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fklein(at)orcasonline.com
Guest

Posted: Fri Aug 01, 2008 3:38 pm Post subject: sight tube

Greg...per your request, a couple of pixs of my installation. Note that 

my intention w/ the tween-seats sight tube is to have a visual check 

while refueling, and to meet a regulatory requirement for a 2nd means 

of determining fuel on board; during flight, my expectation is to relay 

upon the Europa-mod fuel gauge and digital instrumentation. Note that 

the sight gauge in this location shows only fuel above top of tunnel.



Hope these help,



Fred



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gregoryf.flyboy(at)comcas
Guest

Posted: Fri Aug 01, 2008 5:51 pm Post subject: sight tube

Thanks for the pics. Nice installation Fred, and a great way for a refueling

check. The extra bidding is a good way to keep the surface flat. It looks

like the end fittings are plastic, as well. Any ideas as to the type of

sealant to use on the pvc-pvc fittings? I wonder if the standard pvc cement

will work, that is if it acts as a solvent and melts the plastic together,

it might be doing the same thing as the heat welds. What did you use?

Since yours were turned, I imagine some sort of sealer?



There is a big possibility I will install the site gauge in the front of the

seat back area, between the two seats. 

I have also heard of others placing it in the seat back area behind the

seats?? If anyone has a picture or link for that installation, let me know.

I would like to evaluate both, before committing.

 	  Quote: 	
		   Greg...per your request, a couple of pixs of my installation. 


	


Regards,



Greg F  A050

fklein(at)orcasonline.com
Guest

Posted: Fri Aug 01, 2008 7:42 pm Post subject: sight tube

On Friday, Aug 1, 2008, at 18:48 US/Pacific, Greg Fuchs wrote:



 	  Quote: 	
		   It looks like the end fittings are plastic, as well. Any ideas as to 

 the type of sealant to use on the pvc-pvc fittings?


	


Greg,



I tapped the tube ends to match up w/ a Nyloc nipple which threads into 

an aluminum 90 degree fitting at the top which is barbed on the other 

end to receive the vent tubing...the bottom of the pipe (not shown) is 

threaded to receive a Nyloc straight fitting which is barbed on the 

other end to receive the 5/16" teflon lined fuel injection hose which I 

used for the balance of my fuel system (aft of the firewall). All 

fittings from Acft Spruce; I used standard automotive thread sealant.



Fred

A194

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Roger.Mills(at)btinternet
Guest

Posted: Sat Aug 02, 2008 2:05 am Post subject: sight tube

I am concerned about the number of correspondents referring to PVC sight

tubes - PVC hardens and becomes brittle over time! In the UK there was an

incident or accident some time ago due to a massive fuel leak in flight

through a cracked PVC fuel tube - not something any of us would want to

repeat!



For this reason, the factory changed to polyurethane tubing - which,

although it discolours over time, is still readable after 5 years and can be

replaced at the same time as the rubber fuel pipes. 



For what it's worth, the original Europa routing isn't as bad as it's made

out to be - I find that on the ground it's perfectly accurate and repeatable

as long as you calibrate it properly. Although it's useless in level flight

at 120kts, by slowing down to 80kts and aligning (by sight) the passenger

front and rear door surrounds with the horizon, I get a reading

approximately the same as the static reading, as long as there's not too

much turbulence. (I wouldn't rely on it for critical remaining range

decisions - but you might have the same problem with a between the seats

routing due to parallax). 



Regards



Roger Mills

gregoryf.flyboy(at)comcas
Guest

Posted: Sat Aug 02, 2008 3:48 am Post subject: sight tube

 	  Quote: 	
		  ....I am concerned about the number of correspondents referring to PVC

sight tubes - PVC hardens and becomes brittle over time! ... 


	


Thanks for your thoughts, Roger. I too have heard that pvc tubing will not

last long. Is there any clear tubing that will last over 5 years anyway? 

However, the rigid pvc piping is supposed to last quite well. I say this

with not much experience however, and it is subject to change. Let me know

if you have direct experience with the piping. Is there anyone else holding

their breath, who could add to the discussion on pvc piping?

 	  Quote: 	
		  ...For what it's worth, the original Europa routing isn't as bad as it's

madeout to be - ...


	


 	  Quote: 	
		  Regards


	


 	  Quote: 	
		  Roger Mills


	


I think to original routing has its place -esp on the ground, but it does

not seem as practical to me as a sight gauge right next to the tank, which

won't suffer from attitude adjustments (I would need one of those, I expect,

after finding out the readings are not reliable in the air).



Thanks for your input. The goal is to make this thing as reliable as

possible, so any and all input is accepted and expected. Please re-add your

input on rigid pvc pipes, if you can.



Regards,



Greg

craigb(at)onthenet.com.au
Guest

Posted: Sat Aug 02, 2008 4:09 am Post subject: sight tube

anyone considered silicon fuel line. Its not quite clear but seems to last

well.



--

loboloda(at)execulink.com
Guest

Posted: Sat Aug 02, 2008 7:05 am Post subject: sight tube

I wonder if there are some extra volatiles crammed into Canadian auto  

gas.

The tubing supplied with the kit was rejected by my inspector as the  

first tank of gas

caused it to discolour and show signs of crazing.

The replacement polyurethane quickly discoloured.

Then I tried Bing tubing, stands up well, but soon went from a nice  

clear blue to a murky brown.



I've been using Shell or Petrocan premium, as I'm assured that they,  

along with Esso, do not yet

contain ethanol.



Dave

On 2-Aug-08, at 6:02 AM, Roger Mills wrote:



 	  Quote: 	
		   

 <Roger.Mills(at)btinternet.com>



 I am concerned about the number of correspondents referring to PVC  

 sight

 tubes - PVC hardens and becomes brittle over time! In the UK there  

 was an

 incident or accident some time ago due to a massive fuel leak in  

 flight

 through a cracked PVC fuel tube - not something any of us would  

 want to

 repeat!



 For this reason, the factory changed to polyurethane tubing - which,

 although it discolours over time, is still readable after 5 years  

 and can be

 replaced at the same time as the rubber fuel pipes.



 Regards



 Roger Mills

gregoryf.flyboy(at)comcas
Guest

Posted: Sun Aug 03, 2008 2:57 am Post subject: sight tube

Geez, with all the tubing that's changing to all different colors of the

rainbow from the 'who knows how it will effect it' gas, I am beginning to

think of using glass tubing for the sight gauge.  Maybe fully encasing it in

plastic tubing that would take over in case it ever broke from vibration.

Glass should guarantee no color shift, if it is reliable enough in this

environment.



--

gregoryf.flyboy(at)comcas
Guest

Posted: Sun Aug 03, 2008 3:15 am Post subject: sight tube

Craig,



Thanks,



In the technical bulletin below, it would seem that silicone might be even

worse than some of the others at standing up well to fuel. It is listed as

"Not recommended, severe effects imminent"

That is, If this bulletin is credible...

It lists Teflon, Nylon, and Viton to be the best materials.



http://www.sentranllc.com/pdfs/tb_chem.pdf



regards,



Greg Fuchs (A050)



___________________






 	  Quote: 	
		  anyone considered silicon fuel line. Its not quite clear but seems to last

well.

craigb(at)onthenet.com.au
Guest

Posted: Sun Aug 03, 2008 3:57 am Post subject: sight tube

Hmmm thats very interesting, we used to use it for racing when running high

octane 109+ gasoline type fuels and methanol

as it was about the only hose that wouldn't harden within a few days of

using it. It was about 15mm OD with about a 5mm wall  Perhaps it wasnt

strictly silicone line. I will see

if I can find out exactly what it was and let you know. Mind you I did have

one lot of line that i threw out after it started deforming

the day after a race meet, perhaps that was true silicone line



--

mikenjulie.parkin(at)btin
Guest

Posted: Sun Aug 03, 2008 7:00 am Post subject: sight tube

Why not 'bin' the sight tube altogether and fit an alternative gauging

system.  I have twin capacitance probes and they work brilliantly.

Regards,



Mike

--

gregoryf.flyboy(at)comcas
Guest

Posted: Sun Aug 03, 2008 10:24 am Post subject: sight tube

Mike, Of course, this is an option. I cut two holes in the top of the tank,

between the two headrests, and placed a mechanical float in the pilot hole,

and the other one is for upgradeability of the passenger side with the same,

or other fuel-related extras (second tank input, last-chance backup, or

whatever). The goal is to have a flow rate meter to tell the pilot how much

fuel is left, unless the tank begets a leak. Although unlikely to not have

other sensory inputs like smell, the first backup would be the mechanical

float. From reading other emails, the poly tank topside might ripple over

time. Because of its narrowness, it wouldn't take much movement (whether it

be rippling, or tank-top sender nut becoming loose, from the vibration) for

the throw of the mechanical wand to stick on the sidewall of the lower tank.

If one knew this was happening, it would be an easy matter to re-adjust the

wand in the tank. On the off chance that it snuck up on the pilot during

flight, it could make it seem that there is more fuel in the tank than

actual. Thus I like the simplicity of a third backup system being a sight

gauge. You can pretty much trust that you have what you see, if it is

installed properly. And if installed into the passenger side, it would allow

inspection of the reserve fuel, which is information that my one-float

system doesn't currently have, in its non-upgraded state. A good inspection

frequency would mitigate one caveat of the sight gauge -possible leakage due

to breakdown.



Of course, one could argue that the capacitance meter would be a good

replacement for the mechanical gauge, and it is. It would not be susceptible

to slight tank swelling due to fuel. Originally, that was my plan. But

capacitance gauges don't seem to be without their problems, either, such as

being sensitive to the different fuel additives being put into the tank. For

example, the alcohol is more conductive than the non alcoholic mogas, and

from what I have read, different fuels will affect the reading, like

switching between avgas and mogas. This will hinder the accuracy of the

gauge, and one could argue that the float could be at least as accurate, if

not more so -if the user is not married to one fuel type. Of course, a float

is also cost-effective on the pocketbook.



I don't mean to be anal-ytical about it all, but maybe it has happened.

Anyway, that is why I wanted the sight tube. Everything is subject to

change, of course. I might just throw in a second float for the 3rd

redundancy, and be done with it. The second float may only get in the way

slightly to the fuel related extras that will probably be using the second

hole, so I am still looking at the site glass/tube solution for now.



Hopefully, this has answered your question adequately 



Greg Fuchs (A050), over 800 hours into the beast


<mikenjulie.parkin(at)btinternet.com>



Why not 'bin' the sight tube altogether and fit an alternative gauging

system.  I have twin capacitance probes and they work brilliantly.

Regards,



Mike

gregoryf.flyboy(at)comcas
Guest

Posted: Sun Aug 03, 2008 10:30 am Post subject: sight tube

Yes, it would be interesting to know. It could be worth using if the useful

lifespan is high enough.  Let me know if you find out...

Greg



Do not archive



--

h&jeuropa

Joined: 07 Nov 2006
Posts: 645

Posted: Sun Aug 03, 2008 10:59 am Post subject: Re: sight tube

The factory supplied sight gauge tubing is polyurethane (see Chpt 30).  We noticed it was getting hard to read because of yellowing and also very hard and brittle after about 2 years exposure to auto gas.  Decided to replace it during our after ground loop rebuild.   



Went to the Tygon web site (www.tygon.com) to find alternatives.  F4040A is listed as fuel tubing.  However Europa supplied a length of that with our Long Range tank.  The F4040A was inside the main tank and exposed to gasoline.  After about 2 years it not only was virtually opague but it was hard and brittle.  Decided against F4040A.



Tygon Tech rep suggested Tygothane C210A or Tygon SE200.  Tygothane C210A is polyurethane without plasticizers.  It should hold up to gasoline well.  SE200 is PVC with a teflon liner.  A search of literature suggests teflon is one of the most gasoline resistant materials.  



We cut short sections of F4040A, SE200 and C210A filled them with auto gas and plugged both ends.  The gas eventually leaked out of all of them, but it was out of the F4040A in a day or two, C210A about a month and SE200 took 3 months.  We also put short pieces in a jar of auto gas.  F4040A has discolored and gotten much stiffer in 3 months.  C210A is discolored but not stiffer and SE200 the PVC has shrunk but the teflon liner has not changed.



So we are using SE200 for our sight gauge.  For the Long Range tank feed, we used C210A.  We also measure fuel quantity with a pressure sensor similar to Tony K's system feeding an input to our GRT EIS and the EIS calculates fuel usage from flow transducers.



Attached is a photo of the sight gauge up the back of the cockpit module.



Jim & Heather Butcher

N241BW

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grahamsingleton(at)btinte
Guest

Posted: Sun Aug 03, 2008 12:12 pm Post subject: sight tube

Greg

The neatest float gauge is the one Europa used to sell, It has a magnet 

attached to a cork and reed switches at 8 or 10 points to read level. 

Very reliable.

Best advantage of capacitance is if there's any water about in the tank 

they read full scale. As you say reading varies with fuel type.

Most elegant fuel gauge is Tony K's but you have to build it yourself.

Graham



This will hinder the accuracy of the

gauge, and one could argue that the float could be at least as accurate, if

not more so -if the user is not married to one fuel type. Of course, a float

is also cost-effective on the pocketbook.



I don't mean to be anal-ytical about it all, but maybe it has happened.

gregoryf.flyboy(at)comcas
Guest

Posted: Sun Aug 03, 2008 9:16 pm Post subject: sight tube

Hi Graham,



Yes, this magnet/reed switch idea does seem very reliable. Too bad its not

avail anymore. Hmmm.... I suppose someone can make a homegrown cork with a

magnet inside of it for the site glass/pipe, with some reed switches in the

back of it, out of the way behind the sight card.



I think the way the cap. meter reads the water at the bottom of the tank is

a great point, and a very good reason to have at least one in the system!



Was thinking of going with the Tony K idea at one point, but do not know

where to go to get the schematic/build description/programming data. Yes it

is quite elegant soln. Let me know if you have this info.



Regards,

Greg





--

gregoryf.flyboy(at)comcas
Guest

Posted: Sun Aug 03, 2008 9:33 pm Post subject: sight tube

Ahhhhhhhh..........Its like this information is just the prescription my

doctor ordered.  

Sounds like SE200 and C210A are the clear-cut winners, depending on the

application! Thanks for the update on the experiment.



I got the picture link, and will print it out. Thanks for that. It will come

in handy.



I am looking for a 'packet' of info, or anything I can get about a fuel

'head' pressure measuring system (the time needed to completely reinvent

this wheel would force me to a new path, I admire the time some have spent

to create this soln). Let me know if you have info on this.



Thanks again,



Greg

....snip..........

We cut short sections of F4040A, SE200 and C210A filled them with auto gas

and plugged both ends.  The gas eventually leaked out of all of them, but it

was out of the F4040A in a day or two, C210A about a month and SE200 took 3

months.  We also put short pieces in a jar of auto gas.  F4040A has

discolored and gotten much stiffer in 3 months.  C210A is discolored but not

stiffer and SE200 the PVC has shrunk but the teflon liner has not changed.



So we are using SE200 for our sight gauge.  For the Long Range tank feed, we

used C210A.  We also measure fuel quantity with a pressure sensor similar to

Tony K's system feeding an input to our GRT EIS and the EIS calculates fuel

usage from flow transducers.



Attached is a photo of the sight gauge up the back of the cockpit module.



Jim & Heather Butcher

N241BW

gregoryf.flyboy(at)comcas
Guest

Posted: Sun Aug 03, 2008 10:08 pm Post subject: sight tube

Jim,



BTW, I am surprised how much fuel escaped from the plugged tubes.

Could you describe how the ends were sealed? Do you think it is possible

that some fuel escaped around the seals?



Regards,

Greg F



....snip..........

We cut short sections of F4040A, SE200 and C210A filled them with auto gas

and plugged both ends.  The gas eventually leaked out of all of them, but it

was out of the F4040A in a day or two, C210A about a month and SE200 took 3

months.  We also put short pieces in a jar of auto gas.  F4040A has

discolored and gotten much stiffer in 3 months.  C210A is discolored but not

stiffer and SE200 the PVC has shrunk but the teflon liner has not changed.



So we are using SE200 for our sight gauge.  For the Long Range tank feed, we

used C210A.  We also measure fuel quantity with a pressure sensor similar to

Tony K's system feeding an input to our GRT EIS and the EIS calculates fuel

usage from flow transducers.



Attached is a photo of the sight gauge up the back of the cockpit module.



Jim & Heather Butcher

N241BW

rholder(at)avnet.co.uk
Guest

Posted: Sun Aug 03, 2008 11:55 pm Post subject: sight tube

Greg Fuchs wrote:



 	  Quote: 	
		   Yes, this magnet/reed switch idea does seem very

 reliable. Too bad its not avail anymore.


	


Shown on the Europa site as Mod 60.



Could be still available if it is shown 



 	  Quote: 	
		   Hmmm.... I suppose someone can make a homegrown cork

 with a magnet inside of it for the site glass/pipe,

 with some reed switches in the back of it, out of the

 way behind the sight card.


	


 	  Quote: 	
		   I think the way the cap. meter reads the water at the

 bottom of the tank is a great point, and a very good

 reason to have at least one in the system!


	


 	  Quote: 	
		   Was thinking of going with the Tony K idea at one

 point, but do not know where to go to get the

 schematic/build description/programming data. Yes it is

 quite elegant soln. Let me know if you have this info.


	


The capacitive meter reads differently for Mogas and Avgas 

I believe.



Richard

G-OWWW

High Cross

grahamsingleton(at)btinte
Guest

Posted: Mon Aug 04, 2008 12:37 am Post subject: sight tube

Greg

the reed switch device is available. 

<http://www.avnet.co.uk/lts/fuelgauge.php> Talk to Gerry Davis and tell 

him I told you. 

Tony K might sell you the chip and details for his gauge, ask him. 

<tonyk(at)kaon.co.nz>



The first stand alone gauge of this type was installed by Graham Clarke 

in the earl;y days. He used an old ASI to sense the head. Tricky to 

engineer but it did work. Our PFA weren't happy but Graham was a skilled 

innovator who worked for Marconi on radar and stuff.

Graham



Greg Fuchs wrote:

 	  Quote: 	
		   



 Hi Graham,



 Yes, this magnet/reed switch idea does seem very reliable. Too bad its not

 avail anymore. Hmmm.... I suppose someone can make a homegrown cork with a

 magnet inside of it for the site glass/pipe, with some reed switches in the

 back of it, out of the way behind the sight card.



 I think the way the cap. meter reads the water at the bottom of the tank is

 a great point, and a very good reason to have at least one in the system!



 Was thinking of going with the Tony K idea at one point, but do not know

 where to go to get the schematic/build description/programming data. Yes it

 is quite elegant soln. Let me know if you have this info.



 Regards,

 Greg

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