AN fuel Vent fittings

aparchment · Post by **aparchment** » Thu Jan 10, 2008 11:27 pm

Guys:

Quick question. I need to order another AN833-4D 90 degree fuel vent fitting b/c I used the two I had on the left tank for a fuel return and fuel vent.

My question is should I order steel or aluminum? I am on the Spruce site now if anyone has an answer.

Thanks.

Antony

tshort · Post by **tshort** » Fri Jan 11, 2008 1:34 am

Pretty sure they are Al - the blue ones.

T.

captain_john · Post by **captain_john** » Fri Jan 11, 2008 8:50 am

Thomas is right. Aluminum, for many reasons.

They are color coded with blue to know they are the right ones.

Steel would be heavy, prone to corrosion and just wrong on an airplane.

CJ

weezbad · Post by **weezbad** » Fri Jan 11, 2008 10:37 am

they are alu, but remember to use steel firewall fwd. esp on the fuel line..i still have the alu for the oil cooler lines but those are large fittings.

captain_john · Post by **captain_john** » Fri Jan 11, 2008 10:46 am

Okay, I'll bite...

Why steel on fuel lines? Why steel on the FWF stuff?

CJ

smithhb · Post by **smithhb** » Fri Jan 11, 2008 12:38 pm

CJ,

There are those who believe you should use steel fittings so in the case of a fire, the fittings will not melt. I will tell you that this belief is NOT supported by folks at Vans, Don Rivera (AFP) or even AC-13.

If you look at any FWF setup you would have to replace all the AL fittings on fuel pumps, oil coolers, oil filters, carbs, etc. Incidentally, if you have a fire hot enough to melt the AL fittings, having steel fittings isn't gonna help you.

jim_geo · Post by **jim_geo** » Fri Jan 11, 2008 12:45 pm

This reminds me of boiling water in a paper cup.

captain_john · Post by **captain_john** » Fri Jan 11, 2008 1:38 pm

Ahhhh, I see.

Given that, I am still of the belief that AL is the way to go.

CJ

RV7Factory · Post by **RV7Factory** » Fri Jan 11, 2008 2:02 pm

smithhb wrote:If you look at any FWF setup you would have to replace all the AL fittings on fuel pumps, oil coolers, oil filters, carbs, etc. Incidentally, if you have a fire hot enough to melt the AL fittings, having steel fittings isn't gonna help you.

What do you think about using steel on just the fittings that penetrate the firewall? Do you think that would provide much value?

captain_john · Post by **captain_john** » Fri Jan 11, 2008 2:06 pm

Me? You askin' me?

I still say AL. The heater hole is GAPING compared to any AN bulkhead penetration.

CJ

RV7Factory · Post by **RV7Factory** » Fri Jan 11, 2008 3:21 pm

captain_john wrote:Me? You askin' me?

I still say AL. The heater hole is GAPING compared to any AN bulkhead penetration.

CJ

Asking anyone... this is a discussion group isn't it?!?!

You're right, but I was planning on using one of these stainless steel heater valves. I don't know, maybe I am fooling myself.

captain_john · Post by **captain_john** » Fri Jan 11, 2008 3:37 pm

Yup, I am planning on using one of those heater boxes too.

The heater box is sheet stainless. Not a chunk of ferrous steel like the AN fitting.

I like the idea of having the heater box constructed of similar material as the firewall.

CJ

smithhb · Post by **smithhb** » Fri Jan 11, 2008 3:45 pm

I just went through this exercise... I was discussing it with Don Rivera at Airflow Performance and he scoffed at the notion that using steel fittings for firewall penetrations would offer any additional protection.

He asked me if I was going to replace all the AL fittings on the engine and accessories too. He stated that a fire is a serious event and the only option was to land asap and extricate yourself (and passenger) from the aircraft.

This applies to the so-called stainless steel heater valve as well.

Don't shoot the messenger...

captain_john · Post by **captain_john** » Fri Jan 11, 2008 4:03 pm

I trust Don's advice.

That probably won't sway me from using the stainless heater box.

CJ

smithhb · Post by **smithhb** » Fri Jan 11, 2008 4:13 pm

I was looking at doing the same thing. Which heater box model are you planning to use? There is the traditional model and now I see a newer "square" box?

RV7Factory · Post by **RV7Factory** » Fri Jan 11, 2008 4:17 pm

I guess I agree with Don to a point, but I don't completely understand his rationale.

You can bet that if I were to have a fire I am coming down as fast as I possibly can, but how long that takes depends on your altitude. If having steel fittings on the FW prevents fire from entering the cabin for an extra 10 seconds, maybe this is the time when you are on short final to a landing, and those 10 seconds could make the difference between a successful touchdown and a tragedy.

I am certainly not challenging Don's experience or wisdom, just trying to understand the issue a bit better. Maybe his point is simply that the steel fitting won't buy you any time.

captain_john · Post by **captain_john** » Fri Jan 11, 2008 4:17 pm

1B, so I can control it from the inside of the cabin... I think.

CJ

weezbad · Post by **weezbad** » Fri Jan 11, 2008 7:08 pm

vans

they will tell you anything...the fuel pump comes with steel fittings, and the fitting you install with the pressure tap is also steel.

watch some shut downs and then tell me you feel totally comfortable with alu. sure they'll work for a long while but the certs ive looked at lately that are 30 y/o have steel.

its the countless cycles of tugging that concern me fwf not fire.
if it catches on fire im toast anyway

however its your plane put pvc on there if you wish, its experimental right?

so, where does the term "throwing gas on the fire" come from anyway?

captain_john · Post by **captain_john** » Fri Jan 11, 2008 7:16 pm

Willie, I am giving it due diligence!

I am going to pay special attention to the spammers at the FBO and see what they are doing. I am all about making a better product and if I see merit in steel, I will do it!

Fortunately, I have the luxury of time on my side.

CJ

RivetBangers.com

AN fuel Vent fittings

AN fuel Vent fittings

alu indeed

vans ?