Closet Bend Details and Code References

[wwhitney]

Hello,

To my current understanding, a "closet bend" is a sharper than typical bend allowed for use directly under a WC to permit horizontal WC drains to be run within a fairly shallow floor framing system. So a few questions:

1) If you have extra height available for a medium or long turn quarter bend, is there any reason not to use one?

2) Is there a code section (UPC and/or IPC) that explicitly allows the sharper than typical bend directly under a WC?

3) Looking at Charlotte's plastic and cast iron catalog, the interior angle on closet bends is quite sharp, basically square (see below for pictures). So does that mean in plastic, a regular vent 90 may be used as a closet bend?

Thanks,
Wayne

Charlotte SV200 Service Weight Cast Iron Closet Bend

Charlotte 330 Hub x Spigot 3 x 4 Closet Bend

Charlotte 331 Vent Ell

 

[James Henry]

I know I'm not the only one who knows this but I'll chime in. #1. Sweeps are commonly use under toilets in a crawl space to avoid the joist's.
#2. The drainage section of the code prohibits the the use of a 1/4 bend to be used from vertical to horizontal. they are not going to repeat themselves for every plumbing situation, that's why they keep saying, " In accordance with section …"
#3. If you compare dimension B. on charlotte 330 and dimension A on charlotte 331 you will notice the closet bend is wider.

 

[Sponsor]

 

[wwhitney]

Hi James,

Thanks for your responses. Some followup:

1) I think my question wasn't clear, I meant is there any reason not to use a long turn 90 right below a WC, if you have the room? Pretty sure the answer is no.

3) Thank you for prompting me to take a closer look at the numbers, and not to focus on the seeming square inside corner on the drawings. Charlottle 329 Hub x Hub 3x4 Reducing Closet Bend has an "A" measurement of ~ 3 1/16" (depending on PVC vs ABS). And a regular 3" quarter bend has a radius of 3 1/16". So in plastic, the closet bend radius seems to be very close to the quarter bend radius. Which makes it clear the vent 90 is certainly not allowed.

2) So that's my confusion, a quarter bend is prohibited for turning from vertical to horizontal, except it seems to be allowed for a closet bend. Is there some specific language I'm missing that allows that directly under a WC? I'll check again.

Cheers, Wayne

 

[James Henry]

1) I think my question wasn't clear, I meant is there any reason not to use a long turn 90 right below a WC, if you have the room?

I answered the question with an example. As far as using a 1/4 bend, the orientation of it is against code but you may get away with it in some places. I'm not the almighty authority I just know how to interpret the code.

 

[hj]

1. If there is room there is no reason NOT to use a bend, but in 65 years or plumbing, I have ALWAYS used either a 4" closet bend or a 3" x 4" closet bend. NEVER a 3" or 4" 90 elbow.

 

[Jeff H Young]

Residential plumbers running plastic use 4 x3 plastic closet bends all the time but I've never seen a 4x4 hub x hub plastic closet bend. I cant imagine such a fitting having a sweep not tighter than a medium sweep