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TromboneAl · 03-30-2012, 07:21 PM

Note the pipe to which the arrow points:

Plumbing.jpg

Is that supposed to slope downward as it does in this case, or can it be level?

Because of the slope, the connections don't seem as secure, and a recent blockage caused some leakage.

Thanks.

73ss454 · 03-30-2012, 07:26 PM

I just looked at ours Al, and it's level.

REWahoo · 03-30-2012, 07:27 PM

Al, stick "under sink plumbing" in a Google Images search and you'll find many photos showing a similar set up with a level drain pipe.

NW-Bound · 03-30-2012, 07:27 PM

I have never seen a connection like that that was not level. And yes, the connection at the T will not be tight, if the horizontal pipe is not straight in-line with the inlet that the former slides into.

PS. Me think that if the food scrap needs the slope to drain properly, then it will get stuck at the J trap too! In other words, one needs to have enough flow to get the gunk going anyway.

Dimsumkid · 03-30-2012, 07:28 PM

Some slope is better than none. You can reduce the slope if you want. I'm concerned about the electrical outlet being so close to the pipe, it doesn't appear to be a GFCI outlet. I would change to a GFCI if it isn't one.

Brdofpray · 03-30-2012, 07:32 PM

Just checked my sink plumbing. It is level. As long as the pipe from the disposer joins the main drain above the trap, I don't think there will be a problem. I suppose somebody thought the slope will help drain the pulverized food stuffs from the disposer.

One caveat, I am not a plumber, but I have stayed at a Holiday Inn.

TromboneAl · 03-30-2012, 07:38 PM

OK, good, I will replace the pipe from the garbage disposal with a longer one so that all the joints are at right angles. I think I'll get new slip joints, too.

The outlet is tied in with the GFCI plug above the counter -- I just tested it and it is good -- thanks for the heads up.

Another question: the joint at the yellow arrow is not tight. That is, I can pull down and it slides down a little.

Plumbing.jpg

The nut on the compression fitting is tight, but the joint is not. Why would that be? I haven't noticed any leaking, but if there was a clog and water backed up to the sink, perhaps there would be.

NW-Bound · 03-30-2012, 07:43 PM

When the pipe enters the T inlet at an angle, the gap between the two pipes is no longer an annular space between two concentric circles.

That gap becomes elliptical in shape.

The soft nylon gasket ring or whatever it is called cannot seal an elliptical gap like that.

Telly · 03-30-2012, 10:07 PM

T-Al, did someone swap the disposal and the sink drain side for side? In other words, was the disposal on the right side sometime in the past?

The present configuration is sub-optimum. The disposal should be the one to get the straight-though shot to the trap, and the sink drain should get the side-inlet. This way, the solids and goo from the disposal head straight down to the trap, rather than coating a 90 and a horizontal or near-horizontal pipe, and then having the overshoot resistance of the side inlet.

It just looks wrong.

Telly · 03-30-2012, 10:12 PM

And what's with that funky shut-off valve for the hot water? One shut-off kills both the hot to the faucet, and the dishwasher? Looks cheap.

Or was this house pre-dishwasher, and someone did a quick conversion to add the function?

I don't think you should let me under your sink

Nords · 03-30-2012, 10:27 PM

Quote:

Originally Posted by Dimsumkid

Some slope is better than none. You can reduce the slope if you want. I'm concerned about the electrical outlet being so close to the pipe, it doesn't appear to be a GFCI outlet. I would change to a GFCI if it isn't one.

I've never seen a disposal slope, although waste piping is supposed to have a slight slope to encourage drainage. Even so, waste piping sloped joints still meet at 90-degree angles.

I've never met a GFCI outlet under a sink. While I can understand that it could be a recent addition to code, that sounds like too much of a good thing brought to you by the GFCI Manufacturer's Assn.

Quote:

Originally Posted by Telly

T-Al, did someone swap the disposal and the sink drain side for side? In other words, was the disposal on the right side sometime in the past?
It just looks wrong.

It sure looks like a disposal collar under the sink drain instead of a conventional sink drain, but maybe that's an older model of sink drain.

Quote:

Originally Posted by Telly

And what's with that funky shut-off valve for the hot water? One shut-off kills both the hot to the faucet, and the dishwasher? Looks cheap.

It sure is cheap, and one less joint to leak!

pb4uski · 03-31-2012, 04:37 AM

Waste pipes normally are sloped a minimum of 1/4" per foot IIRC, so your short run looks about right or perhaps pitched a bit more than that. Hard to tell from the pic. That said, for such a short run with 1 1/2" waste, I don't think it would do any harm if it were level.

Given the proximity of the electrical outlet to the water and waste pipes, I would change that outlet to a GFI unless there is already a GFI earlier in that circuit (which there may be depending on how that circuit is wired.

travelover · 03-31-2012, 05:08 AM

Quote:

Originally Posted by pb4uski

Waste pipes normally are sloped a minimum of 1/4" per foot IIRC, so your short run looks about right or perhaps pitched a bit more than that. Hard to tell from the pic. That said, for such a short run with 1 1/2" waste, I don't think it would do any harm if it were level.
...........

Don't forget that the garbage disposal is essentially a centrifugal pump, so there is no real need for a slope adjacent to it. I guess if you never ran the disposal, the whole section could end collecting sediment..........

TromboneAl · 03-31-2012, 09:01 AM

Quote:

Originally Posted by Telly

T-Al, did someone swap the disposal and the sink drain side for side? In other words, was the disposal on the right side sometime in the past?

The present configuration is sub-optimum. The disposal should be the one to get the straight-though shot to the trap, and the sink drain should get the side-inlet. This way, the solids and goo from the disposal head straight down to the trap, rather than coating a 90 and a horizontal or near-horizontal pipe, and then having the overshoot resistance of the side inlet.

It just looks wrong.

And what's with that funky shut-off valve for the hot water? One shut-off kills both the hot to the faucet, and the dishwasher? Looks cheap.

Or was this house pre-dishwasher, and someone did a quick conversion to add the function?

I don't think you should let me under your sink

No, it was never swapped while we lived here (house built in 96, we bought it in 99). I see your point, and the few times that we've had a problem, it's been with garbage disposal stuff at the 90 degree bend. I don't think I'll swap it, though because we almost never use the disposal.

I think the DW was put in originally.

Why does the double-duty shut-off seem cheap?

Thanks for the help.

TromboneAl · 03-31-2012, 09:02 AM

Quote:

Originally Posted by TromboneAl

Another question: the joint at the yellow arrow is not tight. That is, I can pull down and it slides down a little.

Attachment 13926

Answer: There was no compression washer in there.

ERD50 · 03-31-2012, 09:12 AM

Quote:

Originally Posted by TromboneAl

Answer: There was no compression washer in there.

Part of checking any plumbing like this is to stopper the sink(s) and fill them to the rim with water. Watch for leaks for a few minutes, then drain. It'll take a minute to drain down, and that joint would have been submerged for that time, and the leak due to lack of a washer would have shown.

Under more normal use, you might get a drip here and there from it., but you want it done right.

-ERD50