PipeData

Schedule 100 Pipe Dimensions

Wall thickness, bore and plain-end weight for all 9 sizes ASME B36.10M publishes in schedule 100, NPS 8 through NPS 24.

Schedule
Schedule 100
Sizes published
9 (NPS 8 to NPS 24)
Thinnest wall
0.594 in (15.1 mm) at NPS 8
Thickest wall
1.531 in (38.9 mm) at NPS 24
Standard
ASME B36.10M

Where schedule 100 is used

Schedule 100 is an intermediate heavy wall published only in the larger sizes. It is mostly found in high-pressure steam and feed water piping and is normally made to order.

Pipe wall thickness to scale, Schedule 100Pipe cross-sections drawn to scale at the same outside diameter so the wall thicknesses can be compared. NPS 8: 0.594 in wall on 8.625 in OD; NPS 16: 1.031 in wall on 16.000 in OD; NPS 24: 1.531 in wall on 24.000 in ODNPS 80.594 in wall on 8.625 in ODNPS 161.031 in wall on 16.000 in ODNPS 241.531 in wall on 24.000 in OD
Schedule 100 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 100 in every size

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

ASME B36.10M schedule 100 dimensions.
SizeDNOutside diameterWall thicknessInside diameterWeight, emptyWater (US gal/ft)This size
NPS 8DN 2008.625219.07 mm0.59415.09 mm7.437188.90 mm51.0075.89 kg/m2.257all schedules →
NPS 10DN 25010.750273.05 mm0.71918.26 mm9.312236.52 mm77.10114.74 kg/m3.538all schedules →
NPS 12DN 30012.750323.85 mm0.84421.44 mm11.062280.97 mm107.42159.86 kg/m4.993all schedules →
NPS 14DN 35014.000355.60 mm0.93823.83 mm12.124307.95 mm130.98194.91 kg/m5.997all schedules →
NPS 16DN 40016.000406.40 mm1.03126.19 mm13.938354.03 mm164.98245.52 kg/m7.926all schedules →
NPS 18DN 45018.000457.20 mm1.15629.36 mm15.688398.48 mm208.15309.76 kg/m10.041all schedules →
NPS 20DN 50020.000508.00 mm1.28132.54 mm17.438442.93 mm256.34381.47 kg/m12.407all schedules →
NPS 22DN 55022.000558.80 mm1.37534.92 mm19.250488.95 mm303.16451.15 kg/m15.119all schedules →
NPS 24DN 60024.000609.60 mm1.53138.89 mm20.938531.83 mm367.74547.25 kg/m17.887all 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 100 is 0.594 in (15.1 mm) at NPS 8 and 1.531 in (38.9 mm) at NPS 24. Measured against the pipe it belongs to, that is 6.9% of the outside diameter at the small end and 6.4% 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 100 holds about 2,915 psig at NPS 8 and about 2,632 psig at NPS 22. A schedule is therefore chosen size by size, from a calculation, and not once for a whole plant.

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 100 pipe made in?

ASME B36.10M publishes schedule 100 in 9 sizes, from NPS 8 through NPS 24. Wall thickness runs from 0.594 in (15.1 mm) at the small end to 1.531 in (38.9 mm) at the large end.

Does schedule 100 mean the same wall thickness in every size?

No. It is a series, not a thickness. The wall is 0.594 in (15.1 mm) at NPS 8 and 1.531 in (38.9 mm) at NPS 24, so the thickness always has to be read off the table for the size in hand.

How pipe schedules work →