# Flat  Venting



## north star (Jun 1, 2018)

*~ & ~*

I have a set of plans with a 4" horizontal drain to 4" horizontal drain
connection with a 45 degree wye fitting and then a 1/8th fitting farther
upstream.......Both of the 4" drain lines are for solids & liquids.......The
heel inlet of the 4" wye fitting connects to an existing 4" dry vent....The
term I am thinking of is "flat venting".

In looking at the proposed design of this connection wye fitting, I am
thinking that the solids entering the existing 4" drain line "could"
potentially block the dry vent......I have always been taught that these
types of "horizontal drain-to-horizontal drain fitting" connections
should have the wye fitting turned upward ( full vertical position ), so
that the drain line solids enter the downstream horizontal drain line
from the top rather than the side.

*QUESTION # 1:*  Does any of this rambling make sense to ya'll ?
*QUESTION # 2:*  Is there language in the `06, 09 or `12 IPC's, that
require the solids to enter from the top of the horizontal drain line
rather than from the side ?
*QUESTION # 3:*  Haven't we had similar discussions on this Forum
before regarding "flat venting' ?

Thanks !

*~ & ~*


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## steveray (Jun 1, 2018)

Vent connection has to be above the centerline of the pipe....For a dry vent. I guess we just ignore when it is a wet vent as in theory the wet waste will clear the vent, or the waste will plug and you will clear the vent....

905.3 Vent connection to drainage system. Every dry vent
connecting to a horizontal drain shall connect above the centerline
of the horizontal drain pipe.


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## north star (Jun 1, 2018)

*% ~ % ~ %*

Much Thanks ***steveray*** !  

*% ~ % ~ %*


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