Question

dishwashers in some areas
require an air gap fitting
must drain directly into a stack
cannot drain into a waste disposal
cannot discharge into a tailpiece of a sink
must discharge into a trap arm upstream of the vent
question 44
horizontal cast iron piping is prone to
splits on the top
noise transmission
sags when supported at 3 foot intervals
combustibility
rusting after 15 years

Explanation:

In many plumbing - code areas, dishwashers require an air - gap fitting to prevent back - siphonage of contaminated water into the potable water supply. Horizontal cast - iron piping is known for its high sound - transmission properties due to its density and rigidity.

Answer:

1. require an air gap fitting
2. noise transmission