PVC DWV and foam-core pipe

Entry in Drain pipe and retired pipe · Updated October 29, 2026 · Written by the Know Your Pipes editors from the sources listed under References

PVC DWV pipe is white polyvinyl chloride pipe for drain, waste and vent (DWV) lines, made either as solid-wall pipe to ASTM D2665 or as cellular-core ("foam-core") pipe to ASTM F891.^[1] Both are Schedule 40 outside diameters and take the same Schedule 40 DWV fittings.^[1]

ASTM D2665 covers PVC pipe and fittings for the drainage and venting of sewage and certain other liquid wastes.^[2] Black drain pipe of the same sizes is ABS pipe. Larger sewer mains may instead be thinner PVC sewer pipe to ASTM D3034, which is made for nonpressure drainage of sewage and surface water.^[3]

1 Solid wall and foam core

Solid-wall pipe is PVC through the whole wall.^[1] Cellular-core pipe is co-extruded: a thin solid inner layer and a thin solid outer layer with a foamed layer between them.^[1] It has exactly the same dimensions as solid wall, but it is lighter and costs less.^[1]

Charlotte Pipe's solid-wall Schedule 40 is "dual marked" to ASTM D1785 and D2665, so it meets both the pressure and drainage standards.^[1] That dual marking is why the same white pipe appears as PVC Schedule 40 pipe in pressure tables.^[1] Foam core carries no pressure rating at all; this maker prints "Not for Pressure" on every piece.^[1]

2 Noise, stiffness and burial

Noise in a drain line follows density. Cast iron is by far the quietest, and solid-wall PVC is somewhat less noisy than PVC or ABS foam core.^[1] Both kinds can be buried at most depths in common soils, but solid wall has the higher pipe stiffness and resists mechanical damage better.^[1] ASTM F628 and F891 limit bedding aggregate around the pipe to 1/2 in for angular stone and 3/4 in for rounded stone.^[1]

The maker notes that many designers accept foam core on houses and light commercial work but call for solid-wall PVC or cast iron drain pipe in schools, restaurants and hospitals.^[1]

3 Code status and use

According to the maker, the UPC, the IPC and the National Standard Plumbing Code all allow these PVC systems for sanitary and storm drainage above and below grade, without separating residential from commercial use, and it says the pipe can go in most locations other than return-air plenums.^[1] Local amendments vary, so the building department decides. Pipe is joined with PVC primer and cement by solvent-weld joints, and direction changes use drainage-pattern fittings such as the sanitary tee and wye.^[1]