Cast iron short sweep horz-horz connection exception (UPC)

I have a quick reference flip book that indicates there is an exception allowing CI short sweep 90s to be used on horizontal to horizontal drain line connections for 2" and smaller pipe. I cannot find this in the UPC code itself. Is this exception well-known and can anyone reference or quote the code supporting it?

NEver heard of it. Might by apocryphal.

I can't find any exceptions, the book I have only allows long sweeps, short sweeps but no 1/4 bends.

The only time you could flip them horizontal would be on a trap arm.

shacko said:

I can't find any exceptions, the book I have only allows long sweeps, short sweeps but no 1/4 bends.

Click to expand...

Well, that's the thing... are you saying you see UPC approving short sweep for 90-deg turn in horizontal run? I'm going from memory as my code book is at jobsite... but I thought it indicated only a Combo-wye or "equivalent sweep"; when I compared the short sweet (cast iron keep in mind) to the combo the sweep was noticably less.

Oops... looks like I cross-posted w/ Terry... that sounds pretty definitive (and not in a good way

More Generally: CI vs ABS

Maybe I can broaden my question, because I don't understand why the dims on CI and ABS are so different for the same sized pipe.

Below is a set of drawings taken from CharlottePipe.com showing dims for CI on the left and ABS on the right. Some points of note: the CI Short Sweep is larger than the ABS Long Sweep (compare CI-SS 'D' to ABS-LS 'B'); the CI 1/4 Bend is approximately the size of the ABS Long Sweep (compare CI-QB 'D' to ABS-LS 'B'); the ABS Combo is a much larger turn than the ABS Long Sweep (compare ABS-CB 'A' to ABS-LS 'A').

So, based on this it would seem fair for CI Short Sweep to be used in places that ABS Long Sweep can be used. For that matter, given the dims for CI Quarter Bend vs. ABS Long Sweep it'd seem like that could be used in the same places (as a practical point, not by code). So... what's going on here? Can someone explain the logic of all of this?

quote; Can someone explain the logic of all of this?

You are asking an engineer or a bureaucrat to be "LOGICAL"?

hj said:

You are asking an engineer or a bureaucrat to be "LOGICAL"?

Click to expand...

I guess I always expect the best from people.

I only dug out all of this info b/c I'd gone to HD and bought a bunch of 2" ABS and when I went to grab an ABS LS-90 for a vert to horz transition.... I kept digging and digging in the pile of parts looking for an 'appropriately' sized piece w/ a sweep about that of the Combo-wye.... when I couldn't find that I decided I'd failed to buy LS-90's... until I looked up the specs and found I had them all right, but still they seemed all wrong.

So essentially ABS has three sizes for 90's: the vent-90, the 1/4 bend and the LS-90. Correct? And the 1/4 bend can only be used for horiz-to-vert transitions?