New deeper kitchen sink causes DWV problems


  #1  
Old 12-01-10, 08:13 PM
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New deeper kitchen sink causes DWV problems

Installed a new deeper kitchen sink (went from 7" to 9") and very slightly underestimated the difference in the DWV piping. I thought I wasn't going to have a problem.

I'm not way off, if I didn't have a dishwasher to drain everything actually would be fine, but I'm about 1/2" off in getting a dishwasher tailpiece to fit. Please see the pictures.

I'm sure the right answer is to open the wall and lower the drain point on the stack, but is there an alternative? Either lowering the p-trap slightly or connecting the dishwasher drain elsewhere? I've already got the shortest sink basket I could find and could not find a dishwasher tailpiece with a higher wye. Do they make a tailpiece with a higher wye?

Thanks in advance.



 

Last edited by jogordo; 12-01-10 at 08:51 PM.
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Old 12-02-10, 10:48 AM
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Usually the brass DW tail pieces are higher and that may work. Also that strainer is very long. Looks like for na cast iron sink. I most certainly know you can get a shorter one. If all else fails then put a regular tailpiece there and use the clean out there and pipe a second trap with a riser. Kind of like your washing machine drain.

Mike NJ
 
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Old 12-02-10, 03:15 PM
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You have a couple of options, you can use a low inlet trap which may be hard to find.

you also can get a pvc return bend and make your own trap, I think this the easy way to go, just add a trap adaptor to it

NIBCO.com - PVC DWV Fittings (4800 Series)
 
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Old 12-02-10, 09:18 PM
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It may not be code, and it may not be elegant, but as an engineer in my spare time I can't identify any reason why the following is necessarily a bad idea. The connections are robust and, if anything, a deeper trap provides a better seal. The only issue I can think of is that the velocity through the pipe is slowed a tad which could affect self-cleaning but is there any scientific problem with a small increase in the depth of the trap?



Basically, I replaced the p-trap j-bend with a "repair j-bend" (female coupling on the end that ties to the arm) obtained from HD and used a slip joint coupling threaded in between the two. Absolutely no leaks and the piping is tight.

I'd like to make this temporary (really needed to get the sink working again) and still try a low-inlet trap or a sch 40 trap (which would save me a little bit of height as noted above). Once I settle in on the permanent solution I'll replace the plastic tailpieces with brass.
 
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Old 12-03-10, 02:05 PM
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By increasing the seal of the trap you also increase the chance of having a stoppage in your line, you didn't need to do it to the right trap. I would get it out of there as soon as I could, like I said in my previous post use a return bend and build your own and you should have plenty of room.
 
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Old 12-03-10, 02:41 PM
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Looks good. yeah the back trap you can hook up normal. That back nut behind the C/O looks cross threaded. How do you know it dont leak I see no waterlines hooked up!!!! LOL Just kidding.

The problems with this setup is you have more water in the trap that is filled to and above the nuts. If it was piped correctly the trap water would be below the two nuts. If memory serves me right we would hard trap these in this situation. I dont believe what you have is code. I could be wrong and I would not do this. Whoever came behind me and saw this would laugh at me. I think hard trapping would suffice for code.


Another thing you could do is a garbage disposal. The D/W port is part of the G/D and I believe the outlets are higher on the disposal to meet your trap height.

This would be better One Trap just to give you ideas:::

http://rds.yahoo.com/_ylt=A0WTefjIYf...itchdrain1.jpg

You can pipe a third hard trap from the c/o and use this for the DW. Then you can fix all that.

http://www.metrosupply.ca/thumbnail/...326667/215/275



Mike NJ
 
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Old 12-04-10, 08:27 AM
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This should do, if I can find it (low-inlet trap):

http://www.keeneymfg.com/cad_drawing...PDF?1260481939

Gives ~ 2" pipe insertion if the drawing is accurate. The inlet to the pipe sits between 3/4 and 1 inch lower than a standard trap. No re-work of my existing setup needed.

As compared to the typical trap:

http://www.keeneymfg.com/cad_drawing...pdf?1260481915
 
 

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