Interesting spit-valve/condensation question

[Beervangelist]

Ok, it might not be that interesting...

This last weekend, playing a fair amount of sets both indoor and outdoor on my sousaphone. I noticed that i was collecting some water, that wouldn't blow out the spit-valve. A couple weeks ago, this happened and I isolated the water to the third valve, pulled it out- inverted the horn, and voila. This weekend, I needed to take the bell off and rotate the whole horn until the culprit poured out.

Any ideas on why this is happening and not settling in a way I can get it out the valve intended to empty?

It didn't pose a huge problem this time, but running into that in the middle of a set where you can't invert your horn would be a bit of an inconvenience. So, if it's some sort of symptom I need to pay attention to, I should get to work. On the other hand, my temperature swings were pretty wide this weekend playing in 35/40 degree tent, then moving indoors, then traveling and back indoors. Perhaps I had more condensation than normal?

Insight appreciated...

[imperialbari]

The higher the intensity of your playing (loudness and lack of breaks/rests), the later in the bugle the water will condense, because the intensity of your airstream warms a longer portion of the bugle (including the valve tubing).

If one valve is used significantly less than the others, its tubing will do a lot of condensation WHEN it is used.

The best profylaxe is about circling the sousaphone body before each set to empty all the funny places.

Klaus

[Donn]

Some tubas' valve sections are like that, they collect water where it's awkward to drain it. I don't have water keys on any of the valves on my Holton, but the tuba that really gives me trouble is a King, first valve tubing has a low spot next to the valve that's hard to empty. It's unclear from your description what exactly is going on, but if it's pooling up in the 3rd valve loop, and that's awkward to pull, then maybe install a water key.

[Ace]

I had a Holton 190 double French horn F/Bb wherein condensation pooled in the third valve slide on the Bb side. I had a spit valve installed on that slide. Solved the problem. Dick Akright did the work and commented that pooling in that location was a frequent problem on horns.

Ace

[MaryAnn]

Klaus has the science exactly right. The cool tubing will condense the most water. So....you could somehow make all the tubing warm, but....eh, that is asking a bit much.
Me....I put a Joykey on that is laughed at here but which is working extremely well for me. Same size as an amado key. I have to empty water before the tuba is warmed up, and never again after that unless it cools off again.

[TheGoyWonder]

The superior circular design of a sousaphone makes it easy to spin. Spin forward 1x should be fine on any BBb. Eb's can have a switchback and be trickier.

[imperialbari]

The problem with the 3rd valve of sousaphones with the American valve wrap is the extra top loop, where moisture blown into the activated 3rd valve will end up in the lower crook between the 2 top crooks. A full circle spin shouldn’t be necessary to get the water down to the pullable 3rd slide.

Rotary valves are designed so that the rotor does not touch the wall of the valve casing. Most horn players hold their horns so that the 3rd rotor is the lowest. The Bb side slides lie below the F-side slides. That is why the water blown in to the valve block ends up in the 3rd slide of the Bb side. The water simply runs downwards.

Klaus

[Three Valves]

Maybe something to do with pressure differentials, null hypotheses, and arnold jacobs?

As a moderator, I would hope you could limit your responses to those that are actually helpful.
Leave snide comments to the unwashed masses.

You know, I come here to TubeNet to get away from fluid dynamics...

[Beervangelist]

Thanks all for the help.

I think long sets in cold weather moved the condensation point, which makes some sense.

Appreciate the insight -