About Flow Rate Conversions 
    Design 
    calculations have been made using the following unit convention factors to 
    maintain design consistency 
  Normal flow, Normal 
    Cubic Meters per Hour, (Nm3/hr)  
    Normal Conditions are defined as: Tn = 20.0 ºC, (68 ºF) Pn = 1.01 bara, (14.72 
    psia)  
    Note: the definition of Normal conditions are consistent with the calibration 
    of the CME. 
  Standard 
    flow, Standard Cubic Feet per Minute, (SCFM)  
    Standard Conditions 
    for the calculation of SCFM are defined as: Ts= 15.6 ºC, (61 ºF) Ps= 1.01 
    bara, (14.72 psia) 
    Note: the definition of Standard conditions are consistent with the calibration 
    of the CME. 
  Standard 
    flow, Standard Liters per Minute, (SLPM)  
    Standard Conditions for the calculation of SLPM are defined as: Tn= 0 ºC, 
    (32 ºF) Pn= 1.01 bara, (14.72 psia) 
    Note: the definition of SLPM conditions are consistent with the calibration 
    of the CME. 
  Standard 
    flow, Standard Cubic Centimeters per Minute, (SCCM) 
    Standard Conditions for the calculation of SCCM are defined as: Tn= 0 ºC, 
    (32 ºF) Pn= 1.01 bara, (14.72 psia) 
    Note: the definition of SCCM conditions are consistent with the calibration 
    of the CME. 
  Conversion 
    basis and Flow Concerversion Table shows the calculation basis for the flow 
    rate conversions as used by  SAES Pure Gas.  
  Note: Ratios 
    toward the right side of the Figure are acutal conversion used in the Crane 
    Companion 
   
  
  Standard flow, SCFM 
     
    Ts = 61 deg F pV = mRT  
    Ps = 14.696 PSIA m = 0.07374 lbm per SCF  
    R = 55.12 (ft lbf)/(lbm deg R) 0.22603 SCFM per lbm  
    M = 28.0134 mol/mol 6.33176 SCFM per (lb mol)/hr  
    Gas = Nitrogen 
  Nm3/SCFM = 1.71928  
    SCFM/Nm3/hr = 0.58164 
  Normal 
    flow, Nm3/hr  
    Tn = 20 deg C  
    Pn = 14.72 PSIA pV = mRT  
    Pn = 101490.8 Pa m = 1.16726 lbm per Nm3  
    R = 296.6 J/(kg deg K) 0.3886 Nm3/hr per lbm  
    M = 28.0134 10.88605 Nm3 per (lb mol)/hr  
    Gas = Nitrogen 
  Nm3/SLPM 
    = 0.0644  
    SLPM/Nm3/hr = 15.5275 
  Standard 
    flow, SLPM  
    Ts = 32 deg F pV = mRT  
    Ps = 14.72 PSIA m = 0.00276 lbm per SL  
    R = 55.12 (ft lbf)/(lbm deg R) 6.03401 SLPM per lbm  
    M = 28.0134 mol/mol 169.0333 SLPM per (lb mol)/hr  
    Gas = Nitrogen 
 
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