Dear Sir,
Kindly consider Nm3 as the moles supplied.
They will remain constant.
Only the actual volumetric flow rate will change.
For example,
1 pound mole = 379 Standard ft3
Standard ft3 means at 1 atm and 60 Deg. F
Similarly Normal ft3 means at 1 atm and 32 Deg. F.
Kind Regards...