Composer needs geometry to work. There is no possibility to create FREE material Animation. Pipes and tanks are geometry. So you are able to use textures within this geometric system.
Water, sand, fire, gas, ... needs something like a free form simulation/animation. If we need something like a free flow, we create the rest of the animation and afterwards we use a particular add-in for Adobe Aftereffects to add this to the avi.
Here you see screenshot with smoke, water, fire integrated at the end into the video.
Adobe After Effects turned out to be perfect for my purposes.