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[vr1]

Hi,

Has anyone used Annex D of the new API 2000. Annex D says the way to convert from STP to NTP and vice versa. Especially Eq D 37.

 

Thanks,

Vr

[vr1]

After going through a lot of previous posts in cheresources, my understanding is that Grahams law of Effusion is only when the two gases (Blanketing gas and Air) are at the same conditions.

 

We have to use

 

ACFH = SCFH * (Pstd/Pact)*(Tact/Tstd)*(Zact/Zstd)

 

for converting Blanket gas (Nm3/h) to Air (Nm3/h).

 

qair = x / Mair * Wfl * SQRT ( Mair * Ti / Tair * M).......D37

 

One person has used Annex D Eq 37 for converting am3/h of blanketing gas (80 C, 1 kPag) to Nm3/h of air. As the blanketing gas is Fuel gas with MW - 16.4, Density at tank operating conditions - 0.5 kg/m3, the volumetric flowrate calculated using the above Eq is very low.

 

If any of the experts can tell me if this is the right way of doing it, I would appreciate it.