I am replacing my kitchen countertop and want to install an undermount sink which is also deeper than the current one. So I have to lower the garbage disposer. currently there is a s-trap connected to the disposer and the s-trap goes into a horizontal pipe. Can I use an L-shaped pipe between the s-trap and the horizontal pipe to lower the disposer by 3-4 inches? Would you recommend any other maximum height of the L-pipe? Any help would be appreciated. thanks.
kitchen sink/disposer plumbing
- Thread starter PJain
- Start date
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...Not much use for them here.Sorry 
EH? Well mine works fine thankyou very much. Sounds like the grot gobbler and the sink each have their own S trap, and then the pipe goes to a horizontal. That's absolutely fine. As long as the pipes which aren't part of the trap itself are all downhill. If you have to go UP with your L shaped pipe to the horizontal one, you'll be making another trap which is, er, not ideal!
Chris, thanks for your reply. I checked again and I was mistaken about the s-trap. Actually the horizontal pipe coming out from the wall has a p-shaped pipe from which another pipe comes and goes up a few inches to connect to the garbage disposer. what do you think is the best way to lower the disposer?
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It's best if the WD and the sink have their own traps, doesn't matter which type, to reduce the amount of pipe above the water line in the trap(s). This is to reduce the smells which come up.
After the trap you'd just use whatever you need to get to the common exit.
After the trap you'd just use whatever you need to get to the common exit.
PJ, what state are you in? The Uniform Plumbing Code does not allow S-traps. So presuming a P-trap:
when your sink is lowered the garbage disposal will lower by the same amount, hence your trap arm will find its own outlet level.
The trap arm should run into the wall and be picked up by the sanitary tee in the waste and vent pipe.
From your description you will have to open up the wall and cap the old arrangement.
Come back if the above suggestion is not feasible.
when your sink is lowered the garbage disposal will lower by the same amount, hence your trap arm will find its own outlet level.
The trap arm should run into the wall and be picked up by the sanitary tee in the waste and vent pipe.
From your description you will have to open up the wall and cap the old arrangement.
Come back if the above suggestion is not feasible.
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