PVC Schedule 40 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

Schedule 40 PVC is rigid polyvinyl chloride pipe made to ASTM D1785, the standard that covers PVC pipe in Schedules 40, 80 and 120 for pressure use.^[2] It is the white pipe most often seen in US hardware aisles, and one maker's white Schedule 40 is dual-marked to ASTM D2665 so the same pipe also serves drain, waste and vent (DWV) lines.^[1]

"Schedule" names a wall thickness tied to the outside diameter of iron pipe sizes. Schedule 40 and PVC Schedule 80 pipe share an outside diameter at each size; Schedule 80 has the thicker wall.^[1][3]

1 Sizes and pressure ratings

Pressure ratings for PVC are stated for water at 73°F, and they fall as the pipe gets larger because the wall does not thicken in step with the diameter.^[1] The table lists one maker's figures for common house sizes; the outside diameter matches the nominal size only loosely, as explained under nominal pipe size.

The same maker sets 140°F as the top operating temperature for its PVC pressure systems.^[2] Above 73°F the rating is multiplied by a correction factor: 0.62 at 100°F, 0.40 at 120°F and 0.22 at 140°F.^[1] A 2 in pipe rated 280 psi at 73°F is listed at 62 psi at 140°F.^[1] Fittings, valves and unions carry their own ratings, and a system is only as strong as its weakest part.^[1]

2 Uses in a house

The maker lists typical Schedule 40 pressure uses as carrying drinking water up to a building, irrigation and sprinkler lines, and HVAC condensate drains; for drinking water inside a building it points to CPVC pipe instead.^[1] Where PVC may be used for water service or distribution is set by the plumbing code a city or state adopts, and local amendments vary, so the building department has the final word. Because of the 140°F limit, Schedule 40 PVC is not a hot-water pipe.^[2]

Dual-marked pipe is also used for drains and vents.^[1] Lighter cellular-core pipe of the same outside diameter is covered under PVC DWV and foam-core pipe.

3 Joining

Schedule 40 PVC is joined by solvent-weld joints: a primer to ASTM F656 and a PVC cement to ASTM D2564, with the cement body chosen by pipe size.^[1] The maker does not recommend cutting threads in any thermoplastic pipe other than CPVC and PVC Schedule 80, so threaded connections to Schedule 40 runs are made with molded threaded adapters.^[1] Supply houses stock pipe, fittings, primer and cement by size; PlumbingSupplyAndMore's PVC pipe category (PlumbingSupplyAndMore has the same owners as this reference) is one example.

4 Sunlight and outdoor runs

Sunlight changes PVC only at the surface, to a depth of about 0.001 to 0.003 in, fading the color and lowering impact strength while leaving pressure rating and stiffness largely unaffected.^[1] An opaque shield or burial blocks the effect.^[1] For pipe left above ground, the maker's usual protection is latex (water-based) paint on a clean, dry surface; petroleum-based paint should not be used because it will not bond.^[1] Radiant heat from the sun can raise the surface temperature of pipe by 50°F or more, which can push a line past its temperature limit or derated pressure.^[1] More on outdoor exposure is under sunlight and UV limits.