Fuel vents
Posted: Sun Feb 19, 2012 10:39 am
I've been at S & F for the last week and having just returned to a bunch of e-mails regarding fuel venting - thought I'd throw in my 2 cents worth of experience with N96CS. (Didn't see a single Murphy at S&F)
I have the flush non-vented flush caps that came with the kit and I am using capacitance type fuel probes - thus no site gages - and have both tanks vented with a fitting at the top most point in the root rib of each. Of course this means that the actual vent line is about 1/2" below the top of the tank due to the attaching plate fitting. Both vent lines then run to a common inverted J tube above the fuselage (aluminum lines). The problem with this is that when a tank is full, the vent line is under fuel. With temperature expansion, fuel is then forced out the vent until the vent becomes uncovered.
I found it was necessary to vent the caps with an inverted J tube to correct this problem. I did weld small flanges on the caps so that they can be turned by these flanges rather than having someone grab the J tube. Seems to work fine.
Charlie Starr SR #065
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I have the flush non-vented flush caps that came with the kit and I am using capacitance type fuel probes - thus no site gages - and have both tanks vented with a fitting at the top most point in the root rib of each. Of course this means that the actual vent line is about 1/2" below the top of the tank due to the attaching plate fitting. Both vent lines then run to a common inverted J tube above the fuselage (aluminum lines). The problem with this is that when a tank is full, the vent line is under fuel. With temperature expansion, fuel is then forced out the vent until the vent becomes uncovered.
I found it was necessary to vent the caps with an inverted J tube to correct this problem. I did weld small flanges on the caps so that they can be turned by these flanges rather than having someone grab the J tube. Seems to work fine.
Charlie Starr SR #065
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Unsubscribe: rebel-builders-unsubscribe@dcsol.com
List administrator: mike.davis@dcsol.com
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