Brass fuel line fittings?

[TXFlyGuy]

Is it ever acceptable to use solid brass fittings (hose barbs / T-fittings) in a fuel line? We are having a debate...one friend and RV-8 builder says NO! And another builder claims it is very safe.

Who is correct?

[Mike H]

Lots of vintage aircraft use brass fittings in the fuel system. What specific application in the fuel system are you referring to?

[TXFlyGuy]

Originally Posted by Mike H

Lots of vintage aircraft use brass fittings in the fuel system. What specific application in the fuel system are you referring to?

Coming out of the fuel tank, between the fuel pre-filter and the fuel pumps. A brass T coming off the filter, then going to the pumps via a hose barb. All safety wired.

[rv7charlie]

I suspect that the bigger ones are what caused their bad reputation; the wall thickness vs total size tends to suffer as they get larger. Brass wouldn't scare me if I could make sure it wasn't 'stressed' by static loads, and vibration wasn't an issue. Using one on an engine does get a little more dicey. A fried just lost a Cessna 195 to a brass 'L' in the oil system (a certified part, BTW).

If you're really concerned, you can probably get the same part as an A/N fitting in your choice of materials, or at least a stainless plumbing part.

Charlie

[TXFlyGuy]

Originally Posted by rv7charlie

I suspect that the bigger ones are what caused their bad reputation; the wall thickness vs total size tends to suffer as they get larger. Brass wouldn't scare me if I could make sure it wasn't 'stressed' by static loads, and vibration wasn't an issue. Using one on an engine does get a little more dicey. A fried just lost a Cessna 195 to a brass 'L' in the oil system (a certified part, BTW).

If you're really concerned, you can probably get the same part as an A/N fitting in your choice of materials, or at least a stainless plumbing part.

Charlie

As this is well back of the firewall (at the fuel tank), I do not think it will be an issue. The fittings are 3/8".

[Mike H]

Originally Posted by TXFlyGuy

Coming out of the fuel tank, between the fuel pre-filter and the fuel pumps. A brass T coming off the filter, then going to the pumps via a hose barb. All safety wired.

It's not what I prefer to use but I does not sound like a safety of flight issue either. Lots of vintage and very light aircraft use hoses with barbed fittings and clamps. I prefer to use flared fittings.

[TS Flightlines]

Alot of planes had brass, but they also used rubber push on hose too. Several LSA aircraft still use it. Costs less than AN hardware, and is easier to install.
But---its still brass.
Tom

[TXFlyGuy]

Is there something inherently dangerous about brass mixing with fuel?

[krw5927]

Originally Posted by TXFlyGuy

Coming out of the fuel tank, between the fuel pre-filter and the fuel pumps. A brass T coming off the filter, then going to the pumps via a hose barb. All safety wired.

I've always heard to stay far, far away from hose barbs, clamps, and the like in aircraft fuel systems. Also that fuel system issues are a primary, if not leading, cause of "eventful" first flights. Please be careful here. Sticking to the most common fuel system materials and the plans is one way to ensure reliability.

(Note that I'm not saying don't do this, you'll fall out of the sky, or anything like that.)

[airguy]

Brass and fuel? No, no problem there - just that the brass is not as strong as a steel or aluminum AN fitting under vibration.