ASME B36.10M (welded and seamless wrought steel pipe) · DN 550

22 inch Schedule 120 pipe

Outside diameter 22.000" (558.80 mm), wall 1.625" (41.28 mm), inside diameter 18.750" (476.24 mm), 353.94 lb per foot.

Inside diameter
18.750"
476.24 mm · wall 1.625"

Dimensions

Published dimensions for 22 inch Schedule 120 pipe.
Trade sizeNPS 22 · DN 550
ScheduleSchedule 120
StandardASME B36.10M (welded and seamless wrought steel pipe)
Outside diameter22.000" · 558.80 mm · designated 559 mm in the metric column
Wall thickness1.625" · 41.28 mm
Inside diameter18.750" · 476.24 mm
Weight, plain end353.94 lb/ft · 527.05 kg/m

Cross-check: the standard plain-end weight formula W = 10.6802 x t x (OD - t) gives 353.61 lb/ft here, 0.1% from the published 353.94 lb/ft. The published figure is the one printed above.

Why 22 inch pipe is not 22 inches

Nominal Pipe Size is a label, not a measurement. NPS 22 pipe has an outside diameter of 22.000 inches, and it keeps that outside diameter in every schedule made. What the schedule number changes is the wall: at schedule 120 the wall is 1.625 inches, so the bore comes out at 18.750 inches.

That is the practical consequence. Fittings, flanges, supports and threading dies are sized to the outside diameter, so they fit any schedule of the same trade size. Flow, pressure drop and anything that has to pass through the pipe depend on the inside diameter, which changes with every schedule. Order by trade size and schedule; work your hydraulics from the bore.

Other schedules in NPS 22

Same outside diameter of 22.000 inches throughout - only the wall and the bore move.

Every other published schedule for NPS 22.
ScheduleWall (in)ID (in)Weight (lb/ft)
Schedule 50.18821.62443.84
Schedule 100.25021.50058.13
Schedule 200.37521.25086.69
Schedule 300.50021.000114.92
Schedule 600.87520.250197.6
Schedule 801.12519.750251.05
Schedule 1001.37519.250303.16
Schedule 1401.87518.250403.38
Schedule 1602.12517.750451.49
Standard wall (STD)0.37521.25086.69
Extra strong (XS)0.50021.000114.92
Schedule 5S0.18821.624not published
Schedule 10S0.21821.564not published

Frequently asked questions

What is the wall thickness of 22 inch schedule 120 pipe?

1.625 inches (41.28 mm). The outside diameter is 22.000 inches (558.80 mm) whatever the schedule, so this wall leaves an inside diameter of 18.750 inches.

What is the inside diameter of 22 inch schedule 120 pipe?

18.750 inches (476.24 mm). Inside diameter is outside diameter minus twice the wall: 22.000 - 2 x 1.625 = 18.750 inches.

Is 22 inch pipe actually 22 inches?

No. NPS 22 is a trade size, not a measurement. The pipe measures 22.000 inches across the outside and 18.750 inches across the bore in this schedule. Only the outside diameter is fixed across schedules.

How much does 22 inch schedule 120 pipe weigh?

353.94 pounds per foot plain end (527.05 kg per metre), for carbon steel. Stainless of the same dimensions runs a little lighter, and the figure excludes coatings, linings and fittings.

Not published here

2 schedules at NPS 22 appear in only one of the published tables cross-checked for this section, so they are named rather than printed: 40S, 80S. Everything shown above carries at least two independent sources.

Where this table stops

This table runs from NPS 1/8 to NPS 24 and stops there. ASME B36.10M itself continues to NPS 80; those larger sizes are not carried here, so a size above NPS 24 is missing rather than undefined.

Where these figures come from

Dimensions are as defined by ASME B36.10M (welded and seamless wrought steel pipe). This site is an independent reference and is not affiliated with, endorsed by or approved by any standards body.

Every value on this page was cross-checked against 4 independent published sources:

Nearby sizes

Schedule 120 in other trade sizes