what regulator to purchase?

[ams511]

If what I said was incorrect, I would be VERY happy to have someone correct me! Particularly, if the 1st being "overbalanced" does not mean what I think, I would really like to know what it does mean.

First, there is no additional maintenance required for a piston regulator. You soak it the same as the diaphragm regulator. The only advantage is if you want to go ice diving then it does not need to be packed with grease. Piston stages in general flow more air but a good diaphragm regulator flows more air than a diver needs. Second, additional HP ports are also good for hose routing for divers that mount the first stages horizontally rather than vertically. This is especially good for doubles. Third, you are correct that overbalancing should increase the intermediate pressure the deeper you are diving but Tbar is also correct that this could lead to free flows which means may need to detune. Also because the second stage is also balanced I am not sure what actual benefit overbalancing has because in theory the second stage should compensate for changes in IP. Many divers think overbalancing is nothing more than a marketing ploy. Fourth, the adjustability of the second stage allows the diver to detune the regulator to reduce free flows while diving. As far as breathing effort goes there is no difference from a property tuned non-adjustable regulator and its adjustable counterpart. Fifth, The dive pre-dive switch directs the air into your mouth when in the dive position. It does not adjust inhalation effort, it just feels that way. Sixth, second stage balancing means the cracking pressure should be constant over a range of intermediate pressures. This allows finer tuning and a better breathing regulator. Seventh, I know of no regulators that are mechanically balanced, all the balanced regulators I know of are pneumatically balanced. What some manufacturers refer to as mechanical balancing really means an unbalanced down stream design. Eighth, Hollis is the family name of the owners of American Underwater Products. Hollis is their "tech" line and Oceanic is their recreational line while Aeris I believe was their attempt at a "value" line. My understanding is that Aeris will be folded into Oceanic.

 

[NC Air Hog]

There is a lot of great advice on here already. I would throw in that spending the little bit extra on a sealed first stage will be well worth it in the long run. Keeping all of the salt water off of the inner spring will allow it to last longer and function better over time. That is my two cents worth. I think, and could be wrong, that DRIS will ship to your area. Those guys are great to work with.

 

[stuartv]

Seventh, I know of no regulators that are mechanically balanced, all the balanced regulators I know of are pneumatically balanced. What some manufacturers refer to as mechanical balancing really means an unbalanced down stream design.

I read elsewhere on here that the Oceanic Delta 4 is mechanically balanced.

 

[ams511]

I read elsewhere on here that the Oceanic Delta 4 is mechanically balanced.

Looking at the schematic I am almost certain the second stage is unbalanced. I am familiar with the thread where that was mentioned and others disagreed with that assessment. Again there is no definitive definition for what it means to be mechanically balanced. Honestly I have no idea how you could mechanically balance a regulator because the IP and ambient pressure can vary but the spring rate would remain constant. Most regulators that claim to be balanced are pneumatically balanced, so saying it is pneumatically balanced isn't really adding anything. If you look at Oceanic's description of the Delta 4 they never really say it is mechanically balanced they talk about the adjustment system, they also claim it is patented but the patent must have run out because the original deltas were out in the late 80s or early 90s. My first octo was a delta and that was 1991 or 92. Adjustable non-balanced regulators are rather rare besides the Delta, there is the Sherwood Maximus, Kirby Morgan Superflow, Scubapro M50, and Scubapro C300. There is also a Scubapro 109 but that used a barrel poppet design like balanced regulators and can be upgraded into one.

 

[wolflegresley]

I would recommend the Apeks XTX line. You will be hard pressed to find someone say something negative about those regs!

 

[diversteve]

There is nothing on this page that I wouldn't dive with.
Since they're in Sydney maybe you can check them out: Regulators | Frog Dive Australia

This appears to be a nearby Scubapro dealer also: Scuba Warehouse | Regulators

And another local option: PRO DIVE Online Shop - Regulator

Apeks/Atomic/Scubapro make quality gear also at a slightly premium price. Here in the states that's partially off-set by Atomic's 2 year standard service interval which I believe would apply there as well. I'm a little shocked at the price differential though compared to what we pay here although that may be the exchange rate also.

You might also price some of it purchased overseas. As long as you have a local dealer, they should be willing/able to service it. In the U.S. - two of the big online retailers - Scubatoys or Leisurepro.com ship internationally. From Spain there's the Diveinn superstore. Do verify warranty coverage though - sometimes that changes per country. Often for EU goods purchased here in the U.S. so may not be as big a issue for you.

 

[Aqua-Andy]

Many divers think overbalancing is nothing more than a marketing ploy.

Actually overbalancing is a design flaw that became a marketing ploy.

 

[scubadada]

Since you're diving in salt regularly, I'd go with a sealed diaphragm regulator, that rules most of Scubapro out btw, not that pistons are bad, but cleaning sealed diaphragms is much easier and they are more tolerant of not being cleaned, pistons aren't, or they will require expensive and potentially messy packing with grease, not good eats.

What???

 

[tbone1004]

pistons, sealing=pack chamber with grease to keep water out, works well but is expensive during service and a general PITA, nonsealed means that salt water is in the chamber and is prone to corrosion and salt buildup. Unsealed diaphragms are the same, the difference is sealing diaphragms is super simple and inexpensive since it comes on most of the higher end regulators anyway. I dive an unsealed piston on my O2 bottle because for that use it is a superior design, but all of my other regulators are sealed diaphragms and since there is no real meaning in the performance differences between the two, the only advantage to a piston is during O2 use where it holds up better in the high O2 environment, but even that is pretty negligible for most divers and limited to CCR and deco bottles.

 

[ams511]

I think you are going overboard with recommending sealed regulators for warm saltwater diving. With proper rinsing and soaking there is no problem with salt or corrosion build-up. Scubapro has been making primarially piston regulators since the 1960s, would they still be in business if there was something inherently defective about the design? The Scubapro MK-5 is probably the most copied/cloned first stage in history, why would other companies copy a poor design? Many divers, myself included, have been using unsealed piston regulators for decades without a problem. Also most of US Diver/Aqualung's line was/is unsealed diaphragm regulators. Their early sealed models used some type of oil between the seal and the diaphragm that would sometimes leak. It was only with the Apeks regulators that mechanical transmission was used.

I agree with you that if someone needs a sealed regulator for cold or contaminated water then a sealed diaphragm or Sherwood/Genesis's dry sealing piston regulators are the way to go. But for warm salt or fresh water (over 50) any reputable regulator is fine.