Flush fuel drains

[TShort]

Has anyone seen these?
Check flymore.com.au under flush fuel drains.
I'm sure this wouldn't reduce drag THAT much, but I kind of like the idea of not having so much hanging out below the wing.

T.

[Bob Axsom]

Several times I have had "dripping drains" that I have been able to stop because I can grab the center piece and move it to get full closure. Otherwise I would consider them too. You are still going to have the wrenching head sticking out there in the wind so it does not eliminate the drag.

Bob Axsom

[Mel]

A possible dissadvantage I see is that they seem to project further up into the tank, thereby not catching contaminates in the very bottom of the tank (which is where water will be).

[osxuser]

Those look just like the ones that amost all cessnas use... they work fine!

[TShort]

Originally Posted by Mel

A possible dissadvantage I see is that they seem to project further up into the tank, thereby not catching contaminates in the very bottom of the tank (which is where water will be).

I thought that too - but it looks like they may have holes right where the bottom of the tank would be to catch that stuff... ?

Thomas

[gmcjetpilot]

Originally Posted by TShort

Has anyone seen these?
Check flymore.com.au under flush fuel drains.
I'm sure this wouldn't reduce drag THAT much, but I kind of like the idea of not having so much hanging out below the wing.

T.

I have these but they are standard drain parts and can be bought by any of the good airplane supply folks. "Flymore" tends to want way to much for stuff. I don't have the part number but its the standard 1/8 npt type. They retail for $18 each. If you have the ones in the kit you can sell them or may be able to trade them, they cost the same. My guess is they are SA18's: http://www.aircraftspruce.com/catalo...afairflush.php


Just be aware there is MORE of the drain valve sticking up inside the tank with this style, so you have to watch your fuel pickup or if you have a flop tube.

Also keep in mind the aluminum flange on the bottom of the tank sticks out a little good bit. The drain valve sits on top of the tank's threaded flange, so there is still height, so its not really flush. I am using a "semi-flush" valve and a little fairing as well.


You can buy pre made fairings now for the original taller drain valve; you could just pro-seal them on.http://www.aircraftextras.com/FuelDrainFairings.htm


One other small difference is the "semi flush" or "cessna" drain, is that it needs a sump cup with the pin to insert into it. No big deal, but with the button or bayonet type you can use almost anything to drain fuel. I still like the semi-flush. I have heard rumor or urban legend that the flush type is easier to block? I don't know about that. If you have to remove it and clean it fine, but one dude at the flight club got the drain stuck on!!!!! It was a mess. No fire but lots of fuel on the ramp. It was like the little boy with his finger in a hole in the leaking dam. Not good. I don't recall what type of drain valve it was.

I assume they both "SUMP" the same, that is the fuel drains at the same level. It looks lower with stock valve? Its probably even or good enough. I just found the the fuel pick up crowded the new style semi-flush valve a little. Van's I think are CAV-110's, you can see it does not proturde into the tank and may drain lower in the tank:


Another brand that might work? MDI's F391-18:

[ccrawford]

Is there any reason you couldn't shorten the SA18's so they don't stick into the tank as far?

[jarhead]

Originally Posted by ccrawford

Is there any reason you couldn't shorten the SA18's so they don't stick into the tank as far?

Yes - it wouldn't work anymore.

The upper "housing" that projects into the tank contains the valve poppet, and the spring that holds it closed. No housing=no spring.

[chaskuss]

Originally Posted by TShort

Has anyone seen these?
Check flymore.com.au under flush fuel drains.
I'm sure this wouldn't reduce drag THAT much, but I kind of like the idea of not having so much hanging out below the wing.

T.

Thomas,
I'm not using the ones you show. Mine are more aerodynamic. They are used on Beech King Airs. They don't have a hex shape exposed to the airstream. The outer edge tapers down to almost nothing. They use a spanner wrench for installation & removal them. I had to shorten my flop tube by 1" to ensure clearance. They can be disassembled and rebuilt easily, as they contain only 2 sealing O-rings. They drain all the way to the bottom of the tank. One advantage they DO have is that you can lock them in the open position. This is a handy feature if you ever have to drain contaminated fuel from the tanks.
Photos of my installation can be found on the thread linked below:

http://www.vansairforce.com/communit...ight=flop+tube

Charlie Kuss