Auto Closure Device

[buddhasummer]

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

Good idea, will look into it further. Cheers.

---------- Post added October 12th, 2014 at 11:32 PM ----------

I'll start a thread over in HOGs forum.

 

[halocline]

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?

I have no idea why this would be the case, it appears on the website that it's just a normal downstream balanced 2nd stage. Try sucking some air from just the 2nd stage, i.e. remove it from the 1st stage. If you can, also try pulling some air directly from the 1st stage with another 2nd stage that you can pull air from. I'd be interested in knowing. My guess is that there's some sort of auto closure in the 1st stage.

 

[buddhasummer]

I have no idea why this would be the case, it appears on the website that it's just a normal downstream balanced 2nd stage. Try sucking some air from just the 2nd stage, i.e. remove it from the 1st stage. If you can, also try pulling some air directly from the 1st stage with another 2nd stage that you can pull air from. I'd be interested in knowing. My guess is that there's some sort of auto closure in the 1st stage.

Thanks for the suggestions, am diving with the Zenith owner this Saturday will do as you suggest and post back.

 

[redacted]

I have no idea why this would be the case, it appears on the website that it's just a normal downstream balanced 2nd stage. Try sucking some air from just the 2nd stage, i.e. remove it from the 1st stage. If you can, also try pulling some air directly from the 1st stage with another 2nd stage that you can pull air from. I'd be interested in knowing. My guess is that there's some sort of auto closure in the 1st stage.

The 2nd is a balanced barrel poppet (downstream) design which should allow a slight flow under vacuum. I did not see anything in the schematic that looked odd.

I could not find a schematic for the D1 or D3 1st. But a diaphragm reg should also pass some flow under vacuum with the inlet open.

 

[buddhasummer]

I have no idea why this would be the case, it appears on the website that it's just a normal downstream balanced 2nd stage. Try sucking some air from just the 2nd stage, i.e. remove it from the 1st stage. If you can, also try pulling some air directly from the 1st stage with another 2nd stage that you can pull air from. I'd be interested in knowing. My guess is that there's some sort of auto closure in the 1st stage.

I did as you suggested, I could not draw any air. I will post over in Edge/HOG forum this weekend as now I'm really curious. Cheers.