Tank return line size?

[DWC7A]

About to close one of my tanks. I am considering a fuel-injected engine that would require a return line. What size should it be? 3/8" or 1/4" fitting? Any ideas would help. Thanks

DWC7A
working on tanks, QB fuse waiting on me

 

[bullojm1]

I did 3/8" in mine just to be future proof. If I did it again, I would of penetrated the tank where I did (see builders log http://rvplane.com/?categoryid=3&dayid=214 for location and parts). The one thing I would do is snake the return line as high as possible on the second and third rib. You are supposed to put the return line as high as possible to keep the backpressure to a minimum - no big deal if you don't because you can use a check valve, from what I have read. If you are using flop tubes and/or capacitive senders, make sure you account for possible interference.

Here is a pic of the tube penetration and into the second inboard rib.

Here is a pic of where it ends, on the third bay inboard:

Use the search feature of these forums to find a bunch of other threads on this topic.

 

[DWC7A]

Thanks Mike. I was thinking along the same line. I am going to put 3/8" and can reduce it down or block it off if plans change. I am also using capacitive plates. 3/8" would have less restriction anyway. Your Pro-Seal is neater than mine. Is your location OK as far as wing atachment? Tanks alot. (ha-ha)

Dennis Conner
DWC7A
Tanks QB fuse

 

[bullojm1]

Is your location OK as far as wing atachment?

A lot of other builders put the elbow oriented as I did. I *think* it won't cause any issues, but I am a year or more away from joining the wings to the fuse. Hopefully someone else can chime in. As far as the proseal application, I went way anal on it. I used a q-tip soaked in MEK to clean up each proseal mess. It actually wasn't that much effort and cleaned up way fast. Now I just have 1000 q-tips stuck to the sides of my trashcan in the shop!

 

[N184JG]

I talked to ECI and they said 1/4" is all that is needed.