4 replies to this topic

[mesbah]

Hello everyone,

I’m looking to calculate the number of single nitrogen cylinders required to carry out a leak detection test on pipe(volume of 14m3)

The leak test pressure is 1485 psig

Nitrogen cylinder -> 6m3 / 2175.5psi

I’m struggling with the fact the bottles will begin to equalize with the test segment meaning it’s not as simple as I first thought. I believe I need to calculate how much gas is in a cylinder between the delivery and test pressure (useable volume)

Any help would be appreciated.

Many Thanks

[latexman]

Don't colored your post, this makes the reading difficult.

 

Show/attach your work.  Have you tried the ideal gas law, PV = nRT?

[breizh]

Hi, Pagi 'Bu

Agree with latexman , I did the calculation using the perfect law gas PV=nRT 

My calculation is 3 full receivers of N2 and 32 %mass of the 4th one.

Calculation is based on initial condition vs final condition.

To visualize the process, consider a tank with N2 and the pipe, in between a valve (open or close) during the test leak.

My assumptions.

Isotherm process, Initial condition, pipe full of air at Patm , Air # N2 (no impact on the test).

driving force is the pressure meaning P bottle >or equal to Pressure in pipe .

At the end of each step, you have remaining product in the bottle!

 

End of the test when P= 1485 PSIg 

 

 

 

 

Good luck

 

Breizh

Attached Files

•  nitrogen leak test.xlsx   13.95KB   6 downloads

[breizh]

Hi,

EDIT : 

Right now I'm confused with the capacity of the nitrogen cylinder .... 

Are you sure about 6 or 7 m3 ? 

It seems that 1 cylinder is about 50 liters per unit at 145 bars equivalent to 7 m3 at 1 atm.

Please confirm your input.

https://survitecgrou...r_datasheet.pdf

 

With a 47 liters cylinder @ 151 bars A , you will need 343 cylinders to perform the test ! 

same methodology for the calculation, only volume of cylinder changes.

If confirmed , better to buy Skid or cage with 6 bottles per unit.

Breizh 

Attached Files

•  nitrogen leak test.xlsx   56.02KB   5 downloads

[breizh]

Hi,

No feedback from the OP!

Breizh