[BDCS]

errr yes  The pump flow is set in stone for the revs, the nozzle dictates the pressure at those revs, the unloader limits the maximum pressure within the hose. SO thats why the unloader is set just higher than the pressure developed by the nozzle. The pressure behind the nozzle is zero unless the trigger is open. The unloader is a trapped pressure unloader - it unloads untill there is a decay in that trapped pressure when it will load up again, the trapped pressure is in the hose.