DN 20 PN 16 flange: dimensions, bolt circle and drilling (EN 1092-1)
The DN 20 PN 16 flange to EN 1092-1 is 105 mm (4.13 in) across, with 4 holes of 14 mm (0.55 in) on a 75 mm (2.95 in) bolt circle, for M12 bolts; the pipe is 26.9 mm (1.06 in) outside. The holes straddle the centre lines, the first one 45° off, and the chord between neighbouring holes, which is the divider setting for stepping the drilling out, is 53 mm (2.09 in).
Dimensions
| Outside diameter | 105 mm (4.13 in) |
|---|---|
| Bolt circle (PCD) | 75 mm (2.95 in) |
| Number of holes | 4 |
| Hole diameter | 14 mm (0.55 in) |
| Bolts | M12 |
| Pipe outside diameter | 26.9 mm (1.06 in) |
| Angle between holes | 90° |
| First hole from the centre line | 45° |
| Chord between neighbouring holes | 53 mm (2.09 in) |
Draw this flange: 1:1 template and DXF
Hole coordinates
From the centre of the flange, in mm, with the first hole 45° off the horizontal axis and the others counter-clockwise, as the standards lay the drilling out.
| Hole | Angle | x (mm) | y (mm) |
|---|---|---|---|
| 1 | 45° | 26.2 | 26.2 |
| 2 | 135° | -26.2 | 26.2 |
| 3 | 225° | -26.2 | -26.2 |
| 4 | 315° | 26.2 | -26.2 |
Questions
- How many bolts does a %{size} %{class} flange have?
- %{holes}, of %{bolt}, through holes of %{hole} on a %{circle} bolt circle.
- What is the bolt circle of a %{size} %{class} flange?
- %{circle}. The holes are %{angle}° apart, and the first one sits %{half}° off the centre line, so that two flanges mate in any symmetric position. The chord between neighbouring holes is %{chord}.
- Can a %{size} %{class} flange be cut from plate?
- As a plate flange, for low pressure: ducts, tanks, water lines. The outline and the drilling above are what the flange calculator draws, with the 1:1 template and the DXF for plasma or laser. A pressure flange to %{standard} is forged, with a hub and a raised face, and its thickness and facing come from the standard.