The INFICON ISO-K welding flange (steel A570) forms the large-diameter ISO-K connection on vacuum and high-vacuum lines. It comes in DN 160 and DN 250 and is designed and tested for a leak rate below 1×10⁻⁹ mbar·l/s.
| Connection | ISO-K (DN 160 / 250) |
| Manufacturing Standards | ISO 1609, DIN 28404, Pneurop 6606 |
| Material | Steel A570 |
| Leak Rate | Designed and tested for below 1×10⁻⁹ mbar·l/s |
| Flange Outer Diameter (mm) | DN 160: 180 / DN 250: 290 |
| Weld Pipe Outer Diameter (mm) | DN 160: 159 / DN 250: 267 |
| Weld Pipe Inner Diameter (mm) | DN 160: 153.2 / DN 250: 261 |
| Flange Thickness (mm) | DN 160 and 250: 12 |
| Part Numbers | DN 160: 212-023 / DN 250: 212-025 |
| Environmental Compliance | Compliant with RoHS Directive 2011/65/EU |