Injection circuit

The injection circuit is characterised by an injection line between the pump and upstream of the control valve. The pump and control valves can be installed in the flow or return. The injection line ensures a fixed admixture of part of the mass flow. The circuit type can be regarded as an extended diverter circuit.

Figure 1. Injection circuit with a 3-way valve in the flow line


Characteristics of the injection circuit:
  • There is one pump in the consumer circuit and one in the generator circuit
  • There is no variable-volume circuit in the circuit.
  • There are different temperatures in the producer and generator circuits
  • The mixer is relieved and can be better regulated.
Typical applications of the injection circuit are
  • Radiator system
  • Air heater
  • Boiler charging
  • Low temperature heating