Cv Calculator for Liquids      
  The coefficient of flow (Cv) is a formula which is used to determine a valve's flow under various conditions and to select the correct valve for a flow application. Cv expresses the flow in gallons per minute of 60°F water with a pressure drop across the valve of 1 psi. The formula becomes more intricate for gases, as gases are compressible fluids and are thus affected by temperature. Furthermore, two formulas are required to accurately estimate flow. When the upstream pressure equals or exceeds two times the downstream pressure, it is known as "choked flow" and requires the Critical Flow formula. If the upstream pressure is less than two times the downstream pressure, the Sub-Critical flow formula is utilized. Don't worry, we have simplified the process and built the two formulas into our calculator. Just input the application parameters and we will do the rest!

This Cv and Flow calculator can help you select the right valve for a given application providing you with either the Cv or the Flow Rate. Enter the application parameters below:
 
  Calculate Cv for Liquids   Calculate Cv for Gases  
Cv = Q * (G/(P1-P2)
Critical Flow
Cv = Q * √(G * T) / (816* P1)
Sub-Critical Flow
        Cv = (Q/962) * √((G * T) / (P12* P22))  
  Q (GPM)=   Q (SCFH) =  
  P1=   P1=  
  P2=   P2=  
  G=   T=  
        G=  
             
  Cv=   Cv=  
             
  Calculate Flow Rate for Liquids (GPM)   Calculate Flow Rate for Gases (SCFH)  
  Q = Cv * √(dP/G)   Critical Flow  
      Q = Cv * (816 * P1)/ √(G * T)  
        Sub-Critical Flow  
        Q = 962 * Cv  * √((P12* P22) / (G * T))  
  Cv=   Cv=  
  P1=   P1=  
  P2=   P2=  
  G=   T=  
        G=  
             
  Q (GPM)=   Q (SCFH) =  
             
             
             
        Cv = Valve flow coefficient    
  Cv = Valve flow coefficient     Q  = Volumetric flow rate (SCFH - Standard Cubic Feet / Hour)  
  Q  = Flow rate (GPM - Gallons per Minute)   P1 = Inlet Pressure (psia)    
  P1 = Inlet Pressure (psia)     P2 = Outlet Pressure (psia)    
  P2 = Outlet Pressure (psia)     T = Temperature (F)    
  G = Specific Gravity of the liquid   G = Specific Gravity of the gas    
             
             
             
  SVF V8 Series Three Piece Ball Valve   SVF VB41 Series Flanged Ball Valve  
         
           
           
  Liquid Specific Gravity   Gas Specific Gravity
  Acetaldehyde CH3CHO 0.79   Acetylene (ethyne) - C2H2 0.899
  Acetic acid 5% - vinegar 1.006   Air 1
  Acetic acid - 10% 1.014   Alcohol vapor 1.601
  Acetic acid - 50% 1.061   Ammonia - NH3 0.59
  Acetic acid - 80% 1.075   Argon - Ar 1.38
  Acetic acid - concentrated 1.055   Arsine 2.69
  Acetic acid anhydride (CH3COO)2O 1.087   Benzene - C6H6 2.6969
  Acetone CH3COCH3 0.792   Blast Furnace gas 1.02
  Alcohol - allyl 0.855   1,2 - Butadiene - C4H6 1.8676
  Alcohol - butyl-n 0.81   Butane - C4H10 2.0061
  Alcohol - ethyl (grain) C2H5OH 0.789   1-Butene (Butylene)- C4H8 1.9372
  Alcohol - methyl (wood) CH3OH 0.79   Isobutene - C4H8 1.94
  Alcohol - propyl 0.804   Carbon dioxide - CO2 1.5189
  Aluminum sulfate 36% solution 1.055   Carbon monoxide - CO 0.9667
  Ammonia 0.662   Carbureted Water Gas 0.63
  Aniline 1.022   Chlorine - Cl2 2.486
  Automotive crankcase oils 0.88-0.94   Coke Oven Gas 0.44
  Automotive gear oils 0.88-0.94   Cyclobutane 1.938
  Beer 1.01   Cyclohexane 2.9057
  Benzene (benzol) C6H6 0.899   Cyclopentane 2.4215
  Benzine 0.69   Cyclopropane 1.451
  Bone oil 0.918   n - Decane 4.9125
  Boric acid H3BO3 1.014   Deutrium - D2 0.07
  Bromine 2.9   Digestive Gas (Sewage or Biogas) 0.8
  Butane-n 0.584   2,3 - Dimethylbutane 2.9753
  Butyric acid 0.959   2,2 - Dimetylpentane 3.4596
  Calcium chloride 5% 1.04   Diisobutyl 3.9439
  Calcium chloride 25% 1.23   Ethane - C2H6 1.0378
  Carbolic acid (phenol) 1.08   Ether vapor 2.586
  Carbon tetrachloride CCl4 1.594   Ethylbenzene 3.6655
  Carbon disulfide CS2 1.293   Ethyl Chloride - C2H5Cl 2.23
  Castor Oil 0.96   Ethylene (Ethene) - C2H4 0.9686
  China wood oil 0.943   3 - Ethylpentane 3.4596
  Chloroform 1.489   Fluorine 1.31
  Coconut oil 0.925   Helium - He 0.138
  Cod liver oil 0.920-0.925   n - Heptane 3.4596
  Corn oil 0.924   n - Hexane 2.9753
  Cotton seed oil 0.88-0.93   Hydrogen 0.0696
  Creosote 1.04-1.10   Hydrogen chloride - HCl 1.268
  Crude oil 48o API 0.79   Hydrogen sulfide - H2S 1.1763
  Crude oil 40o API 0.825   Hydrofluoric acid 2.37
  Crude oil 35.6o API 0.847   Hydrochloric acid 1.261
  Crude oil 32.6o API 0.862   Illuminating gas 0.4
  Crude oil Salt creek 0.843   Isobutane 2.0068
  Decane-n 0.73   Isobutene 1.9372
  Diethylene glycol 1.12   Isooctane 3.9439
  Diethyl ether 0.714   Isopentane 2.4911
  Diphenylamine 1.16   Isoprene 2.3519
  Diesel Fuel Oil 2D/3D/4D/5D 0.81 - 0.96   Isopropylbenzene 4.1498
  Dowtherm 1.056   Krypton 2.89
  Ether, sulfuric 0.72   Marsh gas 0.555
  Ethyl acetate CH3COOC2H3 0.907   Mercury vapor 6.94
  Ethyl bromide C2H3Br 1.45   Methane - CH4 0.5537
  Ethylene bromide 2.18   Methylcyclopentane 2.9057
  Ethylene chloride 1.246   Methylcyclohexane 3.39
  Ethylene glycol 1.125   Methyl Chloride 1.74
  Fluoric acid 1.5   2 - Methylhexane 3.4596
  Formic acid - 10% 1.025   2 - Methylpentane 2.9753
  Formic acid - 50% 1.121   Natural Gas (typical) 0.60 - 0.70
  Formic acid - 80% 1.186   Neohexane 2.9753
  Formic acid - concentrated 1.221   Neopentane 2.4911
  Trichlorofluoromethane - 11 1.49   Neon 0.697
  Dichlorodifluoromethane - 12 1.33   Nitric oxide - NO 1.037
  Dichlorofluoromethane - 21 1.37   Nitrogen - N(pure) 0.9669
  Furfurol 1.159   Nitrogen - N(atmospheric) 0.9723
  Fuel oils 1/2/3/5A/5B/6 0.82-0.95   Nitrous oxide - N2O 1.53
  Gas oils 0.89   n - Nonane 4.4282
  Gasoline a 0.74   n - Octane 3.9439
  Gasoline b 0.72   Oxygen - O2 1.1044
  Gasoline c 0.68   Ozone 1.66
  Glycerine 100% 1.26   n - Pentane 2.4911
  Glycerine 50% water 1.13   Phosgene 1.39
  Glucose 1.35-1.44   Propane - C3H8 1.5219
  Heptane-n 0.688   Propene (Propylene) - C3H6 1.4529
  Hexane-n 0.664   Sasol 0.42
  Ink printers 1.0-1.4   Silane 1.11
  Kerosene 0.78-0.82   Styrene 3.5959
  Jet fuel 0.82   Sulfur Dioxide - SO2 2.264
  Lard 0.96   Toluene - Methylbenzene 3.1082
  Lard oil 0.91-0.93   Triptane 3.4596
  Linseed oil 0.92-0.94   Water gas (bituminous) 0.71
  Mercury 13.6   Water vapor 0.6218
  Methyl acetate 0.93   Xenon 4.53
  Methyl iodide 2.28   o - Xylene 3.6655
  Mineral oil 0.92      
  Milk 1.02-1.05      
  Molasses A first 1.40-1.46      
  Molasses B second 1.43-1.48      
  Molasses C blackstrap 1.46-1.49      
  Muriatic acid 1.2      
  Naphtha 0.76      
  Naphthalene 1.145      
  Neatsfoot oil 0.917      
  Nitric acid 1.5      
  Nitrobentzene 1.203      
  Nonane-n 0.722      
  Octane-n 0.707      
  Olive oil 0.91 - 0.92      
  Palm oil 0.924      
  Peanut oil 0.92      
  Pentane-n 0.65      
  Petroleum oil 0.82      
  Phosphoric acid 1.78      
  Potassium hydrate 1.24      
  Rape oil 0.92      
  Sodium chloride 1.19      
  Sodium hydrate 1.27      
  Sulphuric acid 1.84      
  Tar 1      
  Tuluol 0.87      
  Turpentine oil 0.87      
  Vinegar 1.08      
  Water. fresh 1      
  Water. sea 36 oF 1.02      
  Whale oil 0.92      
  Xylene 0.87