Auto Closure Device

[kelemvor]

Interesting take on dust caps. I used to think they were for the purpose of sealing the regulator. Then the guy at the LDS "explained" that they were not. After seeing the protective cap thing in this thread I reconsidered. However all the online sites seem to only be selling "dust caps" as well.

Maybe your yoke reg has something different than what I've seen. I guess that's a possibility. A little piece of soft conical rubber that gets sandwiched in by yoke is what I've got and that is not reliable.


Regulator dust cap on google turns up the thing you put on the fist stage of a scuba regulator.

Regulator protective cap on google turns up a large metal device that goes on top of a tank of pressurized gas. Something that would be likely used in welding while a regulator is affixed to a tank of gas.

 

[Nemrod]

Interesting take on dust caps. I used to think they were for the purpose of sealing the regulator. Then the guy at the LDS "explained" that they were not. After seeing the protective cap thing in this thread I reconsidered. However all the online sites seem to only be selling "dust caps" as well.

Maybe your yoke reg has something different than what I've seen. I guess that's a possibility. A little piece of soft conical rubber that gets sandwiched in by yoke is what I've got and that is not reliable.


Regulator dust cap on google turns up the thing you put on the fist stage of a scuba regulator.

Regulator protective cap on google turns up a large metal device that goes on top of a tank of pressurized gas. Something that would be likely used in welding while a regulator is affixed to a tank of gas.

I do not know what you guys are talking about, the caps on my regulators are either metal or hard nylon and have an O-ring seal. The cap on my wife's Legend is a rubber thing, which serves no purpose other than to protect the sealing surface of the ACD first stage.

Why would you be concerned about dust getting in there, what kind of dust? People repeat what they hear without ever questioning it, so does Google. I do not care what you guys call those caps, mine will seal I am quite sure to some significant depth quite a bit deeper than any rinse tank and it is not anecdotal as I have been servicing my own equipment for over 40 years and I have yet to find dust in my first stage much less water unless I dropped the regulator into water without the cap in place or otherwise flooded it doing something silly like changing regs and tanks underwater etc.

N

 

[redacted]

I have Atomics and they warn against soaking unpressurized, so I don't do it.

Is that because of the cap or the seat saver feature. A 2nd with a seat saver feature may requires some special attention.

I prefer the older style Scubapro protective caps (that is the name on the schematics) that are solid rubber. The newer 2-piece ones seem to work OK on yoke 1sts but I don't use them on din. I have cracked the aftermarket plastic caps with o-rings seals so I am careful if I run into one of those.

I can't find a picture right now but the scubapro part # is 10-101-110 from a 1997 schematic.

 

[Nemrod]

One thing, regarding our arguments over dust caps vs regulator caps, do not use an O ring sealed regulator cap on an AL ACD regulator. Use the supplied rubber cover and only tighten the yoke enough to secure the rubber cover but not enough to open the ACD valve. The reason is that it, an O ring sealed cap, will offset the ACD valve just as it would if installed on a tank. Of course, it would still not leak because it has the O ring sealed cap in place but why pay for a feature, ACD, and then not use it. And the ACD works fine and it is not a failure point, not the AL version anyway. It is fool proof and reliable and it is a good feature for traveling divers.

N

 

[flots am]

Is that because of the cap or the seat saver feature. A 2nd with a seat saver feature may requires some special attention.

I believe it's the seat saver.

The second stage is open when not pressurized.

 

[reefrat]

One thing, regarding our arguments over dust caps vs regulator caps, do not use an O ring sealed regulator cap on an AL ACD regulator. Use the supplied rubber cover and only tighten the yoke enough to secure the rubber cover but not enough to open the ACD valve. The reason is that it, an O ring sealed cap, will offset the ACD valve just as it would if installed on a tank. Of course, it would still not leak because it has the O ring sealed cap in place but why pay for a feature, ACD, and then not use it. And the ACD works fine and it is not a failure point, not the AL version anyway. It is fool proof and reliable and it is a good feature for traveling divers.

N

The latest version of the legend has a cap that fits completely over the ACD so you can tighten the yoke without opening the ACD.
Regarding the Atomic Seat Saver- I have removed a hose from a B2 second stage after a very quick rinse (unpressurized) and found traces of water in the hose.

 

[craig1225]

Got to tell you. Would have thought by now that somene would have devised something better than a dust cap .

 

[halocline]

Got to tell you. Would have thought by now that somene would have devised something better than a dust cap .

Once more, there's nothing wrong with soaking most regulators with the dust cap. It's EXACTLY what they are intended for. I can't believe how frequently this topic comes up. If the cap doesn't seal, something is wrong with either the cap or the regulator. There is one exception that I've seen, it's those DIN caps that don't screw on, they're more like little soft rubber sleeves. I haven't seen one of those in a long time.

Regulators that shouldn't be soaked un-pressurized are ones that have seat-savers that physically separate the 2nd stage orifice from the seat, like atomics. To me this would be a deal breaker as far as buying the reg. Even so, a little clean fresh water in the hose or even ambient chamber can be easily blown out with a few blasts from a tank after soaking. I do this every time I soak my regulators.

The big problem is salt water infiltrating the ambient chamber, exposed threads, and 2nd stage chamber, and drying in place. Soaking, not dunking, a reg in fresh water allows the salt to get pulled out of tight spots by osmosis.

 

[buddhasummer]

I can't inhale from mine with the inlet wide open. I don't think this is a good test.

Well I tried to suck air through my friends Zenith and sure enough you are correct, it's not possible. So will have to agree with you that my leak test is not "always" appropriate. Cheers.

---------- Post added October 12th, 2014 at 09:46 PM ----------

Oh of course they are. Do you think that regulators would be sold with caps that would not allow the 1st stage to be dunked in a rinse tank? How dumb do you think these manufacturers are? Just do the vacuum test, try to pull some air in a 2nd stage with the cap securely in place. Unless there is a leak in the regulator or the octo has a seat-saver, you won't be able to pull any air. This means it's water tight.

Regarding the HOG owner who says he can't pull any air with the dust cap off, if your reg does not have one of these auto-close devices, and you really can't get any air, maybe something's wrong. My guess is that you're just not sucking hard enough...


I'm not a fan of the oceanic style auto close device. It's basically a little ball on a spring that opens and closes with each breath. IOW, it's essentially another valve that is totally un-necessary, and if it fails or sticks, it could conceivably block air flow from the tank. That's not something you want. I'm not very familiar with the aqualung style, but my understanding is that the tank valve physically prevents the thing from closing off the regulator while it is attached to a tank. That would certainly be an improvement over the oceanic style. Still, how difficult is it to simply remember to put the cap in place?

I too was skeptical so tested my friends Zenith and sure enough you cannot draw air with dust cap off. I was sucking so hard I almost blew a blood vessel. So I guess they are designed that way of there is a design fault? Given it breathes fine when pressurized I'm going to assume it's by design. Chris? Jim?

 

[redacted]

I can't inhale from mine with the inlet wide open. I don't think this is a good test.

Well I tried to suck air through my friends Zenith and sure enough you are correct, it's not possible. So will have to agree with you that my leak test is not "always" appropriate. Cheers.

That is a bit alarming. You might want to check and see at what supply pressure it stops delivering gas. And WHY???