Mixing & Matching Regulators...

[DA Aquamaster]

I'm looking to get another 1st and 2nd stage...currently dive APEX ATX 100 1st & 2nd stage with and ATX 40 octo...

...If I get another brand other than APEX, am I going to have any problems?

I'm currently eyeballing a ScubaPro MK25/S600 set up and putting the MK25 on the pony, the S600 on my current Apex 1st stage.

It won't present any mechanical problems as long as you have the second stage tuned to the first stage's IP. (Something you'd want to do even if you added an Apeks second stage.)

It may present some service issues however as you'd need a dealer that serviced both SP and Aqualung/Apeks regs.

Not necessarily true. Some of the Apex regulators use a larger connection and hose for the primary second stage. This port can be plugged and you can still use the other standard sized low pressure ports for standard 3/8" low pressure hoses.

A 1/2" LP port is a pain and is generally a fad that has thankfully passed. However the hose connection at the second stage end of the hose is still the same standard fitting. So you can use any second stage you want as long as you use it on the end end of the Apex hose, or alternatively put the smaller 3/8 LP fitting into one of the 3/8" ports.

BTW, don't mix Posiedon First stages with ANYTHING ELSE. Different beasts (up-stream) and you could hurt yourself.

No...All diaphragm first stages use an upstream design where the seat carrier is on the upstream side of the high pressure orifice. But it does not matter as if something fails, it is not going to get any higher than tank pressure above the orifice and downstream of the orifice a high presure leak is a high pressure leak whether it is coming from an up or downstream valve design.

However Poseiden second stages use an upstream design that will not vent the excess pressure caused by a leak in the high pressure seat in the first stage. Consequently a poseiden second stage hose incoporates an over pressure relief valve. If you use an upstream posiden second stage on something other than a poseiden hose, you will want to add an opv to one of the other LP ports.

The older Cycklons opertated at a higher intermediate pressure and that can create compatibility problems.

 

[The Chairman]

Mea culpa... that should have read "Don't mix Posieden SECOND stages with ANYTHING ELSE!" Sorry for the typo.

 

[sk8rpj]

Poseidon is crap anyway. If you just stay away from it you wont have any problems. Dive shops sell poseidon because they have a great profit margin on it and can convince new divers that it is best for them.

 

[a1a9]

Help me understand. I wanted to buy a Poseidon Jetstream/Odin Regulator 1st and 2nd stage and use my Atomic SS1 for my octo/inflator. Will this work?

 

[Packhorse]

So its the hose itself that has the pressure relief valve? So you could use a posiedon 2nd with another 1st stage brand as long as you used the poseidon hose? What if you used a non poseidon octi on this setup (SS1) would this act as a pressure relief?

a1a9 A small problem I had with my SS1 was that on my SP MK20 1st it would have a slight free flow on the surface. on my AL Cousteau SEA 1st it didnt. I could only conclude the IP on the SP was higher than the AL.

 

[The Chairman]

Packhorse, a1a9...

The IP used on the Posiedon regulators is MUCH, MUCH higher than your atomic. I don't have the manual in from of me, but I believe it's like 170 psi or so while typical regs operate with an IP of 125-145psi. IOW, mixing these regs will make one a hard breather and the other a free flower. Adding the second stage to the to a non Posiedon first stage will require it to be set outside of it's operating range, which is probably a bad idea.