Mixing Brands?

I have recently won a Sherwood Insight CR2705 DC. It came in the console with a pressure gauge. I already have a DC and regulator setup so I am considering giving this computer to my brother who doesn’t have any scuba equipment. My question is can he buy a regulator/octo setup that isn’t Sherwood to use with this console? I have read that it isn’t smart to mix brands, but that may just be between the first and second stages, not pressure gauges and first stages. Any help would be appreciated. Thanks for your time.


John

I feel you can. I rarely see the console brand match the regulator 1st stage. If you do a few searches on SB, I am sure you will find most of us mix nearly everything. I have seen first stages/primary second and octo from three different brands. Personally, I try to match first stage and primary second. Outside of that, anything goes.

Tom

A different console on the high pressure hose should be no problem. The only 'gotcha' I can think of is that you can't put a 220 bar SPG on a 300 bar system; other than that it shouldn't be an issue.

1st and 2nd stages have a few more 'gotchas'. Generally you can mix and match except for the non-standard brands like Poseidon. Most 2nd stages work around 9 bar and most 1st stages use this too but you need to check before trying.

jnickell:

I have read that it isn’t smart to mix brands, but that may just be between the first and second stages, not pressure gauges and first stages.
John

Click to expand...

Any idea what this is not a good idea? I would be interested to know what justification was given for not mixing brands.

I assume the dive computer is just going along for the ride and does not "know" what the rest of the system is.

Typically most octos will work with most first stages. If they do not work well they may free flow or breath hard. Both of which you could check out on a quick pool dive. These problems are usually the result of the intermediate pressure from the first stage being too high, or too low for the octo. In most cases the octo can be adjusted to work with the first stage. That is usually done in annual service. The adjustment is changing the tension on the second stage poppet spring by turning the nut that loads it.

Also, while unlikely, it is possible for very old or some European octos to have incompatible threads. Adaptors are available, but in that case a same brand octo might be the easier way out.

Mr Carcharodon:

Any idea what this is not a good idea? I would be interested to know what justification was given for not mixing brands.

Click to expand...

There are some Poseidon regulators that are best used with their own kind. Other than that 1st stages, primary and alternate second stages can be mixed freely and adjusted to get along.

Another reason for not mixing is for the sake of serviceability. If your air delivery can't be serviced at a common dealer it can get ugly. BCs and dive computers either do not get serviced or are stand alone items that can be different without much pain.

Pete

Elaborating a bit on Spectrum's comments ........

The 1st stage converts the tank pressure down to an intermediate pressure. The 2nd stage is fed by this intermediate pressure. As long as the intermediate pressure is in the correct range, then the 2nd stage will operate properly.

Almost all 1st stage regulators have IP around 130 to 150psi, other than a few oddballs such as the Poseidon brand with its high IP; and 1st stages of any brand where the IP has purposefully been set to a lower IP in the 120psi range to minimize icing and freeflow problems of the 2nd stages it feeds.

Some cheap unbalanced 2nd stages that are used as octos are more sensitive to the intermediate pressure and might need readjustment for a primary regulator that is set to a particularly high or low IP. This isn't really a problem of mixing brands between 1st and 2nd stages --- you can also run into this problem when swapping between 1st stages of the same brand since they will vary a bit according to how they have been adjusted and how the IP has drifted while in service. Balanced 2nd stages are relatively insensitive to changes in IP, and can more readily accept the changes caused by swapping around 1st stages.

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Dive computers and pressure gauges are totally independent of the 1st stage and there is no problem at all in mixing brands.

The inflator on the BCD is powered by the intermediate pressure, but is not really affected by the exact IP, and again you can mix and match at will.

As Pete said the biggest issue with mixing most brands of first and second stage is during service if you use an LDS for service. If your octopus is of a different brand the LDS who is authorize to service your primary regulator may not be authorized (or may not want) to service the octopus. In most cases it shouldn’t be a problem, but I am sure there are plenty of LDS where it would be a problem.

For this and many other reason, I service all my own gear. Heck, my wife’s regulator is an Aqua Lung Titan first stage, a Scubapro D400 second stage, and a Oceanic Slim Line Octopus. Both our pressure gauges are brass XS Scuba gauges and BC inflator is Sherwood. I use most of the time a Phoenix Royal Aqua Master with an Oceanic Swivel Octopus.

I do have an Aqua Lung Titan first stage set up with an IP of 175 psi that I use with my Poseidon Cyklon 300 second stage and octopus. It works just fine in that combination. Granted, I seldom ever use it, but it works.

I went back to see where I got this idea from. Looks like it came from Scuba Diving magazine. I hope this is O.K. but I posted the link from which I got the information. If you look at tip “10” you will see it says “Don’t mix brands”, but it appears they are referring more to first and second stages nothing to do with pressure gauges.

http://www.scubadiving.com/gear/general_gear/article3524

In that case and in light of what you guys have told me I now have a new question ( let me know if I should start a new post). Since my brother will now have a DC and a pressure gauge, what regulator/octo do you recommend? I under stand that most people will recommend the reg they dive, if not just to justify their purchase of that reg. I have done a little research and feel that these three regs would suffice. My brother will be doing mostly tropical water dives on vacation but some cooler water dives here in Colorado ( 55 – 60 F). Here is what I have come up with in the price range he wants to stay in.

Oceanic GT3 Regulator with CDX-5 First Stage (Non DVT) - $229.00
Mares Proton 16 Metal Regulator – $249.99
Zeagle Envoy Regulator – $279.45
Apeks XTX20 Regulator – $249.95
AquaLung Titan LX Regulator - $264.95

As you can see, we are looking to stay below $300.00 for the First and second stage, and hopefully work out a good deal for the octo. Please, let me know what you think of these regs and any others you think would be in this class. Thanks again for your time.

John

Any of them seem to be great regulators. But I am kind of biased towards the Titan. It is the only regulator in the list that is using first stage parts and design that have been around for over 40 years. They have changed the geometry of the body and made many minor improvements over the years (in seat materials, etc.) but the basic design is basically “bulletproof” and a great performer. You can also get service and parts for it anywhere in the world.

Although I am not familiar with this second stage, I like the pneumatically balanced second stage design.