Sign in to follow this  
Followers 0

Intalling wing tank vent line (at the tank)

9 posts in this topic

Posted

Getting ready to intall the wing tank vent line (the connection at the gas tank). However, I only have an inch and a half (between the tank and outer rib) in which to make the radius To include the fitting). It appears to be 1/4 NPT hole into the tank, right at the top, with no room to swing an elbow (only a straight fitting). How do you guys handle this? Probably some sort of fitting and female/female elbow?

Share this post


Link to post
Share on other sites

Posted (edited)

I would have to look in Spruce for the numbers - but they make a straight fitting with NPT on one end and a male flare on the other - then use a female flare elbow with a hose fitting on the end.  Still a tight fit.

More than one way to do it tho - You can use a very short NPT / Hose (Weatherhead) straight fitting or cut the hose end off short of a regular fitting.  Sometimes, just a small notch in the rib will get your tube clear.

Maybe a 45 degree hose fitting might clear.

EDMO

Don't forget to put a plug in your lower sight gage fitting with a 1/16 hole in it - makes readings steadier.

And, you can get the little red pellets from Bear Perkins site - but you may have to increase diameter of sight tube.

Edited by Ed In Missouri
1 person likes this

Share this post


Link to post
Share on other sites

Posted

I'm assuming your describing the same issue we had with ours. what we found to be a common fix was just to take a bit of material out of the rib web in that area. I used a sanding drum on a dremel and just rounded it off quite a bit until I could get not only just the straight fitting but also a socket over it. that way if i ever need to take it out later it is easy to get at. The structural integrity of the wing is not dependent on this sole rib so don't worry too much about removing the material here. 

Share this post


Link to post
Share on other sites

Posted (edited)

My wing tanks don't have the extra tapped hole for the vent line - I will put a T at the top of my sight gage for the vent line. 

Well, "Dum-Dum" only looked at the left wing - should have looked at the right wing - vent hole is probably there - you only need one vent line from header tank...Two vent lines connected would probably cause the wing tanks to try to equalize in a bank, even if you have shut one off - but I would rather fly with both on, and let them equalize.

EDMO

I don't know why the Avid Drivers couldn't drill a 1/8" hole in the side of the tank at the highest point, sand a little around it, and epoxy a fitting there for a vent line?  Or, drill larger and stick the fitting into the tank and epoxy it - A double-ended hose fitting should work that way - Looks like it would work better than some ideas I have seen....A clear vent line should also show the height of the gas in the tank, as a sight gage....I think.

Edited by Ed In Missouri

Share this post


Link to post
Share on other sites

Posted

My hearer tank just vents out the 2 incoming lines.  As long as one tank has more fuel in it than the other at the initial fill up it will vent to the empty tank.  Once the header tank is full your good to put fuel in the other tank.  I have a clear section of hose between the tank and the aluminum line running to the header tank so you can see if there is any air in the system.  No need for separate vent lines.

 

If you are convinced you need a separate vent line, the easiest I have seen is a valve on the top of the header tank going to a clear hose that is routed under the plane.  You can open the valve and purge the system and catch it in a jar under the plane, or open it in flight and it will just dump over board but you can see the gas in the system and know there is no air bubbles going through.

Share this post


Link to post
Share on other sites

Posted (edited)

I have lost the Permatex 9AR number on the stuff that Kitfox sells for fuel fitting sealer - is there another nuber on the tube, and not the Kitfox number - Anyone have it?  It is on the package or tube that autoparts stores sell.  They have about 50 different sealents, but I want the right one for threaded fuel fittings.   I think I am out of Loctite 545, or just cant find it.

Where can you buy aluminum, not brass, NPT plugs cheaper? 

  I found some at Speedway racing, blue anodized, but OMG - at $3.50 each for 1/8 NPT, I will have to use my old brass ones from ACE hardware!

EDMO

Edited by Ed In Missouri

Share this post


Link to post
Share on other sites

Posted (edited)

I corrected the above post when I had asked for an RTV number and didn't get an answer.

Permatex has some 5-diget numbers on the stuff at autoparts stores.   Kitfox lists it as 9AR, supposed to be fuel resistant.

EdMO

I found a Permatex 54540 pneumatic and hydraulic sealant that seems to be just like my Loctite 545 - it comes in a small blue bottle - you can remove fittings without heat - Guess I will give it a try on my fuel fittings.

There is also a 59214 High Temperature sealant which is fuel resistant.

Still wish I could get the Permatex number for the "9AR" that Kitfox sells.

Edited by Ed In Missouri

Share this post


Link to post
Share on other sites

Posted

EDMO,

Found this information on a thread on the other site - http://www.teamkitfox.com/Forums/showthread.php?p=9022. Based on this info, it looks like the new part number is 80938. Is this what you're looking for? If so, I found it at a few places including this site: http://www.qualitydist.net/per-80938.html

 

Permatex® Tack & Seal™ Gasket Sealant
Non-hardening for easy disassembly. Keeps large gaskets in place during positioning and assembly. “Clean hands†formula won’t stain. Temperature range -65°F to 400°F (-54°C to 204°C); resists engine fluids including diesel fuels and synthetic oils.
Suggested Applications: Seals air conditioning, fuel fittings, radiator hoses, PVC fittings and cork, paper, cardboard, felt and metal gaskets
Item # 80938, Container Size 1.25oz. tube, Pack 12, Old P/N 9AR

Share this post


Link to post
Share on other sites

Posted (edited)

Thanks Rob,

     I will look for it at the autoparts store - Just hated to pay $$$ shipping for one little tube from Kitfox.

     I have tried several times to get fuel fitting/fg tank thread sealer info on the Permatex site, and not much luck so far.   LOOKS LIKE - Permatex 80017, Aviation Form-a-Gasket #3D might be a good choice for fuel-proof sealing.... and you can buy 16 oz for about $10, compared to the 1.25 oz tube that Kitfox sells.

     I will reserve the Permatex 54540 for a mild threadlocker/sealer for bolts - Same for Loctite 545.

EDMO

     I know that Leni's way of venting will work - I just like the Kitfox way better, because it is a passive automatic system - You don't have to do anything if you have it - and, you get a free sight gage too, so you know there is gas in the header tank!

Edited by Ed In Missouri

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0