Oceanic regs

[pepperbelly]

If I do buy another 2nd stage reg I plan on using this Delta2 on the octo instead of that little genesis that's there now.

 

[DazedAndConfuzed]

The Delta 2 is mechanically instead of pneumatically balanced. That is, there is no net surface area pushing against the valve and all pressure exerted on it is by the spring loaded pin in the adjustment knob. It was a great design when it came out since a pneumatically balanced 2nd stage cost a fortune, but its price has been dropping to the point that the Delta 5 is now pneumatically balanced.

 

[halocline]

The Delta 2 is mechanically instead of pneumatically balanced. That is, there is no net surface area pushing against the valve and all pressure exerted on it is by the spring loaded pin in the adjustment knob. It was a great design when it came out since a pneumatically balanced 2nd stage cost a fortune, but its price has been dropping to the point that the Delta 5 is now pneumatically balanced.

As far as I can tell, it's just a downstream design with a spring loaded user adjustment. That's from the schematic in the Harlow book. There's still plenty of downstream force on the valve. This looks just like that genesis 2nd stage, which I suspect was modeled after this one.

The difference with balanced 2nd stages is that IP air is re-routed to counteract the downstream force. This means that the spring can be much lighter, and most significantly, when IP changes, so does the balancing force. This also allows the reg to work well within a range of IP adjustment. I wouldn't equate this design with that, as the spring from the adjuster is not responsive to IP.