DIR regulators...?

[VaPadiDiver]

Thank you for the correction LUBOLD. After researching it more yesterday I came to the same conclusion as you. My only question is what is the common thought on the Flathead first stage? The hose routings seem to be ideal but if I show up in a DIR class I don't want to be told I need to change them out. I do my DIR-F class in May but may consider Tech 1 or ever Cave w/ D.R.

 

[reubencahn]

Thank you for the correction LUBOLD. After researching it more yesterday I came to the same conclusion as you. My only question is what is the common thought on the Flathead first stage? The hose routings seem to be ideal but if I show up in a DIR class I don't want to be told I need to change them out. I do my DIR-F class in May but may consider Tech 1 or ever Cave w/ D.R.

I don't think you have anything to worry about. I'm pretty certain that for DIR-F, the only equipment requirements are bp/w and longhose. Everything else is negotiable. Some equipment choices might be criticized but will not be a bar to completion. As to regulators, in my DIR-F class, there were Apeks, AL, and Scubapro regulators. The only requirement for the regs was no upstream seconds. I understand that the equipment requirements become more strict as you move up through the certs. But even so, I think the only additional requirements for regs would be good hose routing and a second that could be disassembled without tools.

 

[MarcHall]

I don't think you have anything to worry about. I'm pretty certain that for DIR-F, the only equipment requirements are bp/w and longhose. Everything else is negotiable. Some equipment choices might be criticized but will not be a bar to completion. As to regulators, in my DIR-F class, there were Apeks, AL, and Scubapro regulators. The only requirement for the regs was no upstream seconds. I understand that the equipment requirements become more strict as you move up through the certs. But even so, I think the only additional requirements for regs would be good hose routing and a second that could be disassembled without tools.

DIR Regs

In my personal observations the most common regs that get used in DIR configurations are Apeks (typically US4/DS4 and TX50 combinations) and Scubapro (typically MK20/MK25 firsts and G250 or S600 seconds).

The general consensus seems to be that the Apeks are less expensive and a bit more reliable then the Scubapros. The Scubapros probably breath a bit better then the Apeks and use standard ports.

Since we switch to less dense gases as we dive deeper having the ulitimate breathing reg is less important then having something that is reliable. Personally I like to use the same second stage on necklace reg as on my primary, because when I need to share air with my buddy I get to breathe the necklace reg, its a selfish thing :->

That said I have all Scubapro regs partially because of some excellent keyman pricing, partially because I used to dive with one of the Scubapro engineers on a regular basis and partially because of the wide range of stores selling and servicing Scubapro regs. I am currently using MK25 firsts and S600 seconds on my backgas regs and MK25 firsts and a mixture of G250HP and S600 on my deco/stage regs. My buddies either dive Scubapros or Apeks regs.

I do believe that no matter what your regulator choice, it is a good idea to take into consideration the ability to get a reg serviced in the future. Apeks and Scubapro have been around for a quite awhile.

It is a good idea to standardize on one reg for all of your regs. As your regulator collection grows you can use them interchanably. If a stage regulator fails you can convert one of your backgas regs easily by just switching out to the properly length hose. You need to keep fewer spare parts around if all of the regs are the same. Buying a cheaper, lower erformance reg for your 20 foot deco bottle is not a great idea as we might t some point need to use that reg on a deeper stage bottle.

Having standard hose fittings eliminates the need for adaptors and an addiational failure point of an extra O-ring. Using standard hose fittings increases the abilitity to interchange hoses. If your're standard hose fails you are more likely to be find a replacement amoung you're dive buddies spares.

The second stage should be of a design that you can easily remove the cover and get to diaphram for field or in-water fixes.

Hose routing is important and it is can be difficult to route all of the hoses cleanly in a single reg configurations.

Enjoy

Marc Hall
www.enjoythedive.com
www.sdue.org

 

[PacerFan577]

I was looking at the ScubaPro Mk16. Any recommendations for or against this reg? I noticed someone mentioned the Mk25 is one more popular first stages, but wasn't sure if there was a reason people weren't looking at the Mk16. Thanks!

 

[DA Aquamaster]

The Mk 16 is potentially better suited to cold water water than a Mk 25. The ambient chamber is not sealed but it is fairly well isolated from the rest of the reg and is exposed to a large amount of water flow. You would also need need significant accumulations of ice to lock up the main spring or the diaphragm and that would eb unlikely to happen given the heat transfer that would be occurring.

The flow rate is also lower at around 90 scfm compared to close to 300 scfm for the Mk 25. That is good news for cold water use as it drastically reduces the potential adibatic cooling load but theoretically could be a problem for very deep dives. In reference to other SP regs, the Mk 16 is only a medium performance first stage.

Then again I have corresponded with some cave divers who use the low performance Mk 2 and swear by them at depth as long as helium mixes are being used. They feel the helium slips through them very nicely at depth. My conclusion is that if you are deep enough to be concerned about the flow capacity of the Mk 16 on air, you really should be using trimix anyway and then it should not be an issue.

I have not used one though and cannot comment on how ammenable it would be to proper hose routing.

 

[JPBECK]

When I dive Open circuit I use double Atomic B2's without sorry swivel---Breath nice really reliable!
Nice Regs

 

[jbb]

When diving an H valve single or double. I understand that the DIR recommendation is that the octopus first stage be a diaphram operation rather than a piston first stage. (I believe it is in the GUE fundamentals book) Is this absolutely necessary? The reasoning being that the diaphram is more durable and fail safe? I dive a Atomic B1 primary like the DIR configuration but if I take a technical class in the next year or so, I would like to stay with the same manufacturer equipment and Atomic does not have a diaphram 1st stage.

Jason

 

[MarcHall]

When diving an H valve single or double. I understand that the DIR recommendation is that the octopus first stage be a diaphram operation rather than a piston first stage. (I believe it is in the GUE fundamentals book) Is this absolutely necessary? The reasoning being that the diaphram is more durable and fail safe? I dive a Atomic B1 primary like the DIR configuration but if I take a technical class in the next year or so, I would like to stay with the same manufacturer equipment and Atomic does not have a diaphram 1st stage.

Jason

If you are happy with your Atomic reg then I would go ahead and purchase a second one for you doubles configuration.

The most common first stages I see in DIR configurations are Scubapro pistons (MK25) and Apeks diaphrams (US4/DS4). Typically divers use the same first stage on both the left and the right post. Currently I use the Scubapros.

The one concern I would have with Atomic regs is the use of titanium in high 02 environments - above 40% 02. Although you are planning on using these for backgas where the 02 would always be lower I find that over time my regs tend to migrate to serve different purposes. Regs purchased for backgas might be replaced and then be used for stages or deco bottles. Titanium and high partial pressures of 02 don't play well together as one of my buddies in his pre-DIR days discovered with an Atomic T1 and Nitrox 80.

If a remember correctly Atomic approves only it's Monel version for mixtures up to Nitrox 80. Atomic does not approve any of their regulators for use in 100% 02 environments.
DIR deco gases include Nitrox 50 and 100% 02.

Marc Hall
www.enjoythedive.com

 

[dc4bs]

O.K...I can't speak to the rest of your question, but I can answer this part.

Why does it matter if the reg is "updise down"? How could that possibly affect performance? Answer...it doesn't matter (to the best of my knowledge)

Using the Apeks ATX100/200 1st stage "upside down" or sideways won't affect performance at all.

Something to think about is the environmental seal though. If it's "upside down", that soft seal will be pointing "up" and could be damaged if you hit an overhead object with it.

I'm prety sure this should not cause the regulator to fail if this happened. It should continue to operate as a standard non-environmentaly sealed reg until it was serviced and had the seal replaced. In cold water, the 1st stage would become much more likely to freez up though.

I have 2 ATX100s that I position like this: / \

All hoses connect to the "inside" ports of the regs. Currently, I am using the 1/2 inch port on the left shoulder post with the Apeks hose and carry a spare hose with me. I need to get a pair (1 spare) of shorter hoses for this...

 

[ddown]

Does anybody have any reliabilty evidendence to back up this Apeks reliabilty claims? I would think in thirty years or so the Scubapro has proven it's record. What is the Apeks based on Opinion or the DIR Mantra--recommendations.