Rowland,
I don=92t see any expansion of the fuel tank on top. Typically, in my pers
onal work, I use a =BD inch, 13mm, blue foam for a top tank spacer so the t
ypical 3/8=94x =BC=94) 10mm OD 8mm ID hose fits well and is replaceable. I
n one aircraft we reconstructed, the tank was flush with the top of the mod
ule. So going through the headrest was the only solution.
I've accomplished my mod many times. The new tank doesn't expand that much
around any side in my opinion. If you have room over the top of the tank
for the line, feel free to go over the tank. Problem with over the tank is
the fuel that eventually gets trapped in the sight gauge vent area above t
he tank when refueling does not drain down to the bottom and the fuel level
is inaccurate. Any fuel in the sight gauge upper portion reduces the leve
l in the lower portion obviously. In my operations, I carry a piece of sil
icon =BC ID tube to fit in my filler neck that easily connects to the sight
gauge tee located easily to reach through the gas cap and I blow through t
he line to force the fuel out of the upper part that spilled into it during
refill and bubble over. I have many years of this sight tube clearing in
N12AY and a reasonably accurate sight gauge. It bounces a little in flight
because I didn=92t bother putting in an FS02. I took it out so I could se
e the fuel bouncing making it easier to see the movement rather than pickin
g out the steady little line of fuel. Another issue I personally have is m
y sight gauge goes down the center of the aft console and past my map case
and I needed to put a light strip behind the tube to see it down to the bot
tom when I open my map case top and view through the clear plexiglass . (T
rust me, more work than was needed, but it keeps the cockpit tidy and the l
ight is a help seeing the fuel level.)
To spare other aircraft owners from having to blow through the vent tube to
get the fuel sight gauge clear, I now run the fuel vent from the upper cob
ra, down and into the headrest from the door and angled down through the he
adrest top and then poke out and down the passenger cushion left side to th
e bottom. I run the tube in aluminum or copper (easier to put sweat fittin
gs on) and put a fitting on the top and bottom of the sight gauge for quick
clear tube change out. Make a neat fiberglass tube chase and even a small
light strip behind it with appropriate graduations makes it tidy is quite
handy.
In my aircraft the tube on the top of the tank area does not get changed ou
t. I put a fitting on the tube exiting the top of the tank. The only area
I need replace is then from the fitting on the upper section down to the f
uel boss on the pilots side. The issue then is fittings. I=92ve used safe
ty wire wraps mostly, but clients have changed that out for a zip tie or sp
ring clamp. To each his own.
Tubing types varies for the sight gauge. They all yellow with age but am f
inding a newer clear tubing to be better (but not perfect). Aircraft Spruc
e P/N: 05-01063 3/8=94 OD, =BC=94 ID
As for running the vent line, ideally, a hole in the front top of the tank
and one in the bottom is the best solution but, lets face it, who wants to
drill another hole in the tank and assume it won't leak, EVER. So I fit it
to the cobra and then to the pilots side drain line.
In my various work done on retrofitting aircraft we have done variations on
the basic vent theme:
See attachment A sight gauge that really works in word format. Which was s
ubmitted as a tech talk.
For those with over the top vents or just room to really loop the vent line
over the top from the cobra is another variation.
[Diagram Description automatically generated]
Do not forget to calibrate your sight gauge and consider making the install
ation as maintainable as possible. I do not put a quick disconnect on my s
ight gauge for rapid changeout. If I need to change the sight gauge, I sim
ply do it when I can drain the tank. That way there are fewer fittings to f
ool with.
Best Regards,
Bud Yerly
-----Original Message-----
From: owner-europa-list-server@matronics.com <owner-europa-list-server@matr
onics.com> On Behalf Of Rowland Carson
Sent: Saturday, July 31, 2021 11:08 AM
Subject: Europa-List: fuel tank expansion question
mailto:rowlandcarson@gmail.com>>
I=92m running my fuel sight gauge up the back of the starboard seat. The tu
be then has to go aft towards the vent. One could run it across the top sur
face of the cockpit module adjacent to the headrest. But there is quite a d
ecent space between the top of the tank and the undersurface of the cockpit
module, so I=92d like to take the tube across the area between the headres
ts in that space. That seems a neat and tidy way to keep the tube out of th
e way. However, I understand that contact with fuel makes the tank swell up
. I=92m concerned that the tank, once filled with fuel, will expand so much
that it will crush the tube and close the vent to atmosphere.
Does anyone have any idea of how much the tank expands vertically? Will it
swell until it touches the underside of the cockpit module?
In this connexion, it occurs to me now that the flange of the analogue fuel
level sender might also foul the underside of the ply floor in the starboa
rd headrest if the tank swells a lot. I think I made the hole in the ply fl
oor just big enough for the top part of the sender, not the flange. Has any
one experienced any issues with that?
All information on the topic welcome.
in friendship
Rowland
Europa 435 G-RODO
| Rowland Carson ... that's Rowland with a 'w' ...
| <rowlandcarson@gmail.com<mailto:rowlandcarson@gmail.com>> http
s://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.rowlandca
rson.org.uk%2F&data=04%7C01%7C%7C236a3a23033b4fdc6fa608d95435b665%7C8
4df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637633411938983532%7CUnknown%7CTW
FpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3
D%7C1000&sdata=SWnoXInRfUKH415oyYu41kkySg3h2KCr4A1B2t3hNSc%3D&res
erved=0
| Skype, Twitter: rowland_carson Facebook: Rowland Carson
%2Fwww.matronics.com%2FNavigator%3FEuropa-List&data=04%7C01%7C%7C236a
3a23033b4fdc6fa608d95435b665%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C6
37633411938993528%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luM
zIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=V9%2FPncB9kxa74D5MV%2F
MAoDew2zyfmywdtB1CTykn2fk%3D&reserved=0
%2Fforums.matronics.com%2F&data=04%7C01%7C%7C236a3a23033b4fdc6fa608d9
5435b665%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637633411938993528%7C
Unknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiL
CJXVCI6Mn0%3D%7C1000&sdata=eAIaZMmh5wpKOWmz3luCwiQ1CO%2FaSKevyzzjIW3L
niw%3D&reserved=0
%2Fwiki.matronics.com%2F&data=04%7C01%7C%7C236a3a23033b4fdc6fa608d954
35b665%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637633411938993528%7CUn
known%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJ
XVCI6Mn0%3D%7C1000&sdata=zcED3BL%2Ftg2%2FVgfq1BHKeXd3Ee%2BiVtxpLhWpxZ
PNjTU%3D&reserved=0
%2Fwww.matronics.com%2Fcontribution&data=04%7C01%7C%7C236a3a23033b4fd
c6fa608d95435b665%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637633411938
993528%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6
Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=YAe0YZcXNai1bVM2KwJhTukHHNGan5bZC
MhUaVnSo%2Fo%3D&reserved=0
|