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A good amount of big boy aerospace industry people will claim that collegiate teams are not capable of having a cleaning standard high enough to prevent FOD clogging of a 10 thou gap annulus (and will thus advise against a pintle or suggest some weird variants of it), but we found that flushing the system with water multiple times (without it hooked up to the injector) has resulted in very clean water flows. At this point, however, we are more concerned about FOD generators (i.e. chattering check valves) but this hasn't caused a real problem for us yet.
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