Do you pump your UAT dry ?
12-10-2008 | 10:30 PM
#5
RE: Do you pump your UAT dry ?
NEVER!
I pull them out of the bag and put fuel in them even before they get installed and shake them and roll them in all directions. One of the biggest unknowns in turbines is "How did that bubble get through the UAT?" Usually it's because the air was not properly purged to begin with. If the UAT is empty it is either because the bird is out of fuel or it has augered in...............
Tailwinds,
John
I pull them out of the bag and put fuel in them even before they get installed and shake them and roll them in all directions. One of the biggest unknowns in turbines is "How did that bubble get through the UAT?" Usually it's because the air was not properly purged to begin with. If the UAT is empty it is either because the bird is out of fuel or it has augered in...............
Tailwinds,
John
12-10-2008 | 11:11 PM
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From: Bemis,
NM
RE: Do you pump your UAT dry ?
ORIGINAL: George
No, leave it full. If you want to drain your tank/s, do it from the UAT fill line and it will draw all the fuel from your tanks while leaving the UAT full.
George
No, leave it full. If you want to drain your tank/s, do it from the UAT fill line and it will draw all the fuel from your tanks while leaving the UAT full.
George
12-10-2008 | 11:21 PM
#8
My Feedback: (24)
RE: Do you pump your UAT dry ?
Also, if you mount the UAT at an angle with the fill lines on the top corner, the fuel will stop coming out of the UAT as soon as the fuel stops coming from the main tanks and it will not pull the UAT down far enough that the filter "bag" is exposed out of the fuel.
Bob
Bob
12-10-2008 | 11:25 PM
#9
My Feedback: (57)
RE: Do you pump your UAT dry ?
ORIGINAL: Ed
But George, won't using the UAT fill line also empty the UAT ?
ORIGINAL: George
No, leave it full. If you want to drain your tank/s, do it from the UAT fill line and it will draw all the fuel from your tanks while leaving the UAT full.
George
No, leave it full. If you want to drain your tank/s, do it from the UAT fill line and it will draw all the fuel from your tanks while leaving the UAT full.
George
Suck the fuel out using the fill line and you will see. NOW, if you drain from the pick-up (the line feeding the fuel pump), that will drain the UAT; this may be where you are getting confused. I hope I didn't confuse you more.
George
12-11-2008 | 12:03 AM
#10
My Feedback: (2)
RE: Do you pump your UAT dry ?
never - barring exceptional circumstances such as rebuilding it, or moving it to another plane, or taking it on a plane to a jet rally...
Now there are some hopper tanks that have a center pickup, and no filter bag...those you can drain if you want to...but the BVM style ones, leave the fuel in!
Now there are some hopper tanks that have a center pickup, and no filter bag...those you can drain if you want to...but the BVM style ones, leave the fuel in!
12-11-2008 | 12:03 AM
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From: Bemis,
NM
RE: Do you pump your UAT dry ?
OK, thanks guys. I had to sketch the UAT out on paper to better understand it. 
It appears that both the tank and fill line fittings are at the top of the container, and above the fuel level inside. Whereby the line feeding the pump comes from the filter element and remains submerged. So if I continue to crank the tank completely dry, and suck air, the membrane in the UAT should remain submerged, since the suck line fitting is at the top, and above the fuel level in the UAT. It will be sucking air from the tank, and not the UAT. Using the fill line to suck fuel from the tank, makes it seem impossable to ever empty the UAT. I think this is what George is saying, but saying better. 
Thanks for helping out this newbie.
It appears that both the tank and fill line fittings are at the top of the container, and above the fuel level inside. Whereby the line feeding the pump comes from the filter element and remains submerged. So if I continue to crank the tank completely dry, and suck air, the membrane in the UAT should remain submerged, since the suck line fitting is at the top, and above the fuel level in the UAT. It will be sucking air from the tank, and not the UAT. Using the fill line to suck fuel from the tank, makes it seem impossable to ever empty the UAT. I think this is what George is saying, but saying better. Thanks for helping out this newbie.
12-11-2008 | 12:05 AM
#12
My Feedback: (2)
RE: Do you pump your UAT dry ?
never - barring exceptional circumstances such as rebuilding it, or moving it to another plane, or taking it on a plane to a jet rally...and they get thoroughly purged afterwards.
Now there are some hopper tanks that have a center pickup, and no filter bag...those you can drain if you want to...but the BVM style ones, leave the fuel in!
Now there are some hopper tanks that have a center pickup, and no filter bag...those you can drain if you want to...but the BVM style ones, leave the fuel in!
12-11-2008 | 12:38 AM
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From: Longwood ,
FL
RE: Do you pump your UAT dry ?
Ed,
BVM has the best instruction manuals and insrtruction sheets in the business.
On the UAT instruction sheet, side 2, there is a paragraph entitled: Defueling-
Quote: "If it your normal practice to defuel the model at the end of the day, leave the fuel in the UAT for easiest next sttart-up procedure. Of course, if the model is to be air transported drain all of the fuel system completely."
Also, the instructions show mounting position information, fueling procedures, first engine start, posat flight checks and additional operating tips.
BVM has the best instruction manuals and insrtruction sheets in the business.
On the UAT instruction sheet, side 2, there is a paragraph entitled: Defueling-
Quote: "If it your normal practice to defuel the model at the end of the day, leave the fuel in the UAT for easiest next sttart-up procedure. Of course, if the model is to be air transported drain all of the fuel system completely."
Also, the instructions show mounting position information, fueling procedures, first engine start, posat flight checks and additional operating tips.
12-11-2008 | 07:08 AM
#14
My Feedback: (57)
RE: Do you pump your UAT dry ?
ORIGINAL: Ed
OK, thanks guys. I had to sketch the UAT out on paper to better understand it. It appears that both the tank and fill line fittings are at the top of the container, and above the fuel level inside. Whereby the line feeding the pump comes from the filter element and remains submerged. So if I continue to crank the tank completely dry, and suck air, the membrane in the UAT should remain submerged, since the suck line fitting is at the top, and above the fuel level in the UAT. It will be sucking air from the tank, and not the UAT. Using the fill line to suck fuel from the tank, makes it seem impossable to ever empty the UAT. I think this is what George is saying, but saying better.
Thanks for helping out this newbie.
OK, thanks guys. I had to sketch the UAT out on paper to better understand it.
It appears that both the tank and fill line fittings are at the top of the container, and above the fuel level inside. Whereby the line feeding the pump comes from the filter element and remains submerged. So if I continue to crank the tank completely dry, and suck air, the membrane in the UAT should remain submerged, since the suck line fitting is at the top, and above the fuel level in the UAT. It will be sucking air from the tank, and not the UAT. Using the fill line to suck fuel from the tank, makes it seem impossable to ever empty the UAT. I think this is what George is saying, but saying better. Thanks for helping out this newbie.
You got it Ed. Good luck.
George
