Ian Woollard wrote: > "Apart from the thermal stress and other problems of dealing with cryogens, it is >difficult to keep oxygen from > reacting with the walls of the plumbing it is flowing through. This makes it >extremely difficult if not absolutely > impossible to eliminate catastrophic failure modes, in which a failure in one engine >destroys the entire propulsion > system." > > I was wondering whether HTP was quite so bad for this kind of failure mode. Will >wall material > burn as easily in HTP if you get it hot enough by losing a pump? Does one engine >necessarily take all the > others out? Is the above statement even true for LOX? (He does mention some alloys >don't do this, but > they're supposedly heavy.)
Well, I don't think it's quite that bad for LOX, although GOX at extremely high pressures ( >3000 psi or so ) gets to be a bit touchy - the NASA oxygen safety manual mentions things like sonic gas flow compression heating, particle impact ignition, potential kindling chain propagation, and the importance of preserving oxide films against abrasion. For LOX service, as compared to HP-GOX, it doesn't seem to be _quite_ as critical to "precision clean" off all tiny little foreign particles, machining dust, etc., though it is still of course very important to remove all traces of combustible surface film (oil, etc). Keeping high-pressure oxygen in a steel container is about like keeping HTP in a polyethylene one... it's stable enough under ordinary circumstances but the combination could in some potential circumstances be ignited. (The oxygen safety brochure included in my Swagelok catalog binder gives a firm warning with respect to designing oxygen plumbing: "seek expert professional assistance".) -dave w _______________________________________________ ERPS-list mailing list [EMAIL PROTECTED] http://lists.erps.org/mailman/listinfo/erps-list
