6. The Eaton orbital valve acts as a steering gearbox of sorts, in that it is what transmits your steering inputs as you turn the wheel. Atop the four-port orbital are lines controlling left and right inputs, a feed line from the pump and return to the fluid reservoir. This particular orbital is set up for a 4.2 lock-to-lock tuning ratio. Matching the correct orbital and pump gpm (gallons per minute) is often application specific and may take some fine-tuning to get right.