Systems & CodeQuestion 48 of 110
An indirect waste pipe has an effective outlet opening of 3/4 in. The required air gap above the receptor flood-level rim is two times the effective opening. What is the minimum air gap?
a.3/4 in
b.1 in
c.3 in
d.1-1/2 in
Explanation
Air gap = 2 x effective opening = 2 x 3/4 in = 1-1/2 in. The two-times rule sets the vertical separation that prevents waste from siphoning back into the indirect-wasted equipment. Near a wall the multiplier increases to three times the opening, which would give 2-1/4 in here.
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