: In NYC not more then 2 feet.

: But many of the country plumbing codes allow a much greater distance

: If your using the micky mouse codes like the SBCCI then almost anything is legal .

: The SPC is another joke.

: More then half these codes do not even address a suds pressure zone so venting in these codes is also lacking in quality design.

: Check local codes. The closer to the fixture the better.

: The standard plumbing code (a joke) table 906.1
: I would assume they are saying 10 feet.

You can't be serious! 2' is the maximum trap arm you can run with 3" pipe????? What possible justification could there be for this?
The closer the better is not necessarily true. The main purpose of a vent is to equalize the pressure in the drainage system, so that p-traps do not siphon out. UPC has the following limits on trap arm lengths1-1/2" 3-1/2' 2" 5' 3" 6'
4" 10' (except for toilets that have to be within 6' regardless of the size pipe).
Deb
The Pipewench