# Gas flow units MSCMD, KM^3 and SM^3x10

1. Jul 4, 2012

### rolls

Is kM3/d 1000 m^3 a day or a kilometre^3 a day?

I know it should be little m but this is what is written on our gas measuring instrument

Are the units kM3/day 1000 cubic metres per day, or a kilometre cubed per day eg 1000x1000x1000 m^3 = 1e9

Thanks

Last edited: Jul 4, 2012
2. Jul 4, 2012

### MrSid

Take a look back, and compare the size of pipes going into the gas meter and where the gas is going to get a reality check for your two versions....

If this is a low pressure gas main going to a burner, convert the volume per unit time to the linear velocity of gas through one meter of pipe; for cubic kilometers of gas per day, the 10E09 cubic meters can be determined to still be an absurdly large amount of gas per second...
(over 150,000 cubic meters per second!!!!). Even with a pipe with a cross section of 1 square meter, the linear velocity bogles the mind for low pressure gas passing across one meter. It would scream!!! not to mention what it means in terms of smaller pipe diameters likely to be found feeding the gas meter.

Also think if this is CH4 feeding a burner, how many moles of gas and therefore how many moles of air need to be available to combust the gas.... The heat value, mass balances, and CO2 evolved per unit time could also be points for reality checks....

3. Jul 4, 2012

### rolls

Yeah that was what I was thinking, a km^2 is just a ridiculous amount of gas.

Thanks.