Totally Horizontal T in venting - not as easy as it look.

Hello All,

I'm hoping for some insight into what looks easy, but has been impossible to find information on.



On one wall of my home, at opposite ends of the wall, I have two (dry) vents coming up to (near) ceiling height. On the opposite wall, in the middle of the building is the 3" vent stack they need to get to.
Pictured here (rough sketch just to show layout and relationship of the vents)


Original thought: Run the two vents along the wall to a T in the middle, which would then go across to the roof vent. But, no.. what sort of T? Santees and Wyes don't really make sense.
Do i have to do something odd with joining one of the vents into the bottom of the other then back and around?
Along these lines:


Other suggestions?

Thanks,

g.wagner

You could use a twin ell.

http://www.cleanwatercomponents.com/node/453

john

Using a santee makes a great deal of sense, since it is perfectly acceptable anywhere I know of, and it costs 1/5 as much as a vent tee, typically.

It's a vent.
A Santee would be fine.

Not necessary to offset it as you show. It is a vent, no fluid waste, and since the volume and velocity of air flow is minor compared to the actual capacity of the pipe, the "sweep" of fittings is not so critical. A regular vent tee, keeping all three pipes on the same plane, would be my choice. Be careful to have a little slope, with no valleys in the runs,

Air does not flow the same way as water so a regular sanitary tee is acceptable, except when you have an inspector who only knows "what" is in the book, but not "why". Then you would use a twin elbow, or a vent tee which is not directional. There are other possible "creative" solutions in the horizontal plane, but they all require more fittings than you really need.

Thanks all, very much appreciated. Slightly reassuring that the logical way is actually correct. I was concerned that, since any water that does get into the vent must flow back to the drain, there was some odd requirement that it had to predictably flow to a specific drain, not just any drain. Too much time on computers thinking things need to be deterministic, I guess.

Cheers,

g.wagner

nocluetoo said:

I was concerned that, since any water that does get into the vent must flow back to the drain, there was some odd requirement that it had to predictably flow to a specific drain, not just any drain. Too much time on computers thinking things need to be deterministic, I guess.

Click to expand...

You sound like a fellow engineer ... always thinking too much

Maybe like the one who ordered a bearing from a piece of 3/4" brass rod with a 7/8" hole bored down the middle, then wondered why he got a box of shavings.