Kitchen Sink with 2 Traps

8/3/15

The house I moved into has the setup below (at the tinypic url at the bottom of this post) under the sink.

I have noticed that it is nearly impossible to get the garbage disposal side to drain properly and I am thinking it has to do with the 2 traps that are installed.

From my research (youtube videos and forums) it appears that 2 traps is a no-no in almost all cases. Additionally, I came across some information about venting, but I am unsure if my setup has, or requires, a vent. (there is a pipe running from the wall that has a black cover on it, but this does not appear to be a vent...maybe it was intended to be a vent, but it was never properly finished...or maybe someone thought they knew what they were doing and removed the vent there?).

I *think* what I need to do is:
1. Eliminate the trap connected to the disposal.
2. Run the disposal drain over to a new 'T' that would go below the tail-piece from the left sink (between the tail piece and the trap).
3. Run a new pipe from the single trap to the drain in the wall.
4. *maybe* replace the black cover with a vent?

Any help would be greatly appreciated!

[tinypic.com]

Some codes don't allow double traps on kitchen sinks. But to be honest, I find that double bowl kitchen sinks drain much faster when each bowl is separately trapped, and that is how I much prefer to do it.

The arrangement is lacking a vent, but I am thinking that you have another issue, perhaps a partial clog on the piping leading to the trap,

I prefer that setup it allows the 2nd compartment to work when the disposal is plugged.

If you want to single trap it, it is always better to put the disposal ell into the top of the tee and the tee on top of the trap. then connect the 2nd sink to the branch of the tee. this way the disposal discharge goes directly down into p-trap, not into the side of the tee which can splash back up into the 2nd sink.

cut off the left trap and keep the wye for a cleanout. maybe even flip it so the trap from disposal does straight to the santee and not make that extra jog through the wye.

just put a 90 going up on the capped line with a AAV (vent) or eliminate the 90 on the santee and go straight up with a AAV

MORE LEARNED FACTOIDS OF THE DAY

phishfood said:

Some codes don't allow double traps on kitchen sinks. But to be honest, I find that double bowl kitchen sinks drain much faster when each bowl is separately trapped, and that is how I much prefer to do it.

Click to expand...

Mr_David said:

If you want to single trap it, it is always better to put the disposal ell into the top of the tee and the tee on top of the trap. then connect the 2nd sink to the branch of the tee. this way the disposal discharge goes directly down into p-trap, not into the side of the tee which can splash back up into the 2nd sink.

Click to expand...

johnjh2o said:

I prefer that setup it allows the 2nd compartment to work when the disposal is plugged.

Click to expand...

This is the damnest forum! I learn something every time I come on here...

KULTULZ said:

This is the damnest forum! I learn something every time I come on here...

Click to expand...

Did you know human saliva has a boiling point 3 times greater than water?

looks like he has a 3'' stubbed up.

if so, i would utilize the 3'' and pipe it like the old island vents.

using the 3'' as a vent and eliminate the aav [cause i dont like em]

pipe the disposal into a continues waste, eliminate the disposal 90

andrew, you need to tie the dishwasher drain hose up to the bottom of the sink.

try and get it as high as you can, i tie them off to the sink clips with a piece of wire.

frodo said:

looks like he has a 3'' stubbed up.

if so, i would utilize the 3'' and pipe it like the old island vents.

using the 3'' as a vent and eliminate the aav

Click to expand...

I saw that 3" but failed to ignore it. FRODO is Right.

You're better off putting a 3 X 1.5 santee and a 3" cleanout on top of it.
using the over sized 3" as a wet vent

Matt30 said:

Did you know human saliva has a boiling point 3 times greater than water?

Click to expand...

...I did not know that..

Of course I also don't have one of them back East fancy educations either...

Now let me see if I have all of this stuff written down...

1) Hot is on the left...

2) Cold is on the right...

3) Shiat flows downhill...

4) Payday is on Fri...

5) Try not to bite nails

6) Say no to plumbers crack...

7) Human saliva has a boiling point 3 times greater than water...

Anything else I should know?

KULTULZ said:

...I did not know that..

Of course I also don't have one of them back East fancy educations either...

Now let me see if I have all of this stuff written down...

1) Hot is on the left...

2) Cold is on the right...

3) Shiat flows downhill...

4) Payday is on Fri...

5) Try not to bite nails

6) Say no to plumbers crack...

7) Human saliva has a boiling point 3 times greater than water...

Anything else I should know?

Click to expand...

you forgot one of the main ones.

Boss is an Azz Hole

and old yellow # five tastes like mustard, on bologna

frodo said:

you forgot one of the main ones.

Boss is an Azz Hole

and old yellow # five tastes like mustard, on bologna

Click to expand...

...hmmph...

Darn if I didn't...

Boy,

This test has a whole lot to remember...

the real test, they put you in front of a 4' tall , 2 story doll house. with a bunch of plastic fittings and a box of straws

the test is 8 hours long. 1/2 written 1/2 hands on


what % of a 10' vertical wall do you use to calculate for the roof drain size ?

10%
25%
50%
100%

how far, is the allowable length of a 2'' indirect drain before venting
3'
5'
10'
15'

LOL

frodo said:

the real test, they put you in front of a 4' tall , 2 story doll house. with a bunch of plastic fittings and a box of straws

the test is 8 hours long. 1/2 written 1/2 hands on


what % of a 10' vertical wall do you use to calculate for the roof drain size ?

10%
25%
50%
100%

how far, is the allowable length of a 2'' indirect drain before venting
3'
5'
10'
15'

LOL

Click to expand...

Without looking it up, and going by IPC.

#1 is 50%

#2 I think you worded the question wrong. I think it should be allowable length before it needs a trap, and I THINK the answer is 5'

phishfood said:

Without looking it up, and going by IPC.

#1 is 50%

#2 I think you worded the question wrong. I think it should be allowable length before it needs a trap, and I THINK the answer is 5'

Click to expand...

upc is 100% i remember that question,,it was asked twice
only ? that was double asked


i did indeed word it wrong, thanks,