Flow measurement

[Balkd]

Hi,

Is anyone know how to convert liters/minute to cubic feet/hour.
This is for natural gas application
Operating temp 18 degrees C
Amb temp - 75 degrees F
Differential pressure 950 psi
Size is 36 inch
Leakage is 68 liters/min
Thank
Daren

 

[DRWeig]

1 cubic foot = 28.32 liters
1 hour = 60 minutes

68 liters/min * 60 minutes / 28.32 liters/cf = 144 cf/hr

Unless I'm missing something...

Good on ya,

Goober Dave

 

[terje61]

1 liter = 0.0353 ft3
1 hour = 60 min.
Conclusion:
1 liter/min = 2.11888 ft3/hr
This is independent of the medium.

Since this question is too easy I am sure that this is not what you would really like to know.
Could you please detail your question?

Gr.
Terje

 

[vpl]

Googling "liter/minute" and "cubic feet/hour" will bring up hundreds of conversion websites. (actually, you may only have to start typing one of the terms to find a good website.

One that is frequently recommended is: Engineering Toolbox:

http://www.engineeringtoolbox.com.

Patricia Lougheed

******

Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of the Eng-Tips Forums.

 

[zdas04]

terje61,
As much as it doesn't look like it, your answer is one step away from being exactly the same number as DRWeig's number except his answered the question. Multiply 2.11888 times 68 and you get 144.08 l/hr.

David

 

[Balkd]

Hi Guys, thanks for the response, I know how to convert from liters to CF/H but I think i have to explain what am trying to accomplish.

The senerio is am checking for leakage thru a 36 inch cameron ball valve in the close position.

The valve is located on a discharge line from a compressor which is attached to a RB 211.

every time the unit is pressurize the valve opens and when unit shuts off the valve closes, the trap gas upstream of the valve is then depressurze and the downstream pressure remains pressured up at 950 psi. The temparature increases when the unit is in operation.

The meter that am using measured in decibels then entered into a leakage calculation by the manufacture and gives the end results in liters/min.

My question how can i convert liters/min or hour to CF/H taking the process into consideration, would i need to include the compressability factors,molecular weight of gas etc to give me to leakage of should i just go from converting the liters to cf/h as you all mentioned.

thanks very much
DB

 

[terje61]

Hello Balkd,

The problem with gasflow is that it is often unclear for the external party (you and me) to see what kind of flow is applicable.
- Is this the actual flow (at actual pressure/temperature)?
- Is this normal flow (at 1 bara/0°C)
- Is this standard flow (at 1 bara/15°C)

Now we even have two problems.
1) I do not know what your meter measures
2) I do not know what answer you are looking for

Conclusion:
- Please verify the documentation of the flow meter. Most flow meters provide information regarding actual flow (unfortunately not all)
- In case the meter output and your required answer both have the same unit (actual OR normal OR standard flow). You can do the simpler conversion. If not you have to include the pressure, temperature, compressibility and density factors as well.

Rgs,
Terje