Randall,
For a horizontally mounted engine, it is likely that if you pour fuel in
the end of the engine that it will also back up into the oxidizer
injector holes, depending on their position. Is a gaseous purge really
enough to clean out all traces of hydrocarbon in those lines? It must
work since you're suggesting it (and using it) but it seems like there
could still be some fuel left in the lines afterwards. How long of a
purge do you use?
-Bob
On 04/25/2016 05:42 PM, Randall Clague wrote:
Easy to test, too. Load fuel. Do not load LOX. Disconnect igniter power. Disconnect LOX Pre and LOX Main, because Murphy. Cold flow fuel. Safe the stand. Pour fuel into chamber until it runs out the throat. Return to bunker. Purge. Safe the stand and inspect the chamber.
If you want to be extra conservative, test with a liquid of higher viscosity than your fuel.
Check your LOX system for fuel contamination afterward. Not because there's any reason to believe there is any, but because if there is, this is a good opportunity (fewer variables than usual) to find it and isolate it.
-R
