I am installing a dryer vent (using rigid aluminum vent). The vent will be running along the same path as a 1.5" ABS pipe (which is used as drain vent, so no water flows through it).
Would it be a problem if the dryer vent touches the ABS pipe?
Residential clothes dryers typically vent at a temperature of around 130°-165°F (54°-74°C). Wikipedia gives the glass transition temperature (colloquially the melting point) of ABS as 221°F (105°C). Even assuming that you get a perfect heat transfer, you'll be fine.