International Pipe Standards and Pipe-Size Tables
- 4-inch schedule 40 pipe has an OD of
4. 5 inches, 0.237-inch wall, for an ID of
4. 026 inches. - 4-inch schedule 80 pipe has an OD of
4. 5 inches, 0.337-inch wall, for an ID of
3. 826 inches.
Or
- 100 mm schedule 40 pipe has an OD of
114 .30 mm, 6.02 mm wall, for an ID of
102 .26 mm. - 100 mm schedule 80 pipe has an OD of
114 .30 mm, 8.56 mm wall, for an ID of
97 .18 mm.
Only schedules (wall thicknesses) 40 and
80 cover the full range of sizes from^1 / 8 - inch
(3 mm) up to 24-inch (600 mm) nominal sizes
and are the most commonly used and avail-
able pipe.
In most of the European Union, pipe is
manufactured to DIN standards, and DIN
2448 pipe is standard pipe. DIN pipe is speci-
fied in millimeters, as OD and wall thickness.
So a DIN 2448 pipe 25.4 mm OD and 2.6 mm
wall would be specified as “ 25. 4 2. 6 .”
In the United Kingdom, piping to EN
10255 (steel tubes appropriate for screwing
to BS 21 threads) is also used where the
pipe is screwed rather than flanged. These
are generally referred to as “Blue Band”
and “Red Band,” according to their banded
identification marks. The different colors
refer to the grade or weight of pipe: Red
Band, being heavy grade, is commonly used
for steam pipe applications. Blue Band,
being medium grade, is commonly used for
air-distribution systems and low-pressure,
low-temperature fluid applications. The
colored bands are 50 mm wide, and their
positions on the pipe give its length. Pipes
less than 4 meters in length only have a
colored band at one end, while pipes of 4 to
7 meters in length have a colored band at
either end.TABLE B-1. STANDARD METRIC—U.S. PIPE COMPARISON
Nominal Pipe^1 / 2 3 / 4 111 / 4 11 / 2 221 / 2 34 6
Size, in.
Nominal Pipe 15 20 25 32 40 50 65 80 100 150
Size, mm
Schedule 40, 0.622 0.824 1.049 1.380 1.610 2.067 2.469 3.068 4.026 6.065
ID in.
Schedule 40, 15.8 21 26.6 35.1 40.9 52.5 62.7 77.9 102.3 154.1
ID mm
Schedule 80, 0.546 0.742 0.957 1.278 1.500 1.939 2.323 2.900 3.826 5.761
ID in.
Schedule 80, 13.8 18.9 24.3 32.5 38.1 49.2 59 73.7 97.2 146.4
ID mm
Schedule 160, 0.466 0.614 0.815 1.160 1.338 1.689 2.125 2.626 3.438 5.189
ID in.
Schedule 160, 11.7 15.6 20.7 29.5 34 42.8 53.9 66.6 87.3 131.8
ID mm
DIN 2448, 17.3 22.3 28.5 37.2 43.1 60.3 70.3 82.5 107.1 159.3
ID mm
English-unit/inch sizes in bold