What is this 2nd stage and how do I unscrew the cover?

[Fishpie]

I have two RS-790 rigs (basically SP MK17 S550) with Octos that are not shown on your site.

The Octos appear to be balanced barrel poppet design with what looks like an automatic depth (pressure) activated venturi like the Atomic 2nd stage....not 100% about this it could just be a factory set venturi with a blanking plate instead of the usual knob/lever.
They have a flip-up access cover to the exhaust valve. They are round (not oval) shape and have a cracking pressure adjustment knob.
The venturi has to be unique to this second stage.

.....I can't get the purge covers unscrewed.
I don't see any pins or other retaining clips to stop them from being unscrewed.
Before I get out the strap wrench I would like to confirm that they have a standard thread and are not reverse thread like an early TUSA 2nd stage.

Thanks in advance for any info.

 

[TUSA]

HI-
From your description it sounds like you have the SS-65 octo. The front cover can be removed by turning the retaining ring 1/16th counter clockwise to unlock, then pull the ring and cover straight out. This should release the ring and cover.
If you have any further questions please let us know.

 

[Fishpie]

Yes, that's the one.
However the ring and cover look to be a single piece design and I can't get it to budge.
From what you said I take it that the cover isn't actually threaded and screwed on like the S-90 but should pull off once turned a bit anti clockwise to unlock it?
Is there any special trick to get it off.
Thanks for your help.

 

[Peter_C]

Must not be exactly like an S550 then, since it uses a pin. Good to see the manufacturer set up and help

 

[Fishpie]

The primary S 90 is the same as the S 550 and has the pin.....it also has a nice bright red retaining clip for the barrel which makes it easy to spot after flying across the room, the SP ones I've seen are "loose-me" black.

From what I found out the octo is the SS-65 which had rather a short life with TUSA.

 

[redacted]

Covers with that type of retainer system might need a little inward force before they will turn.

 

[Fishpie]

I thought that this one was going to defeat me....but I eventually got the covers off the second stages.
They're really a well made reg with a couple of poor features.
I have to make the cover a detracting feature and the other being the factory set venturi....in the "minus" or surface position. This is fine for their intended use as an octo but they deserve a chance to be better.
Otherwise they are a well made typical barrel poppet balanced adjustable second stage with metal barrel and oriface.

I can't help thinking that one of the reasons it didn't last long in the line-up was that its potential performance might have embarrassed some of the more expensive regs in the range.

Thanks again to the manufacturer for answering my questions and I have to say that your regulator range has to be ranked amongst the best.