Did you size the vent the same as the largest fixture drain size requirement? i.e. floor drain, lab sink….?
Floor drains are counted as 3″, not 4″ …..which will size your vent at 3″ for the vent off the dilution pit along with the VTR.
There was a code course up here in my area that taught 4″ and 4 DFU’s on that floor drain and I still believe that to be true; it’s a commercial floor drain……commercial application, bottom line. But…..then they state the only requirement on that gammut is manufactured floor drains.
It’s all confusing.
They now have master’s testing every thursday down there in frankfort now……not once a month anymore. DUNBAR2007-09-20 04:28:52
I had the Vent on the DT as a 4″ and it shoulda only been a 3″. . .the FD’s on the waste line had 5′ arms, that’s all you had to go by and i sized them a 3″, when i think they shoulda been a 2″. . .i was half asleep when i took it. . .didn’t get much rest the night before. .