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silent running · 20th April 2007, 02:46

Quote: (Originally Posted by jradomski)

The PRISM solenoid is basically a copy of a snaptite solenoid.. The failure we are talking about can EASILY fail open.. this is not due to electronics failure but rather a mechanical failure..

ALL the Rebreather solenoids I am aware of pull open against the source pressure, so the higher the pressure (or no current flow) the solenoid is forced shut..

Hi Joe, the Prism solenoid is actually the Snaptite solenoid. SMI bought the tooling from Snaptite when they discontinued the model so they could manufacture it themselves.

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?

20th April 2007, 02:46	#17 (permalink)
silent running Mature mouth breather Current Rebreather/s: Prism Topaz Other Rebreather/s: Join Date: Jun 2005 Location: U.S.A. Brooklyn, New York Posts: 1,836	Re: What is the lifespan of a solenoid? Quote: (Originally Posted by jradomski) The PRISM solenoid is basically a copy of a snaptite solenoid.. The failure we are talking about can EASILY fail open.. this is not due to electronics failure but rather a mechanical failure.. ALL the Rebreather solenoids I am aware of pull open against the source pressure, so the higher the pressure (or no current flow) the solenoid is forced shut.. Hi Joe, the Prism solenoid is actually the Snaptite solenoid. SMI bought the tooling from Snaptite when they discontinued the model so they could manufacture it themselves. 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?
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