I recently made the switch from a wedge tank to a 4oz Dubro clunk tank to feed my OS FP 35. I have a pressure line from the muffler to the uniflow vent. It runs very well and I like it much better. But after I fill the tank, while I'm waiting my turn to fly, I don't want the fuel dribbling through the pressure line, so I've been clamping it, but wondered about putting in a check valve. I've seen people do this with backplate pressure lines on Tee Dees, but I wondered if the one way valve could cause too much pressure to build up in the tank. Of course, the volume of fuel is dropping as the engine runs. Does that completely offset the buildup? Will the valve affect my run, or should I see any difference with or without the valve?

Thanks.
Rusty

......I think a check valve would present all sorts of problems, starting with the fact that you'd need one with very little back pressure that could seal well, all while being very light and being able to withstand vibration and rough handling.

Yep, that's kinda what I thought. I don't want to change the configuration since it works so well, from steady run to cutoff. I'll just get an inline clip for it so I don't have to mess with the hemostats. I'll swipe one from dialysis in the morning.
Thanks, Tim.

Rusty

Yep, that's kinda what I thought. I don't want to change the configuration since it works so well, from steady run to cutoff. I'll just get an inline clip for it so I don't have to mess with the hemostats. I'll swipe one from dialysis in the morning.
Thanks, Tim.

Rusty

  Howard's idea of a loop is more-or-less what I have. I would never use hemostats on silicone fuel line. There's too much potential to nick the line. Although my World Champion buddy does it all the time.

   Brett

 How about just waiting until you're ready to fly to fuel up? Just a thought...

I think you're being over-anxious, at least if you do the "loop up and over" thing on the muffler pressure line.  When the guy in front of you starts flipping his prop you have time to recruit a pit crew (if necessary), fill the tank, walk your lines out for twist and dirt, and get a little bit bored before he lands.  Your worst concern is that your pit crew may forget and wander off.

I think you're being over-anxious, at least if you do the "loop up and over" thing on the muffler pressure line.  When the guy in front of you starts flipping his prop you have time to recruit a pit crew (if necessary), fill the tank, walk your lines out for twist and dirt, and get a little bit bored before he lands.  Your worst concern is that your pit crew may forget and wander off.

Over anxious, probably so, since I've only been there once. I'll get the hang of it. I haven't gotten to the part about being bored yet.

They may be out of business.  My local hobby shop told me that the filters were no longer available.

Someone mentioned that in another thread. I have a couple of Fourmost check valves, and use their filters on my smallest 1/2A bladders like the Li'l Satan where there's barely enough room to fit it all.

Rusty