With Ductile iron pipe (DI pipe), typical service taps can be installed directly into the wall of the pipe, which is called “direct tapping.” The ability to use direct tapping eliminates the need for tapping saddles. And the ease at which DI pipe can be "hot tapped" helps avoid the issue of unhappy consumers because their service and pressure are not impacted by the addition of a new tap. The waterworks community frequently asks us, “How big of a tap will DI pipe allow?” The simple, most conservative response, not having interrogated the user as to their DI pipeline particulars, would be as follows:
3-inch and 4-inch pipe ─ ¾ inch
6-inch through 10-inch pipe ─ 1 inch
12-inch thorough 16-inch pipe ─ 1 ¼ inch
24-inch and Up pipe ─ 2 inch
This would be the most understated response to the minimum tap size, based on pipe size only.
