Oil is heated via a copper pipe heat exchanger in the aux. fuel tank tied into the cooling system. It leaves there hot and goes through a WEBB fuel heater/filter water seperator that has a 30 micron screen. It leaves there hotter and goes through a stock inline plastic clear MB filter.
It then goes through another stock MB spin on filter I salvaged from a wrecked MB.
The fuel then goes to a electric solenoid where either the veg or diesel is sent to the lift pump and then the injection pump. The diesel filtering system is totally seperate from the veg. The return line is also controlled by a solenoid. When on diesel, fuel is returned to tank. When on veg, its looped back to pump. If I delay switching the return solenoid after switching back to diesel, the veg filter gets back flushed with diesel making switch over to veg sooner next time.(return fuel has no where to go but back up the veg line)