I do not know what your application is but you may not want to forget about the energy required to heat up the mass of the vessel. This is often very significant.
Carl
It looks like this thread is a bit old but Arsef's post is pretty recent.
Arsef's response is the preferred solution. In general, sanitary systems, Ambient WFI, Hot WFI, RO, etc have a looped distribution system. This is to prevent system contamination and biofilm formation. All dead-legs...
Are you actually measuring the pressure in the two bottles or just performing a squeeze test? The larger bottle generally feels softer because of its geometry...hmm I have a couple 0-20 digital pressure gauges in my garage. Did you try having a spare 2L bottle and transferring the remaining 1L...
Maybe I can pick up on something else in his post. Is the 2.5-in pipe heat exchanger direct injection heating or indirect? 7-bar sounds high to me for a heating application. Can anybody comment?
Carl