# Flow Calculator

## While this flow calculator will size your flowmeter for most liquids and gases in the more common flow unit dimensions, it is designed

for flow estimation and comparison purposes only. King Instrument Company does not guarantee the accuracy of this calculator without

the verification of Customer Service or Sales and is not responsible for any errors, omissions, or misrepresentations.

# Manual Calculations

**Gas Flowmeter Sizing**

*Click Here To Download A Printable Version*

Variable area flowmeters suitable for liquid service have a capacity rating based on water at 70° Fahrenheit. Flowmeters suitable

for gas service have a capacity rating based on air at STP (70°F, 14.7 PSIA) conditions. The correction factors listed below are

used to calculate the flow capacity when using a liquid other than water or a gas other than air at STP conditions.

##### GAS CORRECTION FORMULA

*Air Equivalent Flow Rate = **Customer Gas Flow Rate X Gas Correction Factor*

Step 1: Convert *Customer Gas Flow Rate* unit of measure to a standard unit of measure for air flow (SCFM or SCCM).

Step 2: Calculate *Gas Correction Factor* from given values.

Step 3: Calculate the product of the *Air Equivalent Flow Rate* from the *Customer Gas Flow Rate* and the *Gas Correction Factor.
*Step 4: Calculate the maximum or minimum flow rate for the customer’s conditions.

**Step 1: Convert**

*Customer Gas Flow Rate*unit of measure to a standardunit of measure for air flowCustomer Gas Flow Rate ________________

Converted Gas Flow Rate ________________ SCFM / SCCM

Gas Flow Rate Conversions | ||||

From | To SCFM | From | To SCCM | |

SCFH | Divide by 60 | SCFM | Multiply by 28,317 | |

SCIM | Divide by 1,728 | SCFH | Multiply by 472 | |

SLPM | Divide by 28.317 | SCIM | Multiply by 16.39 | |

SM³/MIN | Multiply by 35.31 | SLPM | Multiply by 1,000 | |

SM³/HR | Multiply by 0.5885 | SLPH | Multiply by 16.67 | |

NM³/MIN | Multiply by 37.99 | SM³/MIN | Multiply by 1,000,000 | |

NM³/HR | Multiply by 0.6331 | SM³/HR | Multiply by 16,667 | |

SCCM | Divide by 28,317 | NM³/MIN | Multiply by 1,075,785 | |

KG/MIN | Multiply by (29.39 ÷ SpGr) | NM³/HR | Multiply by 17,929 | |

KG/HR | Multiply by (0.49 ÷ SpGr) | KG/MIN | Multiply by (832,000 ÷ SpGr) | |

LBS/MIN | Multiply by (13.33 ÷ SpGr) | KG/HR | Multiply by (13,876 ÷ SpGr) | |

LBS/HR | Multiply by(0.2222 ÷ SpGr) | LBS/MIN | Multiply by (377,500 ÷ SpGr) | |

LBS/DAY | Multiply by (0.00926 ÷ SpGr) | LBS/HR | Multiply by (6,292 ÷ SpGr) | |

ACFM | Multiply by [[(Operating PSIG+14.7)(530)]÷ [(14.7)(Operating °F+460)]] |

**Step 2: Calculate Gas Correction Factor from given values**

**This information is required to size for conditions other than air at STP:**

Operating Temperature: _________°F

Operating Back Pressure:_________ PSIG

Specific Gravity of Gas: _________ @STP

Temperature Conversions | Gas Density Conversions | |||

From | To °Fahrenheit | From | To Specific Gravity | |

°Centigrade | (°C X 1.8) + 32 | LBS/FT³ | Divide by 0.075 | |

°Kelvin | (°K – 273.15)1.8 + 32 | KG/M³ | Divide by 1.2 | |

°Rankine | °R – 459.67 | MolWt | Divide by 29.0 | |

g/cm³ | Divide by 0.0012 |

Pressure Conversions | ||||

From | To PSIG | From | To PSIG | |

foot Water | Divide by 2.308 | Pa | (Pa÷101,300) X 14.7 | |

Inch Water | Divide by 27.73 | PSIA | Minus 14.7 | |

mm Water | Divide by 704 | ATM | (ATM X 14.7) – 14.7 | |

inch Hg | Divide by 2.036 | Torr | ((Torr÷760) X14.7) – 14.7 | |

mm Hg | Divide by 51.7 | Bars | ((Bars÷1.013) X14.7) – 14.7 | |

kg/cm² | Multiply by 14.228 | Millibar | ((Millibars÷1013) X 14.7) –14.7 | |

kPa | (kPa÷101.3) X 14.7 |

**Gas Correction Factor (GCF) formula:**

GCF = _________________

**Step 3: Determine the Air Equivalent Flow Rate.**

Air Equivalent Flow Rate = Customer Gas Flow Rate x Gas Correction Factor

Air Equivalent Flow Rate = ____________________

**Step 4: Calculate the maximum or minimum flow rate for the customer’s conditions (Customer Gas Flow Rate Scale)**

Customer Gas Flow Rate Scale = Catalog Flow Rate ÷ Gas Correction Factor

Customer Gas Flow Rate Scale = ______________________

**Liquid Flowmeter Sizing**

*Click Here To Download A Printable Version*

Variable area flowmeters suitable for liquid service have a capacity rating based on water at 70°Fahrenheit. Flowmeters

suitable for gas service have a capacity rating based on air at STP (70°F, 14.7 PSIA) conditions. The correction factors

listed below are used to calculate the flow capacity when using a liquid other than water or a gas other than air at STP conditions.

##### LIQUID CORRECTION FORMULA

*Water Equivalent Flow Rate = **Customer Liquid Flow Rate X Liquid Correction Factor*

Step 1: Convert *Customer Liquid Flow Rate* unit of measure to a standard unit of measure for water flow (GPM or CC/MIN).

Step 2: Calculate *Liquid Specific GravityCorrection Factor* from given values.

Step 3:* Determine the Water Equivalent Flow Rate from the product of the Customer Liquid Flow Rate and the Liquid Correction Factor.*Step 4: Calculate the maximum or minimum flow rate for the customer’s conditions.

**Step 1: Convert Customer Liquid Flow Rate unit of measure to a standard unit of measure for water flow.**

Customer Liquid Flow Rate ________________

Converted Gas Flow Rate _________________GPM / CC/MIN

Liquid Flow Rate Conversions | ||||

From | To GPM | From | To CC/MIN | |

GPH | Divide by 60 | GPM | Multiply by 3,785 | |

CC/MIN | Divide by 3,785 | GPH | Multiply by 63.08 | |

CC/HR | Divide by 227,100 | CC/HR | Divide by 60 | |

LPM | Multiply by 3.785 | LPM | Multiply by 1,000 | |

LPH | Multiply by 227.1 | LPH | Multiply by 16.67 | |

M³/MIN | Multiply by 264.2 | M³/MIN | Multiply by 1,000,000 | |

M³/HR | Multiply by 4.402 | M³/HR | Multiply by 16,667 | |

PINTS/MIN | Divide by 8 | PINTS/MIN | Multiply by 473.1 | |

FT³/MIN | Multiply by 7.48 | FT³/MIN | Multiply by 28,320 | |

FT³/HR | Divide by 8.021 | FT³/HR | Multiply by 472 | |

KG/MIN | Multiply by (0.264 ÷ SpGr) | KG/MIN | Multiply by (1,000 ÷ SpGr) | |

KG/HR | Divide by (227 X SpGr) | KG/HR | Multiply by (16.67 ÷ SpGr) | |

LBS/MIN | Divide by (8.347 X SpGr) | LBS/MIN | Multiply by (453.6 ÷ SpGr) | |

LBS/HR | Divide by (500.8 X SpGr) | LBS/HR | Multiply by (7.56 ÷ Spgr) | |

GMS/MIN | Divide by (3,785 X SpGr) | GMS/MIN | Divide by SpGr | |

GMS/HR | Divide by (227,000 X SpGr) | GMS/HR Multiply by 3.785 | Divide by (60 X SpGr) |

**Step 2: Calculate Liquid Correction Factor from given values**

**This information is required to size for liquids other than water:**

Specific Gravity of Liquid:____________ @ Operating Conditions

Liquid Temperature:__________°F @ Operating Conditions

Liquid Viscosity: _________cps @Operating Conditions

Specific Gravity of the Float to be used: ___________

Teflon | 2.20 | 316 SS | 8.04 | From | To Specific Gravity | |

Glass | 2.53 | Hastelloy C | 8.94 | LBS/FT³ | Divide by 62.4 | |

Sapphire | 3.99 | Carboloy | 15.00 | KG/M³ | Divide by 1,000 | |

Titanium | 4.50 | Tantalum | 16.60 | API | [141.5 ÷ (131.5+API)] | |

316L SS | 8.03 | g/cm³ | = SpGr |

**Liquid Specific Gravity Correction Factor (LSGCF) formula:**

**3. Determine the Water Equivalent Flow Rate
**

Water Equivalent Flow Rate = Customer’s Liquid Flow Rate ÷ LSGCF Water Equivalent Flow Rate = ______________________

**4. Calculate the maximum or minimum flow rate for the customer’s conditions. (Customer Liquid Flow Rate Scale) **

Customer Liquid Flow Rate Scale = Catalog Flow Rate ÷ LSGCF @ 70° F

Customer Liquid Flow Rate Scale = ____________________