I called a friend still in the business. He's not been an operator for decades, but he specs the following: Kero/JetA: 110-120F #2 Heat 120F #2 Diesel >120F, he recalls 125 but won't swear to that number. That said, the military had their own brews. USAF used to use nasty JP4, it being laced with tolune and naptha. The Navy would not touch the stuff, not wanting low flash stuff inside a carrier. They used JP5, which ISTM is higher temp JetA. The AF has since wised up and gone to JP8, which I believe is almost identical to JetA. Exception {past} -- the Blackbird used JP7, much thicker {"3 in 1 oil" feel, I'm told.} and higher flash. In any case, there is no practical difference in a building tank housing any of the top three. Regarding the pressure difference issue.... The tank by the generator [aka "day tank"] is filled from below. If you have a 30 story building, with a roof generator, that's ~~150psi. If the line ruptures on floor 3.... One approach is coaxial lines: the inner is the high pressure "up" line; the outer the overflow return. If the inner ruptures, it will be into the outer.... -- A host is a host from coast to coast.................wb8foz@nrk.com & no one will talk to a host that's close........[v].(301) 56-LINUX Unless the host (that isn't close).........................pob 1433 is busy, hung or dead....................................20915-1433