I'm kind of surprised that GT 5U doesn't do this. I'm just getting into creating my first Multifarm, and the Assembler recipe for tubes requires Medium Voltage. Not directly, it's just that the recipe requires molten glass, which in turn requires MV, like almost all molten materials except rubber and tin. Just building a Themionic Fabricator instead was a lot easier, since I've yet to achieve MV tech. The fact I could bypass this felt like a bit of a cheat.
The less-expensive Forestry gear recipes are disabled. The Thermal Dynamics cheaper gears, which duplicate Forestry's recipes, are not, but I assume that's because GT 5U isn't really aware of Thermal Dynamics. I'm using Thermal Dynamics for fluid pipes that are better behaved than GT's.
The wiki doesn't really detail how Thermal Dynamics fluidpipes behave with each fluid. It says that the fluid transfer rate is inversely proportional to its viscosity, but how can we calculate it ? What is the rate for Steam for example ? Water and lava, hydrogen ? Does it know the viscosity of every GT Fluid ? I'm looking for a mod that has friendlier pipes than GT (sorry) but can still transfer the huge amounts of fluids required, but I can't find a suitable one.