Reducers be applied, to change from pipe diameter in one direction. Standard there are 2 possibilities, the concentric reducer, is usually used in vertical pipe lines, and the eccentric 1/2 reducer that is used in horizontal pipe lines.
| NPS | D(Large End) | D1(Small End) | Length-H |
| 16×14 | 16 | 14 | 14 |
| 16×12 | 16 | 12.75 | 14 |
| 16×10 | 16 | 10.75 | 14 |
| 16×8 | 16 | 8.62 | 14 |
| 18×16 | 18 | 16 | 15 |
| 18×14 | 18 | 14 | 15 |
| 18×12 | 18 | 12.75 | 15 |
| 18×10 | 18 | 10.75 | 15 |
| 20×18 | 20 | 18 | 20 |
| 20×16 | 20 | 16 | 20 |
| 20×14 | 20 | 14 | 20 |
| 20×12 | 20 | 12.75 | 20 |
| 22×20 | 22 | 20 | 20 |
| 22×18 | 22 | 18 | 20 |
| 22×16 | 22 | 16 | 20 |
| 22×14 | 22 | 14 | 20 |
| 24×22 | 24 | 22 | 20 |
| 24×20 | 24 | 20 | 20 |
| 24×18 | 24 | 18 | 20 |
| 24×16 | 24 | 16 | 20 |
| 26×24 | 26 | 24 | 24 |
| 26×22 | 26 | 22 | 24 |
| 26×20 | 26 | 20 | 24 |
| 26×18 | 26 | 18 | 24 |
| 28×26 | 28 | 26 | 24 |
| 28×24 | 28 | 24 | 24 |
| 28×22 | 28 | 22 | 24 |
| 28×20 | 28 | 20 | 24 |
| 28×18 | 28 | 18 | 24 |
| 30×28 | 30 | 28 | 24 |
| 30×26 | 30 | 26 | 24 |
| 30×24 | 30 | 24 | 24 |
| 30×22 | 30 | 22 | 24 |
| 30×20 | 30 | 20 | 24 |
| 32×30 | 32 | 30 | 24 |
| 32×28 | 32 | 28 | 24 |
| 32×26 | 32 | 26 | 24 |
| 32×24 | 32 | 24 | 24 |
| 34×32 | 34 | 32 | 24 |
| 34×30 | 34 | 30 | 24 |
| 34×28 | 34 | 28 | 24 |
| 34×26 | 34 | 26 | 24 |
| 34×24 | 34 | 24 | 24 |
| 36×34 | 36 | 34 | 24 |
| 36×32 | 36 | 32 | 24 |
| 36×30 | 36 | 30 | 24 |
| 36×28 | 36 | 28 | 24 |
| 36×26 | 36 | 26 | 24 |
| 36×24 | 36 | 24 | 24 |
| 38×36 | 38 | 36 | 24 |
| 38×34 | 38 | 34 | 24 |
| 38×32 | 38 | 32 | 24 |
| 38×30 | 38 | 30 | 24 |
| 38×28 | 38 | 28 | 24 |
| 38×26 | 38 | 26 | 24 |
| 38×24 | 38 | 24 | 24 |
| 38×22 | 38 | 22 | 24 |
| 38×20 | 38 | 20 | 24 |
| 40×38 | 40 | 38 | 24 |
| 40×36 | 40 | 36 | 24 |
| 40×34 | 40 | 34 | 24 |
| 40×32 | 40 | 32 | 24 |
| 40×30 | 40 | 30 | 24 |
| 40×28 | 40 | 28 | 24 |
| 40×26 | 40 | 26 | 24 |
| 40×24 | 40 | 24 | 24 |
| 40×22 | 40 | 22 | 24 |
| 40×20 | 40 | 20 | 24 |
| 42×40 | 42 | 40 | 24 |
| 42×38 | 42 | 38 | 24 |
| 42×36 | 42 | 36 | 24 |
| 42×34 | 42 | 34 | 24 |
| 42×32 | 42 | 32 | 24 |
| 42×30 | 42 | 30 | 24 |
| 42×28 | 42 | 28 | 24 |
| 42×26 | 42 | 26 | 24 |
| 42×24 | 42 | 24 | 24 |
| 42×22 | 42 | 22 | 24 |
| 44×42 | 44 | 42 | 24 |
| 44×40 | 44 | 40 | 24 |
| 44×38 | 44 | 38 | 24 |
| 44×36 | 44 | 36 | 24 |
| 44×34 | 44 | 34 | 24 |
| 44×32 | 44 | 32 | 24 |
| 44×30 | 44 | 30 | 24 |
| 44×28 | 44 | 28 | 24 |
| 44×26 | 44 | 26 | 24 |
| 44×24 | 44 | 24 | 24 |
| 44×22 | 44 | 22 | 24 |
| 46×44 | 46 | 44 | 28 |
| 46×42 | 46 | 42 | 28 |
| 46×40 | 46 | 40 | 28 |
| 46×38 | 46 | 38 | 28 |
| 46×36 | 46 | 36 | 28 |
| 46×34 | 46 | 34 | 28 |
| 46×32 | 46 | 32 | 28 |
| 46×30 | 46 | 30 | 28 |
| 46×28 | 46 | 28 | 28 |
| 46×26 | 46 | 26 | 28 |
| 46×24 | 46 | 24 | 28 |
| 48×46 | 48 | 46 | 28 |
| 48×44 | 48 | 44 | 28 |
| 48×42 | 48 | 42 | 28 |
| 48×40 | 48 | 40 | 28 |
| 48×38 | 48 | 38 | 28 |
| 48×36 | 48 | 36 | 28 |
| 48×34 | 48 | 34 | 28 |
| 48×32 | 48 | 32 | 28 |
| 48×30 | 48 | 30 | 28 |
| 48×28 | 48 | 28 | 28 |
| 48×26 | 48 | 26 | 28 |
| 48×24 | 48 | 24 | 28 |
| 50×48 | 50 | 48 | 28 |
| 50×42 | 50 | 42 | 28 |
| 50×36 | 50 | 36 | 28 |
| 50×30 | 50 | 30 | 28 |
| 50×24 | 50 | 24 | 28 |
| 50×20 | 50 | 20 | 28 |
| 52×50 | 52 | 50 | 28 |
| 52×48 | 52 | 48 | 28 |
| 52×42 | 52 | 42 | 28 |
| 52×36 | 52 | 36 | 28 |
| 52×30 | 52 | 30 | 28 |
| 52×24 | 52 | 24 | 28 |
| 54×52 | 54 | 52 | 28 |
| 54×48 | 54 | 48 | 28 |
| 54×42 | 54 | 42 | 28 |
| 54×36 | 54 | 36 | 28 |
| 54×30 | 54 | 30 | 28 |
| 54×24 | 54 | 24 | 28 |
| 56×54 | 56 | 54 | 28 |
| 56×48 | 56 | 48 | 28 |
| 56×42 | 56 | 42 | 28 |
| 56×36 | 56 | 36 | 28 |
| 56×30 | 56 | 30 | 28 |
| 56×24 | 56 | 24 | 28 |
| 58×56 | 58 | 56 | 28 |
| 58×54 | 58 | 54 | 28 |
| 58×48 | 58 | 48 | 28 |
| 58×42 | 58 | 42 | 28 |
| 58×36 | 58 | 36 | 28 |
| 58×30 | 58 | 30 | 28 |
| 60×58 | 60 | 58 | 28 |
| 60×54 | 60 | 54 | 28 |
| 60×48 | 60 | 48 | 28 |
| 60×42 | 60 | 42 | 28 |
| 60×36 | 60 | 36 | 28 |
| 60×30 | 60 | 30 | 28 |
