Volvo Penta D7A T Operator's Manual page 56

Maintenance: Cooling system general
Cooling system D7A TA KC (2-circuit)
The engine cooling water is cooled by, e.g, a box cooler, a grid cooler, or any other external heat exchanger.
The HT-circuit is cooling the cylinder liners, the cylinder heads, and the lubrication oil.. An engine driven HT-pump
circulates the coolant through the engine.
The LT-circuit is cooling the charge air. An engine driven LT-pump circulates the coolant through the CAC.
Drain points HT-circuit
Drain points LT-circuit
56
1. Engine
2. HT-pump
3. Thermostat valve
4. Expansion tank
5. LT-pump
6. Charge air cooler
7. HT-circuit
8. LT-circuit