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mverick · 20th April 2007, 05:43

Quote: (Originally Posted by silent running)

From what I can tell, corrosion is the first symptom of wet O2 and it's more likely to screw up solenoid operation than rust. And doesn't rust need a higher amount of moisture to form than corrosion? In the cases I've heard of with Prism solenoids failing while in normal, consistant use they've clogged up and failed closed, including mine-corrosion. Considering the very tight restrictor that's in line btw the reg and solenoid in the Prism, I think that any particle that would be big enougth to actually block it open, could only come from inside the housing itself, from flaking rust, which takes a while to form.

And then you've got the gas pressure and the force of the spring, so it seems unlikely that it would fail open without lots of water ingress or neglect. Maybe I'm missing something?

Think flash rust in a tank. Happens very quick. I don't understand your corrosion happens before rust thing. Rust is the corrosion. If you get a lot of very small rust particles they can bind together and become a little hard rock. If there is moisture it's easy to do.

All Rebreather's have this. Not just a Prism by the way.

Solenoids fail open and closed. It's just how it works. Usually if it's corrosion they fail open. Not usually all the way open but they weep. Something mechanicly blocks it from closing If it's electronic where they loose the power they fail closed.

20th April 2007, 05:43	#18 (permalink)
mverick ScubaPimp Current Rebreather/s: Megalodon Other CCR Home Build Other Rebreather/s: Other CCR Home Build Join Date: Aug 2005 Posts: 543	Re: What is the lifespan of a solenoid? Quote: (Originally Posted by silent running) From what I can tell, corrosion is the first symptom of wet O2 and it's more likely to screw up solenoid operation than rust. And doesn't rust need a higher amount of moisture to form than corrosion? In the cases I've heard of with Prism solenoids failing while in normal, consistant use they've clogged up and failed closed, including mine-corrosion. Considering the very tight restrictor that's in line btw the reg and solenoid in the Prism, I think that any particle that would be big enougth to actually block it open, could only come from inside the housing itself, from flaking rust, which takes a while to form. And then you've got the gas pressure and the force of the spring, so it seems unlikely that it would fail open without lots of water ingress or neglect. Maybe I'm missing something? Think flash rust in a tank. Happens very quick. I don't understand your corrosion happens before rust thing. Rust is the corrosion. If you get a lot of very small rust particles they can bind together and become a little hard rock. If there is moisture it's easy to do. All Rebreather's have this. Not just a Prism by the way. Solenoids fail open and closed. It's just how it works. Usually if it's corrosion they fail open. Not usually all the way open but they weep. Something mechanicly blocks it from closing If it's electronic where they loose the power they fail closed.
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