How do I connect a threaded 2" pvc pipe to a 1" non-threaded pipe?
#1
06-16-20, 07:10 AM
How do I connect a threaded pvc pipe to a non-threaded pipe?
Hi, where my sink drains it connects to a 2" threaded pipe (supposed to anyway). My drain pipes under the sink are 1", no threads, just the pvc out of the s/j-trap. How do I connect these two? That pvc pipe going into the bigger pvc pipe has no threads, just comes out of the trap under the sink. I tried to look up the part, but apparently it doesn't exist anymore.
Thanks for any help.
Edit: I don't know if it is right, but to get the pipe sizes I used a tape measure for the inside of the pipe diameter.
Edit: Measurements are wrong. I think it is 1 1/4 x 2"?
Edit
Thanks for any help.
Edit: I don't know if it is right, but to get the pipe sizes I used a tape measure for the inside of the pipe diameter.
Edit: Measurements are wrong. I think it is 1 1/4 x 2"?
Edit
Last edited by MrWishToFixIt; 06-16-20 at 07:31 AM.
#2
06-16-20, 07:52 AM
Join Date: Jan 2008
Location: Southeastern Pennsylvania
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hi MrWish–
To convert to threaded you use an adapter. There are both male and female adapters. This is just an example of a female adapter:
https://www.homedepot.com/p/2-in-PVC...E&gclsrc=aw.ds
You have to measure the outside of the pipe to determine NPT pipe size – not the inner diameter. Pipe thickness can vary for a given pipe size (e.g., a 1 inch pipe) but the outer diameter wont vary. For example a 1 1/2 pipe (schedules 40/80/120 represent different pipe thickness but O.D is the same):
O.D = 1.9”
schedule 40 I.D = 1.592”
schedule 80 I.D = 1.476”
schedule 120 I.D = 1.423”
So 3 different I.D's for the 1 1/2" pipe size
Here is a good link for pipe sizes:
Notes on Pipe
To convert to threaded you use an adapter. There are both male and female adapters. This is just an example of a female adapter:
https://www.homedepot.com/p/2-in-PVC...E&gclsrc=aw.ds
You have to measure the outside of the pipe to determine NPT pipe size – not the inner diameter. Pipe thickness can vary for a given pipe size (e.g., a 1 inch pipe) but the outer diameter wont vary. For example a 1 1/2 pipe (schedules 40/80/120 represent different pipe thickness but O.D is the same):
O.D = 1.9”
schedule 40 I.D = 1.592”
schedule 80 I.D = 1.476”
schedule 120 I.D = 1.423”
So 3 different I.D's for the 1 1/2" pipe size
Here is a good link for pipe sizes:
Notes on Pipe
#3
06-16-20, 09:51 AM
You need a trap adapter. I can't tell if that's 1.5" or 2" coming out of the wall, but you already have half (the cemented portion) of the trap adapter there. You just need the screw-on piece. (Though I don't think HD sells just that piece)
https://www.homedepot.com/p/NIBCO-2-...7HD2/100344161
The trap adapter can adapt to 1.5" slip PVC or 1.25" slip PVC which is what's coming out of the sink.
Nice and easy solution!
https://www.homedepot.com/p/NIBCO-2-...7HD2/100344161
The trap adapter can adapt to 1.5" slip PVC or 1.25" slip PVC which is what's coming out of the sink.
Nice and easy solution!
#4
06-16-20, 10:25 AM
Thanks. I probably did the wrong thing but I ended up using a flexible coupler and wrenched it down tight. I got 1 1/4 to 1 1/2, but I think maybe it was too big on the 1/4 side, but I got it on the there tight. I then looked up the trap adapter. Now I have to see if that is better.
https://www.plumbingsupply.com/trap-adapters.html
I got it from lowes, but it looks like that.
https://www.plumbingsupply.com/trap-adapters.html
I got it from lowes, but it looks like that.
#6
06-17-20, 07:54 AM
Join Date: Jan 2008
Location: Southeastern Pennsylvania
Posts: 3,104
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MrWish-
I didn’t recognize that the pipe in your pic was part of a trap (I didn’t even recognize that was a wall –lol), but fortunately Zorfdt did. Why not do what Zorfdt recommended? I think a rigid setup is supposed to be much better. I think flexible traps themselves are not to code – although in your present case it’s a flexible adapter and not the trap itself, so I think that’s different.
But still, it seems like it is recommended that you only use flexible stuff if there is no other way – I believe.
I didn’t recognize that the pipe in your pic was part of a trap (I didn’t even recognize that was a wall –lol), but fortunately Zorfdt did. Why not do what Zorfdt recommended? I think a rigid setup is supposed to be much better. I think flexible traps themselves are not to code – although in your present case it’s a flexible adapter and not the trap itself, so I think that’s different.
But still, it seems like it is recommended that you only use flexible stuff if there is no other way – I believe.
#7
06-17-20, 10:15 AM
No worries Zoesdad, that's why we're all here!
The reason the 1-1/4" rubber adapter didn't really fit right is that it's probably expecting a 1-1/4" Schedule 40 PVC, not the slip fit (which might be equivalent to schedule 10 or similar). If it's not leaking, the rubber fittings are fine. But I think a trap adapter ring would finish it correctly.
The reason the 1-1/4" rubber adapter didn't really fit right is that it's probably expecting a 1-1/4" Schedule 40 PVC, not the slip fit (which might be equivalent to schedule 10 or similar). If it's not leaking, the rubber fittings are fine. But I think a trap adapter ring would finish it correctly.
