i become confuse when calculating the pump NPSHa. one of the factor that we need to consider is the source pressure i.e. let say the LPG bullet tank operating pressure 10 barg, in order to have figure in head (m), do i need to convert to bar absolute first? which is becomes 11.01325 bara than convert to head? or just straight convert 10 barg to meter head?
let say just convert it using gauge pressure, does it means that ATM tank will be having 0 meter head in term of source of pressure?