The most commonly used configurations are:
Three tanks "classical" with mix
Heated water in one tank, indirectly (using heat exchanger) heating Type-I fluid in separate tank. Pure, unheated Type-II/-IV fluid in the third tank. Sprays required water/Type-I mix or pure Type-II/-IV fluid.
Three tanks, with "double mix"
Heated water in one tank, indirectly (using heat exchanger) heating Type-I fluid in separate tank. Pure and heated (also indirectly) Type-II/-IV in the third tank. Sprays selected water/Type-I mix or selected water and Type-II/-IV or pure Type-II/-IV fluid.
Two tanks, with mix of water and Type-II/-IV
Heated water in one tank, indirectly heating (by heat exchanger) Type-II/-IV fluid in the second tank. Sprays either the required water/Type-II/-IV mix, or pure Type-II/IV fluid.
Two tanks, premix-I
Premix of heated water and Type-I fluid in one tank, and separate Type-II/-IV tank. Sprays the premix ADF or pure Type-II/-IV fluid.
Two tanks, premix-II/-IV
Heated water and Type-II/-IV premix, with this premix heated indirectly (using heat exchanger) in one tank, and separate Type-II/-IV tank. Sprays the premix ADF or pure Type-II/-IV fluid.

