How to do this double sink with Studor vent for center island?

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farmerjohn1324

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Is this the right configuration (plus garbage disposal)? The drain pipe is 1.5", does that mean they all must be 1.5" pipes?

Does it matter what height the Studor vent is at? Must it be above a certain level?

Should I have a cleanout under the sink? Is that too much?

trap part names3.jpg

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The trap is screwed together and is a clean out
I that picture the garburator goes on the left the vent wants to be high up close to the counter so a full sink would not put water up to the top. And it should not leak, don't push you luck.
 
The trap is screwed together and is a clean out
I that picture the garburator goes on the left the vent wants to be high up close to the counter so a full sink would not put water up to the top. And it should not leak, don't push you luck.

Basically, I should put the Studor Vent as high as it will go? Minimum of 4" above the trap?
 
How do I connect this Dual Outlet Valve to CPVC?

Do I just slide it over or do I need CPVC cement as well?

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How high should I put the water supply valves? Close to the bottom of the cabinet? In the middle?

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I would put them up to at least a foot from the underside of the counters. Do you have the faucet already? Does it come with attached hoses or do you need to add them?
 
I would put them up to at least a foot from the underside of the counters. Do you have the faucet already? Does it come with attached hoses or do you need to add them?

Do you mean a foot or closer to the countertop?

I haven't bought the faucet yet. Was gonna do that later today.
 
Do you mean a foot or closer to the countertop?

I haven't bought the faucet yet. Was gonna do that later today.

I would bring them up off the bottom of the cabinet probably about 18-20 inches. That way you'll use a connection hose that is about a foot long to connect the faucet to the valves.
 
Faucet may have supply tubes already attached, so buying the faucet first may help you decide where to put the stop valves. half way up sounds about right in any case, You want them to be accessible without too much fuss. I would have left the rough out of the pipes a good bit further up. it's going to be hard to attach anything there, and if it is not perfect, you won't see the problem until it becomes a bigger problem.
 
I have been reading that the AAV valve must be 6" above flood level. How is that even possible in a center island when it has to go in a sink cabinet?
 
Do the plumbing parts under the sink use regular PVC cement?

In every picture I see, it seems like they're held together by PVC that screws on to each other.
 
From what I understand the AAV must be a minimum of 4 inches above the trap weir. Generally you try to get it as high as you can where it can still have good airflow and you can access it to change it out should it fail.
Keep in mind that you still need to have the trap arm be at least two pipe diameters in length before it goes vertical.
https://www.familyhandyman.com/kitchen/how-to-plumb-an-island-sink/view-all/
AAVs are not allowed in some jurisdictions, so you might want to check with your local codes to find out if they are allowed.

Short answer: No, the tailpiece and P-trap do not use glue.
Generally a kitchen sink will use 1-1/2" PVC with slip joints (I think that is what they are called) or ABS fittings. For a double sink without a garbage disposal you might use something like this. The tailpipe, J-bend and so forth that make up the P-trap all fit together with the non-glued joints (this is so you can take apart the P-trap to clean out obstructions should it become clogged). After the trap arm, you would then use a trap adapter to convert from slip joint to non-threaded glue-on type.
That would glue on to a short run of PVC and connect to an 1-1/2 sanitary tee. On top would be another length of PVC with the AAV screwed in on the top and the bottom would go to a wye.
Although, it's possible that if the trap arm is the right thickness, it might not need the adapter. I'd have to ask someone who is familiar with that. ALL of the sinks in my house are S-trapped so I don't have a real-life version to look at that is correctly plumbed.
Does that help?

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Last edited:
From what I understand the AAV must be a minimum of 4 inches above the trap weir. Generally you try to get it as high as you can where it can still have good airflow and you can access it to change it out should it fail.
Keep in mind that you still need to have the trap arm be at least two pipe diameters in length before it goes vertical.
https://www.familyhandyman.com/kitchen/how-to-plumb-an-island-sink/view-all/
AAVs are not allowed in some jurisdictions, so you might want to check with your local codes to find out if they are allowed.

Short answer: No, the tailpiece and P-trap do not use glue.
Generally a kitchen sink will use 1-1/2" PVC with slip joints (I think that is what they are called) or ABS fittings. For a double sink without a garbage disposal you might use something like this. The tailpipe, J-bend and so forth that make up the P-trap all fit together with the non-glued joints (this is so you can take apart the P-trap to clean out obstructions should it become clogged). After the trap arm, you would then use a trap adapter to convert from slip joint to non-threaded glue-on type.
That would glue on to a short run of PVC and connect to an 1-1/2 sanitary tee. On top would be another length of PVC with the AAV screwed in on the top and the bottom would go to a wye.
Although, it's possible that if the trap arm is the right thickness, it might not need the adapter. I'd have to ask someone who is familiar with that. ALL of the sinks in my house are S-trapped so I don't have a real-life version to look at that is correctly plumbed.
Does that help?

Yes, that did help. Thank you.

I am confused why you say the final Tee goes down into a wye. Wouldn't it go down into the floor?

How much space do you think the AAV needs to breathe up top?

The P-Trap I bought seems to have glue fittings, unfortunately.

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Yes, that did help. Thank you.

I am confused why you say the final Tee goes down into a wye. Wouldn't it go down into the floor?

How much space do you think the AAV needs to breathe up top?

The P-Trap I bought seems to have glue fittings, unfortunately.

The final tee goes down into a wye below the floor. It connects to the main sewer line with a wye. Depending on where the sewer line is, it could be a regular wye or if it is a straight line to the sewer pipe, you'd use either a combo wye or a wye and 1/8 bend. You can not use a sanitary tee on it's back to connect to the main sewer line.

Maybe you can save the trap that you got for another project and get the appropriate kind that you twist together-- it can save you a lot of grief later on if you do it that way. I don't know if it is a code rule to use that type or not.

You would need at least enough room to get your hands on the AAV and pull it up-- it all depends on how much space you have under the sink. I would probably leave at least 3" to 6" from the top of the AAV and the underside of the sink/counter (depending on placement). I personally have never used AAVs yet because they were prohibited by my state's plumbing code (up until the code was reverted to IPC 2012).
 
The final tee goes down into a wye below the floor. It connects to the main sewer line with a wye. Depending on where the sewer line is, it could be a regular wye or if it is a straight line to the sewer pipe, you'd use either a combo wye or a wye and 1/8 bend. You can not use a sanitary tee on it's back to connect to the main sewer line.

Maybe you can save the trap that you got for another project and get the appropriate kind that you twist together-- it can save you a lot of grief later on if you do it that way. I don't know if it is a code rule to use that type or not.

You would need at least enough room to get your hands on the AAV and pull it up-- it all depends on how much space you have under the sink. I would probably leave at least 3" to 6" from the top of the AAV and the underside of the sink/counter (depending on placement). I personally have never used AAVs yet because they were prohibited by my state's plumbing code (up until the code was reverted to IPC 2012).

Makes sense, only question is...

What good would this trap do for me on a future project if it's no good on this one? Lol.
 
Makes sense, only question is...

What good would this trap do for me on a future project if it's no good on this one? Lol.
Good point. LOL. Maybe you can return the parts for a refund if you still have a receipt-- or you can use it for an art project or try to make a weird PVC figurine or something. Probably better to just return the stuff. I mentioned keeping it bc I am a hoarder. LOL.

But, IMO, you should definitely get the slip joint type p-trap for your kitchen sink in case food gets clogged in there that is larger than the little cleanout on the bottom of the glued trap and you need to clear it out. You can take the trap apart and use a side sprayer to spray out the inside of the bend with some force. This also allows you to make adjustments with the height and angles of the plumbing in case you make mistakes when trying to connect it in the first place. If you ever need to change out your garbage disposal to one that is higher or lower, you can use the slip joints to adjust the trap up or down to accommodate it.

On a side note, I found the reference to 6" and an AAV. AAV's terminating in an attic must be at least 6" above the insulation. http://www.summerville-home-inspect...ector-discusses-plumbing-traps-arms-and-vents

I will also add to keep in mind that short run 90 degree elbows are not allowed for use in drains-- you need long sweeps if you have any 90s. Not sure if you will have any 90s, but just thought I'd mention it.
 
Good point. LOL. Maybe you can return the parts for a refund if you still have a receipt-- or you can use it for an art project or try to make a weird PVC figurine or something. Probably better to just return the stuff. I mentioned keeping it bc I am a hoarder. LOL.

But, IMO, you should definitely get the slip joint type p-trap for your kitchen sink in case food gets clogged in there that is larger than the little cleanout on the bottom of the glued trap and you need to clear it out. You can take the trap apart and use a side sprayer to spray out the inside of the bend with some force. This also allows you to make adjustments with the height and angles of the plumbing in case you make mistakes when trying to connect it in the first place. If you ever need to change out your garbage disposal to one that is higher or lower, you can use the slip joints to adjust the trap up or down to accommodate it.

On a side note, I found the reference to 6" and an AAV. AAV's terminating in an attic must be at least 6" above the insulation. http://www.summerville-home-inspect...ector-discusses-plumbing-traps-arms-and-vents

I will also add to keep in mind that short run 90 degree elbows are not allowed for use in drains-- you need long sweeps if you have any 90s. Not sure if you will have any 90s, but just thought I'd mention it.

Okay.

I bought this garbage disposal installation kit. Comes with everything I need. Only problem is there are no clean out.

The P-Trap they sell with slip joints do not have cleanouts. Only the glue ones do.

Maybe I could add a clean out below the AAV?

Do slip joints require thread tape?
 

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