I'm trying to get the mass flow rate through a regulator (LT Gasetechnik 370100) from a LN2 storage tank, for sizing a PSV. Unfortunately the third party that provided the regulator is not being very helpful and the supplier is German, making support a bit difficult. The only data I have is the German manual, which fails to mention a Cv. It does however list Max. Leistung, which google reliably informs me is max capacity, as:
p2/p1 < 0,5:
bei p2=40 barü:
or as google translate puts it:
at p2 = 40 barg:
2100 Nm ³ / h
So if anyone could help interpret how to get my flow from this information it would be very helpful. If it listed this flow as at a specific upstream pressure I could just adjust the flow for the altered density depending on my actual upstream pressure, but I'm not sure how the downstream pressure in choked flow is useful to me. My upstream pressure is max 1929kPag. My downstream pressure is going to be the PSV set point at 750kPag.
Any help would be much appreciated.
PS: there is a vaporiser between the LN2 storage and the regulator so phase is going to be gaseous, not liquid.