Plastic vent pipe types listed below have been certified by the American Gas Association for use in furnaces classified as Category 4.

These particular types of furnaces use positive pressure vent systems (exhaust gas temperature less than 1400F above the dew point temperature) and are always equipped with an induced draft motor which removes exhaust gases from the appliance and discharges them to exterior.

The dewpoint temperature is the temperature at which the air can now longer hold all of its water vapor, and some of the water vapor must condense into liquid water. (definition by weatherquestions.com)

High efficiency furnace PVC vent pipe types and specificationsProper installation of the vent system is essential for the condensing furnace (that’s another name for category 4 type furnace) to achieve maximum efficiency and to drain condensate efficiently from the system.

Make sure that your  installation complies with National, State and Local codes. Some of the furnace installation guides may be available online or obtained directly from the manufacturer.

There are 3 plastic types of pipes certified by the American Gas Association for use in high efficiency, condensing, category 4 furnaces: PVC, CPVC, and ABS

PVC  pipe

ASTM Standard Type of the Pipe max Allowable Temp Marking on pipe surface
F891 Cellular Core 158o ASTM F891
D2665 DWV Pipe ASTM D2665
D1785 SCH 40, 80, 120 ASTM D1785
D2241 SDR Series ASTM D2241

CPVC Pipe

ASTM Standard Type of the Pipe max Allowable Temp Marking on pipe surface
D2846 CPVC 41 212o ASTM D2846
F441 SCH 40, 80 ASTM  F441
F442 SDR Series ASTM F442

ABS Pipe

ASTM Standard Type of the Pipe max Allowable Temp Marking on pipe surface
D2661 SCH 40 DWV 180o ASTM D2661
F628 SCH 40 DWV Cellular Core ASTM  F628441