PipeData

Schedule 140 Pipe Dimensions

Wall thickness, bore and plain-end weight for all 9 sizes ASME B36.10M publishes in schedule 140, NPS 8 through NPS 24.

Schedule
Schedule 140
Sizes published
9 (NPS 8 to NPS 24)
Thinnest wall
0.812 in (20.6 mm) at NPS 8
Thickest wall
2.062 in (52.4 mm) at NPS 24
Standard
ASME B36.10M

Where schedule 140 is used

Schedule 140 is a heavy wall published only in the larger sizes, used in high-pressure steam and feed water piping and normally made to order.

Pipe wall thickness to scale, Schedule 140Pipe cross-sections drawn to scale at the same outside diameter so the wall thicknesses can be compared. NPS 8: 0.812 in wall on 8.625 in OD; NPS 16: 1.438 in wall on 16.000 in OD; NPS 24: 2.062 in wall on 24.000 in ODNPS 80.812 in wall on 8.625 in ODNPS 161.438 in wall on 16.000 in ODNPS 242.062 in wall on 24.000 in OD
Schedule 140 in three sizes, each drawn to its own scale. The sections are drawn at the same width so that the wall can be compared with the diameter it belongs to. The wall gets thicker as the size goes up, but it takes up a smaller share of the pipe.

Schedule 140 in every size

Dimensions are given in inches, with the millimetre equivalent beneath in grey.

ASME B36.10M schedule 140 dimensions.
SizeDNOutside diameterWall thicknessInside diameterWeight, emptyWater (US gal/ft)This size
NPS 8DN 2008.625219.07 mm0.81220.62 mm7.001177.83 mm67.82100.93 kg/m2.000all schedules →
NPS 10DN 25010.750273.05 mm1.00025.40 mm8.750222.25 mm104.23155.11 kg/m3.124all schedules →
NPS 12DN 30012.750323.85 mm1.12528.57 mm10.500266.70 mm139.81208.05 kg/m4.498all schedules →
NPS 14DN 35014.000355.60 mm1.25031.75 mm11.500292.10 mm170.37253.54 kg/m5.396all schedules →
NPS 16DN 40016.000406.40 mm1.43836.53 mm13.124333.35 mm223.85333.13 kg/m7.027all schedules →
NPS 18DN 45018.000457.20 mm1.56239.67 mm14.876377.85 mm274.48408.47 kg/m9.029all schedules →
NPS 20DN 50020.000508.00 mm1.75044.45 mm16.500419.10 mm341.41508.08 kg/m11.108all schedules →
NPS 22DN 55022.000558.80 mm1.87547.62 mm18.250463.55 mm403.38600.29 kg/m13.589all schedules →
NPS 24DN 60024.000609.60 mm2.06252.37 mm19.876504.85 mm483.57719.64 kg/m16.118all schedules →

Weight is plain-end carbon steel, w = 10.69 × t × (OD − t) lb/ft.

How the wall changes with size

The wall in schedule 140 is 0.812 in (20.6 mm) at NPS 8 and 2.062 in (52.4 mm) at NPS 24. Measured against the pipe it belongs to, that is 9.4% of the outside diameter at the small end and 8.6% at the large end, so the wall does not keep pace with the diameter. The pressure the pipe will hold moves the same way. On the basis used throughout this site (ASME B31.3, S = 20,000 psi, nominal wall, no corrosion allowance) schedule 140 holds about 4,073 psig at NPS 8 and about 3,659 psig at NPS 22. A schedule is therefore chosen size by size, from a calculation, and not once for a whole plant.

In this schedule the wall thickness coincides with XXS in NPS 10. Outside those sizes it does not, so never substitute one designation for the other without checking the number.

Guides and comparisons for this page

What a pipe schedule actually isWhy a schedule is a wall series and not a thickness.Pipe wall thickness calculationBarlow and ASME B31.3, corrosion allowance and mill tolerance.Pipe sizing by flow rate and velocityTurn a flow rate into a line size using velocity limits.

Common questions

What sizes is schedule 140 pipe made in?

ASME B36.10M publishes schedule 140 in 9 sizes, from NPS 8 through NPS 24. Wall thickness runs from 0.812 in (20.6 mm) at the small end to 2.062 in (52.4 mm) at the large end.

Does schedule 140 mean the same wall thickness in every size?

No. It is a series, not a thickness. The wall is 0.812 in (20.6 mm) at NPS 8 and 2.062 in (52.4 mm) at NPS 24, so the thickness always has to be read off the table for the size in hand.

How pipe schedules work →