Kitchen drain line pitch problem

[Mervmaster]

I've installed a new countertop and sink. The new sink is slightly deeper than the old, causing my p trap outlet to be at or below the level of my waste line port.

I have access to the crawlspace, and I'd like to send the kitchen drain line through the floor, and have it join the vent line a few feet after it does now.

This will cause the waste line to run vertically through the floor after the p trap.

Is there any reason a shouldn't have the line running vertically?

I know 1/4" per foot is the correct pitch, and more than 1/2"-45° is bad.

Is 90° acceptable? Will is cause a siphon, or a flooded condition at the elbow where vertical turns back to horizontal?

Thanks. I can't find anywhere that says this is OK, nor anything that says it isn't.

 

[frodo]

this guy just lowered his drain, the correct way
http://www.plumbingforums.com/forum/showthread.php?t=11595

it is called an "S" trap and it is illegal

WHY? the water will siphon out of the trap and sewer gas will make your house smell like someone farted

post a picture, lets see what we can think of

 

[Mervmaster]

this guy just lowered his drain, the correct way
http://www.plumbingforums.com/forum/showthread.php?t=11595

it is called an "S" trap and it is illegal

WHY? the water will siphon out of the trap and sewer gas will make your house smell like someone farted

post a picture, lets see what we can think of

So it's not an s trap exactly.


The existing drain port is fully an inch higher than my p trap output. So that's out.

Below is what I propose to do(roughly)

Thanks for looking

 

[Matt30]

That is still an s trap. You have no vent.

 

[frodo]

That Is An S trap

901.2.1 Venting required. Every trap and trapped fixture shall be vented in accordance with one of the venting methods specified in this chapter

1002.3 Prohibited traps. The following types of traps are prohibited :
Traps that depend on moving parts to maintain the seal.
Bell traps.
Crown-vented traps.
Traps not integral with a fixture and that depend on interior partitions for the seal, except those traps constructed of an approved material that is resistant to corrosion and degradation.
"S" traps.
Drum traps.

 

[Mervmaster]

That Is An S trap

901.2.1 Venting required. Every trap and trapped fixture shall be vented in accordance with one of the venting methods specified in this chapter

1002.3 Prohibited traps. The following types of traps are prohibited :
Traps that depend on moving parts to maintain the seal.
Bell traps.
Crown-vented traps.
Traps not integral with a fixture and that depend on interior partitions for the seal, except those traps constructed of an approved material that is resistant to corrosion and degradation.
"S" traps.
Drum traps.

Ok , I get that it looks like an s, but there is a vent less than 5 feet from where it would join the drain line in the crawlspace. Still no good?

I must be thinking about it wrong.

 

[Matt30]

By having it piped like an s trap, you choke off the vent you already had.No good. You are venting the trap, not the drain.

To make that better, you can use an air admittance valve. To make it correct, refer to the link frodo posted.

 

[Mr_David]

The vent has to connect above the weir of the trap.
anything after the last 90 is useless.
Even if you connected the vent 2" below your last 90. USELESS!!

 

[Mr_David]

You can use an all glue p-trap and replace the street 90 with a regular 90 and increase the depth od the weir to 4". Not Ideal but a better alternative.

SEE NOTE IN PICTURE ABOVE

 

[Mervmaster]

Oh you guys are fantastic. Thanks so much for your attention- you've saved me from a huge inspection hassle.