Flop Tube Life Span

RV8Squaz · #1 10-12-2006, 05:17 PM

Hello Guys,
I know there is a recommendation for changing out the flop tube every five years. I finished building my wings more than five years ago and my airplane will be done soon. The flop tube has never seen an ounce of AVGAS. Do I still need to change it out? I thought about swapping it out for one made of Teflon hose but the only draw back I could see is that the Teflon hose would be quite a bit sttifer. Any ideas?

Jerry

Pmerems · #2 10-12-2006, 07:44 PM

I have a photo of an old flop tube removed from an RV-4 vs a new flop tube. The main issue I saw is that the flop tube is stiffer then the new one which means that when inverted the flop tube may not settle to the top (inverted is the bottom) of the tank.

http://www.experimentalaero.com/flop_tube_alert.htm

RV8Squaz · #3 10-15-2006, 07:58 PM

Paul,
Thanks for your reply. I wonder if the hose would have gotten that stiff without being submerged in fuel all those years. My tanks haven't seen a drop of fuel yet so the hose hasn't been subjected to the long term effects of AVGAS. I guess I'll be checking and/or replacing the hose when I accomplish Van's recent service bulletin on safetying the b-nuts.

Does anyone have any experience replacing the flop tube hose with a Teflon hose? I know the Teflon is stiffer, but is it so stiff to prevent the flop tube from operating properly?

Thanks for your help!
Jerry