Re: 912ULS manifold pressure
cposer,
Similar to a water trap on a natural gas line, or a static line on an aircraft, I suppose it's just a capped-off short section of line, or small container that is connected with a tee fitting to the MP line and oriented to go down from it. Any liquid that may be in the line is then "trapped" in that short line or container before it gets to the sensor. There will also be a plug, cap or valve at the bottom of the trap to empty it if necessary. There may be something made commercially if you Google it. I know that there is a plastic one (used on some Cessnas?) for the static system, but I haven't really heard of one being used on a manifold pressure sensing system. I'm sure someone else is better informed than I about this and will chime in.
Re: 912ULS manifold pressure
I saw the Rotax recommendation so I installed a trap in my manifold pressure sensor line at the lowest point. I found a small brass tee fitting with 1/4" hose barbs inline and a female 1/8 npt on the tee. I use a 1/8 npt male plug that can easily be removed to drain it. I do it at the yearly annual, but have never had more than 1 drop come out, sometimes none; been in there 7 years now. Probably one of those nice to do things, but not really necessary.
Re: 912ULS manifold pressure
Think I found the brass tee at Home Depot but not sure.
Re: 912ULS manifold pressure
Thanks, I ordered one from amazon. Are you running a constant speed prop?
Re: 912ULS manifold pressure
No, just a ground adjustable fixed. I don't know why I measure MP; its not very useful with a fixed prop.
2 Attachment(s)
Re: 912ULS manifold pressure
For anyone interested this is what I ended up with for a manifold pressure line water trap. It is an 1/8"x1/8"x1/8"male NPT tee fitting. I then machined a cap with a little reservoir on it.Attachment 24772Attachment 24773