connecting branch drains to trunk?

Old 08-05-16, 09:02 PM
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connecting branch drains to trunk?

I am repiping my DWV with a 3" ABS trunk. Should the drain lines from my sinks, washer, toilets, etc. attach on the side of the 3" trunk, the top of the trunk, or on a 45 degree angle into the trunk? I was planning on using wyes or long sweeps on the side of the trunk as long as the fixture drains are 1/4" over a foot slope. What is correct? I was also told a DWV pipe can be between 45 and 90 degrees, but no less than 45. Is this correct? thanks!
Old 08-08-16, 10:06 AM
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It doesn't matter if drains connect horizontal, vertical or somewhere in between on a horizontal main drain. You'll need to use wyes (or combo wyes) for all the connections. Sanitary tees are allowed only when going from horizontal to vertical.

I don't know what code specifically states as a maximum angle. I've read that you should always keep them vertical or horizontal (with the 1/4" fall). Between that you run the risk of the water moving faster than the solid waste. But I'm not sure if it's specifically against code or just a recommendation.

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