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View Full Version : AN fitting to line size?



gmjj13
05-20-2008, 09:50 AM
i tried to do a search, and came up empty. i am trying to figure out what size AN fitting works with what size fuel line. is there a chart somewhere that lists the sizes? is -6an equal to 3/8 or 5/16 or ???

main reason i ask is that my fuel tank has 3/8 line with 1/4 return. the fuel pump i am wanting to use has -10an fittings. i'm new to trying to plumb my own fuel system, and just want to find out what i need to get it together. these may be stupid questions, but there ones that i don't know the answers to. thanks for the help in advance.

eville
05-20-2008, 10:04 AM
to find the tube size equivalent take the dash number and divide by 16.

so -6 divided by 16 = 3/8"
-8 = 1/2"
-10 = 5/8"
-5 = 5/16"

and so on

gmjj13
05-20-2008, 10:07 AM
thank you much sir...

Adam's 55 Chevy
05-22-2008, 08:25 PM
Open up your return to at least the same size as the feed line. At idle you will need to return 90% of the fuel to the tank with a return reg.

twov8sandat4
05-28-2008, 06:08 AM
to find the tube size equivalent take the dash number and divide by 16.

so -6 divided by 16 = 3/8"
-8 = 1/2"
-10 = 5/8"
-5 = 5/16"

and so on

Unfortunately it does not work that way all the time. I have used at least two - three different brands of AN fittings and hoses, and found out that the advertised size and actual size are not the same. It seems the actual size is 1/16" smaller than posted, so a -6 is actually 5/16" id, -8 is 7/16" id, and so on... I have only gone up to -10, so I have no experience with the larger sizes.

FWIW

gmjj13
05-28-2008, 07:16 AM
thanks for the info. i should be getting ready to plumb my fuel system next week. i have my fuel pump/reg/filters, just need to get my fittings for my hose. i decided to have a sump put in my tank as well. i guess i'll just have to make sure and do some good measuring...

CarlC
05-28-2008, 10:59 AM
Tubing is rated by the O.D., so when wall thickness is accounted for the actual tubing bore is smaller.

Hose on the other hand is rated by the bore size, but the fittings are often quite restrictive. For example, a -6 hose end could neck down to almost 1/4".

A hard tube will almost always have a better flow rating than a hose of eqivalent size.

tumper93
05-28-2008, 11:23 AM
I read somewhere that the AN lines were sized as the number was diameter in 1/16 increments ie. -3=3/16, -6=6/16 (3/8) so on and so forth! But I can see what Carl is saying as being the truth also because it does seem to vary with manufacturer. I wonder if this is the same for the teflon stuff since it is a covered line as opposed to a rubber/metal hose?

CarlC
05-28-2008, 05:46 PM
All flexible hose is rated by the bore size. All hard tubing is rated by the O.D.

Teflon hose ends tend to be less restricive than standard AN hose ends.