Actually the pressure within your aircraft’s fuel manifold (which is the pressure of interest here) for a given flow rate will be specific to your aircraft more so than to the fuel truck. And that pressure to flow rate will depend on how you have your fuel system. Example, the plane I fly can have fuel flowing to up to 8 tanks at tha same time. The pressure/fuel flow relationsip will be different when only one fill valve to one tank is open than when all 8 valves are open. But we don’t have to worry about the pressure fuel flow limit as our refuelling panel has a pressure gauge which displays the fuel pressure at the hose fitting ( or very close to it anyway.) So as long as the gauge reads below the max pressure limitation you don’t need to worry about flow rates.