Questions about Apeks AT20 2nd stages

[elgoog]

Hi all -

Someone at work was clearing out their dive locker last week and has a pair of AT20 2nd stages still available for SUPER cheap. If I do manage to get them before they're gone, I would pair them with something like a new HOG D1 for use in NorCal (or something suitable for cold-ish water from eBay). I did some poking around on SB and looked at the parts manual and diagram for the AT20 and had some questions.
1. Would the AT20 be OK to use in 50F water as is?
2. From the Apeks parts diagrams of the higher model 2nd stages, it looks like the heat exchanger is a different part from the tube (valve spindle?). Is this tube in the AT20 metal or plastic? From what I've read about 2nd stages in general, it seems like having a metal tube is better for colder water as it has some condensation which helps with dry mouth. I'm unclear on what the heat exchanger actually does on the Apeks if the tube is metal.

I know you can upgrade the AT20 and add the heat exchanger but that will mostly negate any price advantage and I might as well get a full new HOG set at that point.

Thanks in advance,
elgoog

 

[reefrat]

Hi
It's sounds like you're having fun with this and that is a slippery slope toward becoming addicted to tinkering with these things!! Ask me how I know!
The concept you are describing is sound and the AT20 2nd stage is as good as any that Apeks, makes but it has the smaller exhaust tee (from memory) which works OK but is not the best for keeping exhaust bubbles out of your face when looking horizontally. Financially feasible? If you are buying all new components (especially the heat exchanger which I would think mandatory for lkess than 50F) then I would be surprized if it works out cheaper in the end than a lower priced but good value straight-from-the-factory complete reg like something from Edge epic, Hog, Oceanic, Aqualung or Mares and a few others. In addition, and from a purely practical perspective I have come to appreciate the simplicity and efficiency of staying with one manufacturer for a regulator set, mixing and matching within the one manufacturer is OK, but buying a proven and well received reg package from the right dealer is usually still an easy and cost effective option if you research and shop around.

 

[tbone1004]

you don't need the heat exchanger for 50F water. Cold water means sub 40F where the pressure differential from IP to ambient causes a severe temperature drop and will freeze the internals. You want a metal barrel because it has enough thermal mass to keep it from freezing. 50F isn't cold enough for it to be of concern.

The AT20 is a great regulator and all you need for most diving, the barrel is metal and identical to the ATX50/100/200 aside from the adjustment knob. If you are planning on buying HOG first stages you may as well buy the D1 Classic and use the AT20's as your secondary.

Hog D1 Regulator Set - Dive Right in Scuba
$180 for a first and second, good deal. AT20 should be worth $50-$60 probably.

 

[elgoog]

It's sounds like you're having fun with this and that is a slippery slope toward becoming addicted to tinkering with these things!!

Heh, yeah - for now, the primary reason for all this is staying under budget. My wife dives as well and anytime I get gear, I have to buy 2 sets. So, always on the lookout for a deal, used or otherwise ...

Financially feasible? If you are buying all new components (especially the heat exchanger which I would think mandatory for less than 50F) then I would be surprized if it works out cheaper in the end than a lower priced but good value straight-from-the-factory complete reg like something from Edge epic, Hog, Oceanic, Aqualung or Mares and a few others.

you don't need the heat exchanger for 50F water. Cold water means sub 40F where the pressure differential from IP to ambient causes a severe temperature drop and will freeze the internals. You want a metal barrel because it has enough thermal mass to keep it from freezing. 50F isn't cold enough for it to be of concern.

Not looking to add anything to the AT20 - only reason I was considering buying it was if it was practical as is (which it seems like it is)

In addition, and from a purely practical perspective I have come to appreciate the simplicity and efficiency of staying with one manufacturer for a regulator set, mixing and matching within the one manufacturer is OK, but buying a proven and well received reg package from the right dealer is usually still an easy and cost effective option if you research and shop around.

Cobbled together regs are the price I'm OK paying for staying under budget. I asked around and service on something like this isn't more expensive around here.
More than same manufacturer, I'm trying to stay within the combo of manufacturers serviced by the LDSs around here for the used gear I'm looking at.

The AT20 is a great regulator and all you need for most diving, the barrel is metal and identical to the ATX50/100/200 aside from the adjustment knob.

Awesome!! Exactly what I was hoping to hear.

Thanks for all the information,
elgoog

---------- Post added November 17th, 2014 at 08:21 PM ----------

Sheesh, both AT20s went for close to $200 - too much for my wallet even though they included 2 service kits for the next maintenance. There was also an ATX200 1st and 2nd + a Zeagle T50D 2nd package (no hoses or SPG) that ended up going for $450 - great cosmetic condition but not used/serviced in 2-3 years. Seemed kinda high but I'm learning that Apeks/Zeagle in the used market goes quick!! And for mucho $$$$.