Standard dimensions for piping reducers and expanders are recommended by ASME/ANSI standards.
Piping reducer
Piping reducers and expanders are tapered pipe joints used to join two pipes of different sizes together.
When the upstream pipe is larger in size, the joint is called a pipe reducer. As the flow goes from a large pipe to a 'reduced' pipe size.
Similarly, when the upstream pipe is smaller, flow goes from a small pipe to an 'expanded' pipe size. Hence in this case the tapered joint is called an 'expander' in this case.
Standard dimension calculator
You can use these calculators to quickly get standard dimensions for different sizes of piping reducers/expanders.
- Standard dimensions calculator for piping reducer / expander
- Standard pipe dimensions calculator as per ANSI standards
Standard reducer dimensions
| Nominal Pipe Size
(inches) |
Outside Diameter
(mm) |
Length
(mm) |
|
|---|---|---|---|
| Inch | D | P | H |
| 3/4 x 1/2 | 26.7 | 21.3 | 38 |
| 3/4 x 3/8 | 26.7 | 17.1 | 38 |
| 1 x 3/4 | 33.4 | 26.7 | 51 |
| 1 x 1/2 | 33.4 | 21.3 | 51 |
| 1 1/4 x 1 | 42.2 | 33.4 | 51 |
| 1 1/4 x 3/4 | 42.2 | 26.7 | 51 |
| 1 1/4 x 1/2 | 42.2 | 21.3 | 51 |
| 1 1/2 x 1 1/2 | 48.3 | 42.2 | 64 |
| 1 1/2 x 1 | 48.3 | 33.4 | 64 |
| 1 1/2 x 3/4 | 48.3 | 26.7 | 64 |
| 1 1/2 x 1/2 | 48.3 | 21.3 | 64 |
| 2 x 1 1/2 | 60.3 | 48.2 | 76 |
| 2 x 1 1/4 | 60.3 | 42.2 | 76 |
| 2 x 1 | 60.3 | 33.4 | 76 |
| 2 x 3/4 | 60.3 | 26.7 | 76 |
| 2 1/2 x 2 | 73 | 60.3 | 89 |
| 2 1/2 x 1 1/2 | 73 | 48.3 | 89 |
| 2 1/2 x 1 1/4 | 73 | 42.2 | 89 |
| 2 1/2 x 1 | 73 | 33.4 | 89 |
| 3 x 2 1/2 | 88.9 | 73 | 89 |
| 3 x 2 | 88.9 | 60.3 | 89 |
| 3 x 1 1/2 | 88.9 | 48.3 | 89 |
| 3 x 1 1/4 | 88.9 | 42.2 | 89 |
| 3 1/2 x 3 | 101.6 | 88.9 | 102 |
| 3 1/2 x 21/2 | 101.6 | 73 | 102 |
| 3 1/2 x 2 | 101.6 | 60.3 | 102 |
| 3 1/2 x 1 1/2 | 101.6 | 48.3 | 102 |
| 3 1/2 x 1 1/4 | 101.6 | 42.2 | 102 |
| 4 x 3 1/2 | 114.3 | 101.6 | 102 |
| 4 x 3 | 114.3 | 88.9 | 102 |
| 4 x 2 1/2 | 114.3 | 73 | 102 |
| 4 x 2 | 114.3 | 60.3 | 102 |
| 4 x 1 1/2 | 114.3 | 48.3 | 102 |
| 5 x 4 | 141.3 | 114.3 | 127 |
| 5 x 3 1/2 | 141.3 | 101.6 | 127 |
| 5 x 3 | 141.3 | 88.9 | 127 |
| 5 x 2 1/2 | 141.3 | 73 | 127 |
| 5 x 2 | 141.3 | 60.3 | 127 |
| 6 x 5 | 168.3 | 141.3 | 140 |
| 6 x 4 | 168.3 | 114.3 | 140 |
| 6 x 3 1/2 | 168.3 | 101.6 | 140 |
| 6 x 3 | 168.3 | 88.9 | 140 |
| 6 x 2 1/2 | 168.3 | 73 | 140 |
| 8 x 6 | 219.1 | 168.3 | 152 |
| 8 x 5 | 219.1 | 141.3 | 152 |
| 8 x 4 | 219.1 | 114.3 | 152 |
| 8 x 3 1/2 | 219.1 | 101.6 | 152 |
| 10 x 8 | 273.1 | 219.1 | 178 |
| 10 x 6 | 273.1 | 168.1 | 178 |
| 10 x 5 | 273.1 | 141.3 | 178 |
| 10 x 4 | 273.1 | 114.3 | 178 |
| 12 x 10 | 323.9 | 273.1 | 203 |
| 12 x 8 | 323.9 | 219.1 | 203 |
| 12 x 6 | 323.9 | 168.3 | 203 |
| 12 x 5 | 323.9 | 141.3 | 203 |
| 14 x 12 | 355.6 | 323.9 | 330 |
| 14 x 10 | 355.6 | 273.1 | 330 |
| 14 x 8 | 355.6 | 219.1 | 330 |
| 14 x 6 | 355.6 | 168.3 | 330 |
| 16 x 14 | 406.4 | 355.6 | 356 |
| 16 x 12 | 406.4 | 323.9 | 356 |
| 16 x 10 | 406.4 | 273.1 | 356 |
| 16 x 8 | 406.4 | 219.1 | 356 |
| 16 x 6 | 406.4 | 168.3 | 356 |
| 18 x 16 | 457 | 406.4 | 381 |
| 18 x 14 | 457 | 355.6 | 381 |
| 18 x 12 | 457 | 323.9 | 381 |
| 18 x 10 | 457 | 273.1 | 381 |
| 18 x 8 | 457 | 219.1 | 381 |
| 20 x 18 | 508 | 457 | 508 |
| 20 x 16 | 508 | 406.4 | 508 |
| 20 x 14 | 508 | 355.6 | 508 |
| 20 x 12 | 508 | 323.9 | 508 |
| 20 x 10 | 508 | 273.1 | 508 |
| 20 x 8 | 508 | 219.1 | 508 |
| 22 x 20 | 559 | 508 | 508 |
| 22 x 18 | 559 | 457 | 508 |
| 22 x 16 | 559 | 406.4 | 508 |
| 22 x 14 | 559 | 355.6 | 508 |
| 22 x 12 | 559 | 323.9 | 508 |
| 24 x 10 | 559 | 273.1 | 508 |
| 24 x 22 | 610 | 559 | 508 |
| 24 x 20 | 610 | 508 | 508 |
| 24 x 18 | 610 | 457 | 508 |
| 24 x 16 | 610 | 406.4 | 508 |
| 24 x 14 | 610 | 355.6 | 508 |
| 24 x 12 | 610 | 323.9 | 508 |
| 24 x 10 | 610 | 273.1 | 508 |
Standards for piping reducers
B16.1 (2005) - Gray Iron Pipe Flanges and Flanged Fittings: Classes 25, 125, and 250
This Standard covers Classes 25, 125, and 250 Gray Iron Pipe Flanges and Flanged Fittings. It includes: (a) pressure-temperature ratings; (b) sizes and method of designating openings of reducing fittings; (c) markings; (d) materials; (e) dimensions and tolerances; (f) bolting and gaskets; (g) pressure testing.
B16.5 (2009) – Pipe flanges and flanged fittings (2009)
This standard covers pressure-temperature ratings, materials, dimensions, tolerances, marking, testing and methods of designating for pipe flanges and flanged fittings
Here are more ASME/ANSI piping standards for reference.
