the trap adapter, that can fit into the 1-1/2 inch trap adapter. The other way to do it is to use a 1-1/2 trap, and convert from the 1-1/4 inch tailpiece at the input of the trap.

Thanks for the response

Here's a link for that trap.
https://www.danco.com/product/1-12-in-slip-joint-swivel-p-trap-in-white/

Any thoughts on using a fernco from the metal pipe to the trap?

 

[wwhitney]

The slip joint outlet on that trap appears to be a regular 1.5" tubular slip joint, not something special that would fit on a Schedule 40 1.5" (1.9" OD) pipe. So it's not helpful for your situation.

You could use a Fernco 3002-120 with a regular slip joint trap if you don't want to learn how to solvent weld on a trap adapter (although it's not hard).

https://www.fernco.com/dimensional-drawings/3002-150

Cheers, Wayne

 

[joe hawkins]

The slip joint outlet on that trap appears to be a regular 1.5" tubular slip joint, not something special that would fit on a Schedule 40 1.5" (1.9" OD) pipe. So it's not helpful for your situation.

You could use a Fernco 3002-120 with a regular slip joint trap if you don't want to learn how to solvent weld on a trap adapter (although it's not hard).

https://www.fernco.com/dimensional-drawings/3002-150

Cheers, Wayne

Thank you. Really appreciate your help.