Different brand 1st and 2nd?

[herman]

sometimes no, my mares 1st will not work with other seconds, they just free flow. my us diver works with anything, I have a french reg that takes anything. and maybe others but those are the ones I have tried.

I agree with Jim, something else is wrong...if your Mares happens to be a MR-12 it for all intents and purposes is a Conshelf (same basic internal design and parts). Reguardless, IP is IP as long as it's within the same range the make, model or brand of reg does not matter, seconds have no way of "knowing" what first they are connected to other than IP pressure.

 

[spectrum]

sometimes no, my mares 1st will not work with other seconds, they just free flow. my us diver works with anything, I have a french reg that takes anything. and maybe others but those are the ones I have tried.

You just have a mismatch of existing adjustments and got lucky with some combnations. IP falls int a general range of about 20 PSI and will vary with model and set-up. The second stages need to be dialed in to work with that IP. If you use an 1st with an IP higher than what the second were tuned to it will freeflow. If you go the other way it may breathe hard. If they are close you got lucky. It's usually an easy adjustment if you are so inclined.

---------- Post added July 2nd, 2013 at 07:26 PM ----------

Yes, as long as you use a primary reg and the secondary reg is designed specifically to be used as a back up/octo. The octo's have different sensitivity settings compared to a primary reg and are less like to free flow.

The only functional difference between a primary and an alternate is a partial turn of the cracking adjustment. Settings are different for sure but not necessarily design.

 

[windapp]

Whatever your regulator choice, they need to be serviced, so be sure that whoever will be performing the service is willing and able to service all of the regulators on the set. I have a US divers Octo, a Scubapro First stage, a Scubapro primary second stage, I don't remember the brand of my SPG but it is not US divers or Scubapro. When I bought my MK17, I adjusted the second stages myself.

 

[ev780]

It's best not to mix with Poseidons but other than that have at it. Remember that any new combination is subject to tuning to work with the IP of the 1st stage.

I have had an AquaLung octopus on my Poseidon for 15 years or so. Works fine and the tech has never once said anything about it at service time. Works like a charm.

 

[toddthecat]

sometimes no, my mares 1st will not work with other seconds, they just free flow. my us diver works with anything, I have a french reg that takes anything. and maybe others but those are the ones I have tried.

That's interesting. I have a Mares MR22 with a Scubapro S600 on it and it works flawlessly...

 

[dmoore19]

I have a MK25 with a A700 as the main second and I ran a Sherwood SR1 second for my Octo with no problems. I have since bought a Scubapro R095 for my Octo.

 

[spectrum]

I have had an AquaLung octopus on my Poseidon for 15 years or so. Works fine and the tech has never once said anything about it at service time. Works like a charm.

The catch I believe is hanging Poseidon 2nd stages on another brand's 1st stage. Poeseidon is the only common brand based on upstream valves. This means that the second stages will not "fail" into free flow if the IP creeps up. This does not apply to all models from what I just checked and only matters if primary and secondary are upstream Poseidons.

Where all comon downstream second stages are defacto over pressure valves Poseidon employs an integrated OPV in their 1st stage to prevent LP hpose over pressurization.

That is the basis for my comment. It can be OK but not in all cases, hence some detailed knowledge is needed beyond saying you can swap anything.

Pete

 

[ev780]

The catch I believe is hanging Poseidon 2nd stages on another brand's 1st stage. Poeseidon is the only common brand based on upstream valves. This means that the second stages will not "fail" into free flow if the IP creeps up. This does not apply to all models from what I just checked and only matters if primary and secondary are upstream Poseidons.

Where all comon downstream second stages are defacto over pressure valves Poseidon employs an integrated OPV in their 1st stage to prevent LP hpose over pressurization.

That is the basis for my comment. It can be OK but not in all cases, hence some detailed knowledge is needed beyond saying you can swap anything.

Pete

Got it.