Moose fuel tanks/Water Condensation?
Posted: Fri Feb 17, 2012 10:04 pm
I have been flying my Rebel for almost 2 years now, and have never seen even
a drop of water in my fuel. I never store my tanks full, usually 1/2 or
less, and it is sometimes idle for weeks at a time in the winter. Last year,
it was idle for 5 months (being repaired) in one stretch. I live in the
soggy Northwest (Vancouver BC), but my plane is always hangared. I use mogas
most of the time, but avgas occasionally.
So, just wondering how big this problem really is. What is the experience of
others? Have you actually got water in your fuel from condensation in your
tanks?
-----Original Message-----
From: murphy-rebel@dcsol.com [mailto:murphy-rebel@dcsol.com]On Behalf Of
Mike Davis
Sent: Thursday, April 11, 2002 6:52 AM
To: murphy-rebel@dcsol.com
Subject: Re: Moose fuel tanks
Hi Bob, I had not thought about expansion on the inboard tanks, but had
considered plumbing the ram air into both tanks and placing a small valve on
the inboard tank that could be turned off (shut of the vent) when using the
outboard tanks... this would take care of pressure normalization. As for
ram air alone moving the fuel from outboard to inboard, my thought was that
the ram air only has to help since the system would still work as a gravity
based system as fuel was burned out of the inner portion... I see what you
mean though if the inboard was full it would be working against gravity
after a while. I thought my uncle's tip tanks on his Comanche transferred
using pressure only, and I know he burns those off first, while the tank
they transfer to remains full... I'll have to check with him and see for
sure how those work.
Water condensation is the main reason I'm interested in separate tanks... it
would be much worse with one big tank if I didn't keep it full. The
outboard portion of the tank would need it's own pencil drain of course, but
again long range tanks are fairly common on a lot of aircraft and I'm not
aware of any increased tendency for water collecting in the tanks when
empty.
One of the local builders has two separate tanks in each wing, but he ran
separate plumbing from each into the cabin, and then has two small valves
mounted in the cabin in each wing root to turn them on and off, then runs
them both down the same line into the cabin to a central andair selector on
the floor. I'm not sure what he is going to use for a quantity indicator on
the outboard tanks. I was hoping for something simpler than this though.
Thanks, Mike
195SR
----- Original Message -----
From: "Robert Johnson" <ob.johnson@sympatico.ca>
To: <murphy-rebel@dcsol.com>
Sent: Thursday, April 11, 2002 4:31 AM
Subject: Re: Moose fuel tanks
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a drop of water in my fuel. I never store my tanks full, usually 1/2 or
less, and it is sometimes idle for weeks at a time in the winter. Last year,
it was idle for 5 months (being repaired) in one stretch. I live in the
soggy Northwest (Vancouver BC), but my plane is always hangared. I use mogas
most of the time, but avgas occasionally.
So, just wondering how big this problem really is. What is the experience of
others? Have you actually got water in your fuel from condensation in your
tanks?
-----Original Message-----
From: murphy-rebel@dcsol.com [mailto:murphy-rebel@dcsol.com]On Behalf Of
Mike Davis
Sent: Thursday, April 11, 2002 6:52 AM
To: murphy-rebel@dcsol.com
Subject: Re: Moose fuel tanks
Hi Bob, I had not thought about expansion on the inboard tanks, but had
considered plumbing the ram air into both tanks and placing a small valve on
the inboard tank that could be turned off (shut of the vent) when using the
outboard tanks... this would take care of pressure normalization. As for
ram air alone moving the fuel from outboard to inboard, my thought was that
the ram air only has to help since the system would still work as a gravity
based system as fuel was burned out of the inner portion... I see what you
mean though if the inboard was full it would be working against gravity
after a while. I thought my uncle's tip tanks on his Comanche transferred
using pressure only, and I know he burns those off first, while the tank
they transfer to remains full... I'll have to check with him and see for
sure how those work.
Water condensation is the main reason I'm interested in separate tanks... it
would be much worse with one big tank if I didn't keep it full. The
outboard portion of the tank would need it's own pencil drain of course, but
again long range tanks are fairly common on a lot of aircraft and I'm not
aware of any increased tendency for water collecting in the tanks when
empty.
One of the local builders has two separate tanks in each wing, but he ran
separate plumbing from each into the cabin, and then has two small valves
mounted in the cabin in each wing root to turn them on and off, then runs
them both down the same line into the cabin to a central andair selector on
the floor. I'm not sure what he is going to use for a quantity indicator on
the outboard tanks. I was hoping for something simpler than this though.
Thanks, Mike
195SR
----- Original Message -----
From: "Robert Johnson" <ob.johnson@sympatico.ca>
To: <murphy-rebel@dcsol.com>
Sent: Thursday, April 11, 2002 4:31 AM
Subject: Re: Moose fuel tanks
tankNot being an expert, this is what I see could be a problem. 1/ I doubt you
would get enough ram air pressure to force the outboard tank empty while
still maintaining a quantity of fuel in the inboard. 2/ If the inboard
inonly is full, and sealed with the check valve like you describe this means
there is no vent in this tank and what do you think would happen sitting
wouldthe hot sun ??? 3/ If the outboard tank was empty a lot of the time, I
ofbe concerned about condensation (water) build up when sitting, and this
would be the first thing sucked into the inboard tank when running. ( if
thecourse you had enough suction to open the check valve without collapsing
*-------------------------------------------------------------------------*wing section first.) Just MHO -Bob J Rebel "652"
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