Hi Nigel, thanks I had a look at your link and get the jist tho maths was never my strong point at school (history was always my forte ☺) so alot of the equations kinda went over my head! What I'm wondering, in layman terms (or dumbed down lol!) Is can the stansted DTB5C be run from a couple of 15s? I don't have my own compressor but do have access to one which I could use to fill the 15s so I could then run the booster at home rather than having to run back and forward to the compressor (round trip of approx 70 miles). Alternatively if run off a LP compressor, what sort of size would be required? And also someone had mentioned a water separator, could this be explained further please?