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when fitting the fuel tank fittings??

miyu1975

Well Known Member
Am I suppose to use plumbers tape when screwing the "say" flop tube end to the blue fitting? If so, is it regular plumbers tape or special kind?..I am about to safety wire the fitting and wanted to make sure before proceeding..thx all
 
Am I suppose to use plumbers tape when screwing the "say" flop tube end to the blue fitting? If so, is it regular plumbers tape or special kind?..I am about to safety wire the fitting and wanted to make sure before proceeding..thx all
Teflon TAPE should NOT get any where near your airplane. Little pieces can break off and clog up your various filters. Fuel lube (EZ Turn) can be used on most all NPT fuel fittings. However, your flared fittings do not require any lube/sealants at all. Standard practice is to connect them dry. Teflon paste is also commonly used on NPT engine fuel fittings if fuel lube is not used there. Hope this helps.
 
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yes..thx. How about putting some proseal on the threads, making sure not to get any in the inner flop tube hole.?
 
Fuel Lube/EZ Turn

yes..thx. How about putting some proseal on the threads, making sure not to get any in the inner flop tube hole.?

Fuel Lube/EZ Turn is all you need. Pro Seal is like sending an 800lb Gorrilla to peel a bannana.
 
ok but...I have proseal..I don't have ez lube or the other stuff. The 800# Gorilla still can eat the banana right?
 
also..how tight are the tank fittings to be...how much torqued..didn't see it listed anywhere?
 
ok but...I have proseal..I don't have ez lube or the other stuff. The 800# Gorilla still can eat the banana right?
1. You're going to need it at some point in the build, so why not buy it now? It only costs a few bucks for a tube that will be more than enough for the entire build.

2. What exactly do you think you need the proseal or thread sealant for? The fuel tank fittings are all flared, correct? Flared fittings do not require any sealant or paste at all. They are generally assembled dry.

Regarding the torque--there are torque values in the Standard Aircraft Handbook. Alternatively, Van's also has a pdf on their website that suggests using the "tighten until finger tight and then one or two flats additional with a wrench" method. I'm paraphrasing the latter, so don't quote me, but it is a widely accepted practice that does not require getting a torque wrench on the fitting. Again, I'm pretty sure they have it on their website somewhere. Maybe someone else can provide the link to it. It's been posted here on VAF sometime in the past.
 
800lb gorrilla

will be needed if you ever have to seperate a fitting put together with Proseal..:)..Either that or a welding torch!

I just used teflon paste..never used fuel lube anywhere on the airplane..works great, just never needed it.

Frank
 
2. What exactly do you think you need the proseal or thread sealant for? The fuel tank fittings are all flared, correct? Flared fittings do not require any sealant or paste at all. They are generally assembled dry.

Yes...but I am speaking of the L shaped blue fitting that screws into the flop tube...see pic from brad site.
http://www.rv7factory.com/log/060803.html
 
Still a flared fitting

That's still a flared fitting and should be installed dry. I only used ez-turn/fuel lube on the NPT fittings -- flared fittings were installed and torqued dry.
 
I am really confused then on what is to be flared...I thought flareing was only done on the actual fuel tube or fuel vent tube... I am talking about screwing together to blue fittings together..the female end and the male end. How is that suppose to be flared?...:confused:

ps I order some ezturn..thx
 
Flared and fuel lube and pro-seal

Yea, the flare fitting doesn't need anything inside and gets tightened only a little past finger tight. I think it is about 24 in-lbs. A little fuel lube on the threads won't hurt. Put pro-seal on the OUTSIDE to keep it from leaking around it and the rib, and to help prevent coming off.

You'll need fuel lube to do leak test so order it now.

You might also go down to your local hardware store and look at all the types of fittings, flare, compression, NPT, etc and learn about them.

Finally, are you reading any construction logs as you go? There are several good ones that can give you extra insight. Check these out:

www.mykitlog.com/thelynns
www.mykitlog.com/sglynn
http://www.rv7factory.com/
http://www.rvplane.com/
 
I am really confused then on what is to be flared...I thought flareing was only done on the actual fuel tube or fuel vent tube... I am talking about screwing together to blue fittings together..the female end and the male end. How is that suppose to be flared?...:confused:

ps I order some ezturn..thx
Ryan-
I see why you are confused now. Definitely learning the terminology of the parts will help. Yes, you do flare the fuel tubing. That creates a "female" flare that then matches up to the "male" flare of the blue AN fittings. If the AN fitting end is cone shaped with no threads, that's a flared fitting. If it has threads, that's an NPT (pipe thread) fitting. You won't be using any NPT threaded AN fittings until you get to the brakes, so everything until then should be flared fittings. Consequently, you don't really need any fuel lube or teflon paste until you get to the brakes. As mentioned above, some people slather proseal on the OUTSIDE of the flared fittings inside the fuel tank just to make themselves feel better, but it's not necessary. As early as you are in the build, Van's still does a good job telling you what you need to do. If they don't mention fuel lube, paste, or proseal then you probably don't need it.
 
Fittings

I am really confused then on what is to be flared...I thought flareing was only done on the actual fuel tube or fuel vent tube... I am talking about screwing together to blue fittings together..the female end and the male end. How is that suppose to be flared?...:confused:

ps I order some ezturn..thx

Ryan:

If you are screwing two blue aluminum fittings together, they're probably NPT or National Pipe Thread fittings. The female is tapered with the widest part at the opening. The male is tapered with it's narrowest part at the end. When they are screwed together, they tighten and form a fluid tight joint theoreticaly. Fuel lube/tight seal aids in making that joint leak proof as these are impervious to gasoline. Other examples are the fuel drains on the underside of the fuel tank and the fitting that connects your brake lines to the brake calipers. Other examples are on the accessory case of the engine where the oil cooler lines and crancase breather connect.

These fittings generally have both the NPT thread on one end and the AN Flare on the other.

A flare fitting is generally on the end of an aluminum tube with a nut that fits onto the untapered thread on the male end of an AN fitting. That end has a 37.5 degree taper at the end of the threads that mates to the flared end of the tubing. the nut on the end of the tubing tightens onto the AN fitting. This is the one that doesn't require Fuel Lube/Tight Seal. These are torqued according to tables that I don't have handy, but are generally 1 to 1 1/2 flats past hand tight. (Look it up, don't take my word for it)!
 
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A flare fitting is generally on the end of an aluminum tube with a nut that fits onto the untapered thread on the male end of an AN fitting. That end has a 45 degree taper at the end of the threads that mates to the flared end of the tubing. the nut on the end of the tubing tightens onto the AN fitting. This is the one that doesn't require Fuel Lube/Tight Seal. These are torqued according to tables that I don't have handy, but are generally 1 to 1 1/2 flats past hand tight. (Look it up, don't take my word for it)!
That would be a 37.5 degree taper for the flare on aircraft fittings. The auto industry uses 45 degrees. Please be careful and don't use a 45 degree flaring tool on aircraft fittings.
 
Fittings

That would be a 37.5 degree taper for the flare on aircraft fittings. The auto industry uses 45 degrees. Please be careful and don't use a 45 degree flaring tool on aircraft fittings.

Mel:

Boy did I screw up. Sorry slip of the tongue. I really meant 37.5 deg. instead of 45 deg. I corrected in my original post. Should try typing slower and proof reading!!!!!! Sorry:eek:
 
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thx for all the info/help...I think I got it now. I went ahead and order ez turn lube from spruce. 1/2 done with first tank sealing now..shewwww
 
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