A 3-way fitting is a control fitting that divides the flow and return flow rates. This allows return temperatures to be raised or flow temperatures to be limited, for example. A distinction is made between a 3-way mixer and a 3-way valve.
Table 1. Differences between 3-way mixers and 3-way valves| 3-way mixer | 3-way valves |
|---|
| The media are mixed by a rotary movement | The media is mixed by a stroke movement |
| Smaller nominal pressure levels available | Larger nominal pressure levels also available |
| Larger leakage rate | Smaller leakage rates |
| Pump is installed downstream of the control valve | Pump is installed before the control valve |
| Less expensive | More cost-intensive |
