subroutine Pump_OffMode_Solver(Pump_No)
    
    use Pumps_VARIABLES
    !use CPumpsVariables
    !use CDrillingConsoleVariables
    !use CDataDisplayConsoleVariables
    !use CSimulationVariables
    !use CDrillWatchVariables
    !use CSounds
    
    
    IMPLICIT NONE
    INTEGER :: Pump_No
    
    
        PUMP(1)%N_new = 0.e0
    
        !========================== Pump 1 Rate limit ==========================
        if (((PUMP(1)%N_new-PUMP(1)%N_old)/PUMP(1)%time_step)>PUMP(1)%RateChange) then
            PUMP(1)%Speed =(PUMP(1)%RateChange*PUMP(1)%time_step)+PUMP(1)%N_old
        else if (((PUMP(1)%N_old-PUMP(1)%N_new)/PUMP(1)%time_step)>PUMP(1)%RateChange) then
            PUMP(1)%Speed = (-PUMP(1)%RateChange*PUMP(1)%time_step)+PUMP(1)%N_old
        else
            PUMP(1)%Speed = PUMP(1)%N_new
        end if
        !=======================================================================
        
                
        
        PUMP(Pump_No)%Flow_Rate = PUMP(1)%FlowRatePerSTK*4118.e0*0.01e0*(PUMP(Pump_No)%Speed/PUMP(Pump_No)%Trans_Ratio)      ![gpm]
        PUMP(Pump_No)%Hydraulic_HorsePower = ( (PUMP(Pump_No)%Flow_Rate/0.01e0)*PUMP(Pump_No)%Max_Pressure)/(168067.e0*PUMP(Pump_No)%Mech_Efficiency)   ![HHP]
        if ( PUMP(Pump_No)%StandPipe_Pressure>=PUMP(Pump_No)%Max_Pressure ) then
            !print*, 'pumps critical'
            PUMP(Pump_No)%Flow_Rate = (1714.e0*PUMP(Pump_No)%Hydraulic_HorsePower)/PUMP(Pump_No)%Max_Pressure      ![gpm]
            PUMP(Pump_No)%Speed     = ( PUMP(Pump_No)%Flow_Rate/(PUMP(1)%FlowRatePerSTK*4118.e0*0.01e0) )*PUMP(Pump_No)%Trans_Ratio                ![rpm]
        end if
        
        total_pumps%Total_Pump_GPM = PUMP(1)%Flow_Rate+PUMP(2)%Flow_Rate+PUMP(3)%Flow_Rate
        total_pumps%Total_Pump_SPM = (PUMP(1)%Speed/PUMP(1)%Trans_Ratio)+(PUMP(2)%Speed/PUMP(2)%Trans_Ratio)+(PUMP(3)%Speed/PUMP(3)%Trans_Ratio)
        
        
        
        !Call Set_MP1SPMGauge( sngl(1-PUMP(1)%SPMGaugeMalf)*real((PUMP(1)%Speed/PUMP(1)%Trans_Ratio),8) )
        !SPM1 = MP1SPMGauge
        !PUMP(1)%SoundSPM = INT(PUMP(1)%Speed/PUMP(1)%Trans_Ratio)
        !Call SetSoundMP1( PUMP(1)%SoundSPM )
        
        
        
        
        
end subroutine Pump_OffMode_Solver