Standard sizes of press copper couplings (straight)
- Standard EN 1254-1 — press fittings, EN 1057 — copper tubes
Seal: EPDM (water), HNBR (gas)
Temperature: up to +110 °C
Pressure: up to 16 bar
| Pipe outer diameter (mm) | Coupling designation | Application |
| 15 × 15 | Straight coupling 15 | Plumbing, radiators |
| 18 × 18 | Straight coupling 18 | European standard |
| 22 × 22 | Straight coupling 22 | Water supply, heating |
| 28 × 28 | Straight coupling 28 | Private houses, boiler rooms |
| 35 × 35 | Straight coupling 35 | Apartment buildings |
| 42 × 42 | Straight coupling 42 | Commercial facilities |