Here is an intersting project I am trying to work out , a Volvo excavator brand new is being set up to do concrete demo work , there are two attachment for it , one uses full system pressure and the other is senitive to pressure and flow must not exceed 2000psi @ 17 gpm , we are trying to come up with a way to easily make the switch from one attachment setting to the other , the dealer is kinda stumped and a local hydraulic shop is helping by trying to do it thru the computor as this machine does have a flow controll to the aux , where the operator and pick a flow off the screen such as 30gpm , 23 gpm, 15 gpm , and such ,but can't controll pressure ----- being that the pump is a pump on demand system , it's kinda tricky as to how and plumb it easiy , anyone dealt with these cards before