Flare VS Compression fittings

[Bruce (VA)]

I learned a lesson today about the difference between the two fittings & I'm guessing one reason that Henry went to flare fittings on the N tractors instead of the compression fittings on the A Models.

My 29 Ford started having acceleration problems. Timing. points, etc were fine. I opened the fuel screen bolt to check the fuel screen going into the carb.

Check out the picture.

What happened was that the ferrule on the end of the fuel line moved allowing the line to extend into the carb too far; it compressed the fuel screen resulting in fuel starvation.

I cut a little kerf about 1/8" from the end of the line to keep the ferrule in place. And eye-balled it too!

75 Tips

 

[Fuddy Duddy]

That's what the folks from the gas company have always told me. Best the use the flare.

 

[L.B,]

Use a double flare.

 

[Fuddy Duddy]

Never heard of a Double Flare. What is that? Got a picture?

 

[L.B,]

You have a double flare where the fuel line goes into the elbow on your Ns carb and at the sed bowl .Do you have a flare kit?

 

[Fuddy Duddy]

I've got flare tools. I've flared copper lines going into the house. Since you bought it up I've looked at fuel lines and brake lines. When I flare a line the edges are sharp. Store bought lines are smooth as if the edges were turned in. But I can't tell that the edges were in fact turned in. Is that what you are talking about? Other than that I don't see any difference. I've never heard the term 'Double Flared'. I'm always willing to learn new things. But I'm having a hard time understanding what you are talking about. If you can explain more about 'Double Flare" I would appreciate it.

 

[Mickey Christian]

Not sure what it is called but double flare sounds good....
I have seen flares that are first "folded in" then put in the flaring tool clamp then the flare point is inserted into the opening and and in effect creating a double wall flare. Your flare nut should be on of course. Then when the nut is tightened down on the double wall it snugs up real good. I don't see this type anymore. It is more work and I think a proper single wall flare works as good, but may need more torque to seal.
Sound right to others?

 

[504]

look here
Untitled URL Link

 

[TheOldHokie]

(quoted from post at 17:18:53 01/05/14) Never heard of a Double Flare. What is that? Got a picture?

It is called a 45* inverted flare - SAE J512 - and is the standard flare for automotive hydraulic and brake lines. The mating connector has a matching seat machined into the inside. It is not the same as a JIC/AN flare or an SAE J512 single 45* flare. The three different types do not interchange and the fittings use different thread sizes and pitches to prevent mixing them.

TOH

 

[Bill M. From Illinois]

I don't believe compression fittings are supposed to be used for propane or gas fittings and do not think they are allowed for brake lines; at least in some areas. When I found out local mechanic used compression brake line fittings on replacing brake lines I went elsewhere.

 

[L. B,]

OH has it right in the drawing. As you can see the difference between the two flares. In your flair kit you should have the double flair tool. You know those little clamps that you squeeze open with pliers are the type of clamp to use on a double flair. A lot of people think those little clamps are useless but if used correctly on a flared end they do just fine. I still prefer the old band screw type. You can get an inexpensive flair kit at Home Depot they have the double flair if your kit does not have. Get your piece of copper or steel tubing and practice with.

 

[Fuddy Duddy]

Thanks, that clears it up. That's kind of what I thought it might be.
But didn't know for sure. First time I had heard that term. I've just
got a simple flare tool. It wouldn't do anything like a double. If I
need a new fuel line I'll just go the the parts store.

 

[ASEguy]

With the inverted double flare there is a 3 degree difference between the male end and the female end to facilitate sealing.

 

[ASEguy]

That's an inverted double flare which is common in automotive brake systems. Now, in automotive, we use ISO flares which are called bubble flares by some. The two are not interchangeable. Gerard

 

[TheOldHokie]

(quoted from post at 09:54:11 01/06/14) That's an inverted double flare which is common in automotive brake systems. Now, in automotive, we use ISO flares which are called bubble flares by some. The two are not interchangeable. Gerard

It's a bit more than just the form of the flare.

The SAE 512 45* flare (single and double) is specific to imperial (inch) tube sizes

The AN/JIC 37* single flare is also an imperial tube and fitting specification

The Europeans were using bubble flared ends with SAE J512 inverted flare fittings prior to the adoption of the DIN/ISO bubble flare specifciation. My 1962 TR4 is an example.

The DIN/ISO bubble flare is specific to metric tube and fittings.

Identifying flare fittings and ends

TOH

 

[GVSII]

(quoted from post at 18:51:54 01/05/14) Not sure what it is called but double flare sounds good....
I have seen flares that are first "folded in" then put in the flaring tool clamp then the flare point is inserted into the opening and and in effect creating a double wall flare. Your flare nut should be on of course. Then when the nut is tightened down on the double wall it snugs up real good. I don't see this type anymore. It is more work and I think a proper single wall flare works as good, but may need more torque to seal.
Sound right to others?

No,not right.Until a few years ago all U.S.built cars and light truck brake systems had double flares.Many foreign
makes use a bubble flare.The double flare tool is avaliable from any good tool or auto parts store.

 

[GVSII]

(quoted from post at 09:32:51 01/05/14) I learned a lesson today about the difference between the two fittings & I'm guessing one reason that Henry went to flare fittings on the N tractors instead of the compression fittings on the A Models.

My 29 Ford started having acceleration problems. Timing. points, etc were fine. I opened the fuel screen bolt to check the fuel screen going into the carb.

Check out the picture.

What happened was that the ferrule on the end of the fuel line moved allowing the line to extend into the carb too far; it compressed the fuel screen resulting in fuel starvation.

I cut a little kerf about 1/8" from the end of the line to keep the ferrule in place. And eye-balled it too!

75 Tips

If the ferrule is placed on a dead straight piece of line and the line is near perfectly round and the nut is torqued properly that fitting will hold for a LONG time. I've even used a compression fitting in brake system but not on a road vehicle.

 

[GVSII]

(quoted from post at 09:32:51 01/05/14) I learned a lesson today about the difference between the two fittings & I'm guessing one reason that Henry went to flare fittings on the N tractors instead of the compression fittings on the A Models.

My 29 Ford started having acceleration problems. Timing. points, etc were fine. I opened the fuel screen bolt to check the fuel screen going into the carb.

Check out the picture.

What happened was that the ferrule on the end of the fuel line moved allowing the line to extend into the carb too far; it compressed the fuel screen resulting in fuel starvation.

I cut a little kerf about 1/8" from the end of the line to keep the ferrule in place. And eye-balled it too!

75 Tips

If the ferrule is placed on a dead straight piece of line and the line is near perfectly round and the nut is torqued properly that fitting will hold for a LONG time. I've even used a compression fitting in brake system but not on a road vehicle.

 

[GVSII]

(quoted from post at 18:51:54 01/05/14) Not sure what it is called but double flare sounds good....
I have seen flares that are first "folded in" then put in the flaring tool clamp then the flare point is inserted into the opening and and in effect creating a double wall flare. Your flare nut should be on of course. Then when the nut is tightened down on the double wall it snugs up real good. I don't see this type anymore. It is more work and I think a proper single wall flare works as good, but may need more torque to seal.
Sound right to others?

No,not right.Until a few years ago all U.S.built cars and light truck brake systems had double flares.Many foreign
makes use a bubble flare.The double flare tool is avaliable from any good tool or auto parts store.