Vent line modifications

[Carl Froehlich]

I read about mud daubers and such clogging up vent lines - leading to fuel starvation and/or a collapsed tank.

I did two mods to address this:
- The last few inches of line is inserted into a 3/8? tube. The 3/8? tube provides the needed surface area to JB weld on a piece of aluminum screen. After the epoxy sets a few seconds on a stochbrite wheel to make it smooth. Done.
- I also wanted a backup in case of ice build up. I added a vacuum breaker valve. The valve is inside the airplane but as it only allows air in, any fuel burping out of the tanks still just goes out of the vents. The valve itself is very light and rated for fuel. I got it from McMaster Carr: https://www.mcmaster.com/plastic-check-valves
Part number 5492K51

The first photo is for the RV-10 or RV-14:

The next photo is the same idea but for an RV-8/8a:


Carl

[lr172]

I read a good tip a few years back. I installed a bent wire (like a paperclip) pushed into the vent fitting exiting the fuse. You use the bend to keep tension against the ID. 500 hours later, it still there. It makes the passage impossible for the daubers to get through.

I also added a check valve to vent cabin air into the vent line in case of ice over on the exterior fitting. A wise move for IFR flyers. Just be sure it has a low open pressure/vacuum rating.

Larry

[wirejock]

I'm using these. They have a screen built in. Gain a knot or two as well. Probably not but the look cool.
https://www.jdair.com/categories/Fuel-Vents/

[Carl Froehlich]

Originally Posted by wirejock

I'm using these. They have a screen built in. Gain a knot or two as well. Probably not but the look cool.
https://www.jdair.com/categories/Fuel-Vents/

Good option for the RV-10 or 14. Will not work on the RV-8/8A.

Carl

[rvdave]

I did two mods to address this:
- The last few inches of line is inserted into a 3/8? tube. The 3/8? tube provides the needed surface area to JB weld on a piece of aluminum screen. After the epoxy sets a few seconds on a stochbrite wheel to make it smooth. Done.
- I also wanted a backup in case of ice build up. I added a vacuum breaker valve. The valve is inside the airplane but as it only allows air in, any fuel burping out of the tanks still just goes out of the vents. The valve itself is very light and rated for fuel. I got it from McMaster Carr: https://www.mcmaster.com/plastic-check-valves
Part number 5492K51


I?ve thought about doing something like this for the 10. So do I have this right, you go from the tank to inside the plane(maybe under seats) to a tee with valve back out to the wing fairing?

[Carl Froehlich]

Originally Posted by rvdave

I did two mods to address this:
- The last few inches of line is inserted into a 3/8? tube. The 3/8? tube provides the needed surface area to JB weld on a piece of aluminum screen. After the epoxy sets a few seconds on a stochbrite wheel to make it smooth. Done.
- I also wanted a backup in case of ice build up. I added a vacuum breaker valve. The valve is inside the airplane but as it only allows air in, any fuel burping out of the tanks still just goes out of the vents. The valve itself is very light and rated for fuel. I got it from McMaster Carr: https://www.mcmaster.com/plastic-check-valves
Part number 5492K51


I?ve thought about doing something like this for the 10. So do I have this right, you go from the tank to inside the plane(maybe under seats) to a tee with valve back out to the wing fairing?

No. The vent line remains in the wing root. Just add a T like is shown in the photo.

Carl

[bobnoffs]

i used a screen out of a kitchen faucet but they are becoming hard to find.a ''head shop'' has perfect screens for about a dime a piece.

[Ralph Inkster]

Just curious. How fine a mesh/obstruction is needed to keep these pests out of the vent?
In past I've drilled small holes to criss cross at 90 degrees through the vent tube (or fitting) and inserted safety wire through them, held in place by shop peening the holes. Worked fine to this point for the pests we have around here, but am now wondering if this would be valid protection where mud doppers are a real problem.
My only experience with doppers was in a set of tanks that was brought to me to check out, I found the flop tube totally plugged by the little guys.

[Carl Froehlich]

I just used standard aluminum window screen material on the last three RVs. It keep the critters out.

Carl

[Ron RV8]

Originally Posted by wirejock View Post
I'm using these. They have a screen built in. Gain a knot or two as well. Probably not but the look cool.
https://www.jdair.com/categories/Fuel-Vents/

Originally Posted by Carl Froehlich

Good option for the RV-10 or 14. Will not work on the RV-8/8A.

Carl

I've got em on my -8 with a Rocket style tubing coil in the wing root. No issues...