First Regulator Set Purchase

[rhwestfall]

My diving is the Great Lakes & my kits are for cold water....

SP MK-17 First with any of the following seconds: [SP 109/156, SP G250v, SP S600 or HOG Zienith] OR HOG D1Cold First & Classic Seconds.

That being said, I just took delivery on a Poseidon X-Stream package. Waiting to try them out...

The only piston I have taken diving here is a de-tuned MK-10 (w/ no silicone packing) with a 109/156. Never had issues, even in ice. I did however see many "modern" SP pistons not do well below the thermocline (sub-45 degree). It was my reason to go with the MK-17. I will not use their pistons here anymore*.

* - I use a MK-2 for an emergency octo on a pony, and sometimes for DECO....

 

[JohnN]

Thanks all for all the replies! That has helped a lot! After careful consideration, I think I may not due the Ice Diving during the winter and only dive through Spring - Fall. Since some days here in Northwest Iowa, the windchill has gotten to -30 at times, a few times during the winter, and we get a lot of snow some years. So most likely, won't go out during that. But from what everyone mentioned and what I mentioned in the first post, about diving in 40*F-80*F water, would would you recommend, that would also work at Bonne Terre Mine, and other wonderful dive destinations in the world! Thanks for the great information everyone! I'll continue to research to help me determine the best reg along with all the wonderful information you guys provide! I really appreciate it!

Sealed primary stages are not just for cold water diving. To over simplify, if water doesn't get into the internals, your interval between servicing the regulators can be much longer. Purchase an IP (Intermediate Pressure) gauge and monitor that your 1st stage holds a constant pressure (for my HOG D1 about 145 psi). Base your service interval on how it is performing, not on the calendar.

 

[ams511]

Thanks all for all the replies! That has helped a lot! After careful consideration, I think I may not due the Ice Diving during the winter and only dive through Spring - Fall. Since some days here in Northwest Iowa, the windchill has gotten to -30 at times, a few times during the winter, and we get a lot of snow some years. So most likely, won't go out during that. But from what everyone mentioned and what I mentioned in the first post, about diving in 40*F-80*F water, would would you recommend, that would also work at Bonne Terre Mine, and other wonderful dive destinations in the world! Thanks for the great information everyone! I'll continue to research to help me determine the best reg along with all the wonderful information you guys provide! I really appreciate it!

Often times new divers overthink their first regulator purchase, the fact is that there is very little junk on the market anymore. Even the least expensive regulators perform fine and are reliable. Usually the best value is in the middle of the line and the worst is the top. Any regulator that works in cold weather will also work in warm weather, so you have no worries there.

If you want specific recommendations then I would recommend Apeks XTX-50/DST or XTX-40/DS4 or ATX-40/DS4. For Scubapro the MK-17/G260 is the best value and for Atomic the Z-3. I don't own Atomics but I do own Apeks and Scubapro regulators. In general, you want a sealed diaphragm first stage and a second stage with a metal air barrel. Other regulators such as Hog, Dive Rite, and maybe Hollis and Zeagle are other choices.

I would not worry about parts for life and service intervals. There is a sticky on this forum explaining how to check a regulator before a dive. Most regulators can go two years or more between intervals. However you do want to check before the dive. Most people find it is less expensive to bring the regulator in when it is acting up then bring it in yearly for a check.

---------- Post added August 11th, 2015 at 02:35 PM ----------

To over simplify, if water doesn't get into the internals, your interval between servicing the regulators can be much longer. Purchase an IP (Intermediate Pressure) gauge and monitor that your 1st stage holds a constant pressure (for my HOG D1 about 145 psi). Base your service interval on how it is performing, not on the calendar.

In no regulator I am aware of does water touch the "internals". The difference between a sealed and unsealed diaphragm regulator is that in the unsealed diaphragm water touches the diaphragm while in the sealed version there is a secondary diaphragm that "seals" the first one and transfers the water pressure using either oil or a lever. In neither version does water get inside the regulator.

Piston regulators are usually not sealed. The water only touches the piston and the spring. This can become a problem when the regulator is not properly cleaned after a dive allowing rust to form. Sherwood and Genesis use an air-bleed system to seal their piston regulators. Atomic and the older Scubapro regulators use lubricant.

Historically, most regulators were unsealed. Aqualung had a sealed version and Scubapro relied on lubricant. It was only when Apeks became popular (and showed you did not need oil to transfer pressure to the diaphragm) did other manufacturers jump on the sealed background. I can see no reason why sealed regulators would go longer between rebuilds than unsealed regulators (except for poor rinsing) nor do I know of any study that tested this.

 

[JohnN]

In no regulator I am aware of does water touch the "internals". The difference between a sealed and unsealed diaphragm regulator is that in the unsealed diaphragm water touches the diaphragm while in the sealed version there is a secondary diaphragm that "seals" the first one and transfers the water pressure using either oil or a lever. In neither version does water get inside the regulator.

Piston regulators are usually not sealed. The water only touches the piston and the spring. This can become a problem when the regulator is not properly cleaned after a dive allowing rust to form. Sherwood and Genesis use an air-bleed system to seal their piston regulators. Atomic and the older Scubapro regulators use lubricant.

Historically, most regulators were unsealed. Aqualung had a sealed version and Scubapro relied on lubricant. It was only when Apeks became popular (and showed you did not need oil to transfer pressure to the diaphragm) did other manufacturers jump on the sealed background. I can see no reason why sealed regulators would go longer between rebuilds than unsealed regulators (except for poor rinsing) nor do I know of any study that tested this.

So on a piston 1st stage that isn't packed with goo, water touches the shaft of the piston and can corrode the metal, abrading the O-rings that seal the chamber. Yes if you perfectly flush the reg every time, this is minimal, but this does present a failure mode that isn't present in a sealed diaphram style regulator. Ditto for sand, silt and junk in the water when you dive. not all of us have the privilege of diving in 80 oF water with 100 ft vis

 

[ams511]

So on a piston 1st stage that isn't packed with goo, water touches the shaft of the piston and can corrode the metal, abrading the O-rings that seal the chamber. Yes if you perfectly flush the reg every time, this is minimal, but this does present a failure mode that isn't present in a sealed diaphram style regulator. Ditto for sand, silt and junk in the water when you dive. not all of us have the privilege of diving in 80 oF water with 100 ft vis

Sherwoods use a flow-by piston with an air-bleed system to seal the regulator, so it does not need "goo" as you put it. The others do need "goo" either Christolube, Tribolube or the older Dow lube if you are not using nitrox.

I know of no training agency that does not teach proper regulator maintenance or tells students you don't need to rinse or soak regulators. Also if the diver is not properly rinsing the regulator, chances are the second stages will start acting up before the first. Corrosion on the piston shaft and spring is rare unless the regulator was used in salt water and put away wet. Unless left for years it is not going to affect performance. Water may wash away some of the lube but it would not abrade the o-ring. BTW, the Scubapro MK-25 has two o-rings at the mushroom end of the piston anyway.

As far as being a failure point, the DIR folks seem to have no problem with piston regulators, piston regulators are commonly used as rentals, and many divers prefer piston regulators on stage bottles because they tolerate floods better. Scubapro and others have been selling piston regulators since the 1960s if there was a fundamental defect in the design it would have showed up by now. The diaphragm on diaphragm regulators is a huge failure point if it get punctured or torn. However, the odds of that happening during a normal dive is very low.

I have been diving since 1992 and besides Florida I also dived in the Northeast so I have experience with silt, sand, cold water, and poor visibility.

 

[JohnN]

Sherwoods use a flow-by piston with an air-bleed system to seal the regulator, so it does not need "goo" as you put it. The others do need "goo" either Christolube, Tribolube or the older Dow lube if you are not using nitrox.

I know of no training agency that does not teach proper regulator maintenance or tells students you don't need to rinse or soak regulators. Also if the diver is not properly rinsing the regulator, chances are the second stages will start acting up before the first. Corrosion on the piston shaft and spring is rare unless the regulator was used in salt water and put away wet. Unless left for years it is not going to affect performance. Water may wash away some of the lube but it would not abrade the o-ring. BTW, the Scubapro MK-25 has two o-rings at the mushroom end of the piston anyway.

As far as being a failure point, the DIR folks seem to have no problem with piston regulators, piston regulators are commonly used as rentals, and many divers prefer piston regulators on stage bottles because they tolerate floods better. Scubapro and others have been selling piston regulators since the 1960s if there was a fundamental defect in the design it would have showed up by now. The diaphragm on diaphragm regulators is a huge failure point if it get punctured or torn. However, the odds of that happening during a normal dive is very low.

I have been diving since 1992 and besides Florida I also dived in the Northeast so I have experience with silt, sand, cold water, and poor visibility.

OK in your experience. Which style (Piston vs sealed diaphram) first stage typically needs less maintenance?

 

[ZzzKing]

I have read some of the data on the Antarctica testing. One point that was brought out is that minor changes in regulator design can affect cold water performance. For example, a newer model of the same regulator with a compact second stage could perform worse in cold water than the older model with a larger second stage. So you cannot blindly follow the recommendations of the Navy unless you are sure the regulator is the same.

Yes, it was mentioned that the Mares reg didn't perform the same as its precursor. In fact, it performed the worst of any in the evaluation. Additional investigation is definitely called for. The xtreme performed well. That's why I linked the article. It was mentioned earlier by another poster.

 

[Tigershark007]

I think I may go with the ScubaPro MK17/A700, due to the fact Casey from Beaver Divers can get a great deal for one. What I figure after looking at how much parts cost for the regulators listed above, that in the end and how much it would cost to service an atomic every 2 years, and the according to scubapro website it has 2 years/dives on regulators. I don't think I would have more then 100 dives in a year. What do you guys think? Is this a safe assumption or am I missing something?

 

[stuartv]

Just FYI, the Tusa R-700 1st stage is IDENTICAL to the SP MK17 and, generally, quite a bit less expensive (around $100 cheaper?).

 

[ams511]

Just FYI, the Tusa R-700 1st stage is IDENTICAL to the SP MK17 and, generally, quite a bit less expensive (around $100 cheaper?).

Also the Subgear line is made and serviced by Scubapro (you can ask Casey) and is cheaper also. However, I think the A700 is a better second stage than what Subgear offers.

---------- Post added August 12th, 2015 at 12:18 PM ----------

OK in your experience. Which style (Piston vs sealed diaphram) first stage typically needs less maintenance?

What do you mean by maintenance? In my experience the rinsing soaking is the same because you still need to soak the second stages because water does get into the internals. If you are talking time between overhauls that depends on the manufacturer and the parts in the kit. BTW, there are other attributes of performance to look at, such as air flow and IP stability. A MK-25 flows more air and is more stable than a MK-17. There was a thread a few years back discussing the IP swing of a MK-17 between a full and empty tank, you can take a look at it if you are interested. You forget the unsealed diaphragm which are far more numerous than the sealed versions. These have been dived safely for years too.

---------- Post added August 12th, 2015 at 12:34 PM ----------

Yes, it was mentioned that the Mares reg didn't perform the same as its precursor. In fact, it performed the worst of any in the evaluation. Additional investigation is definitely called for. The xtreme performed well. That's why I linked the article. It was mentioned earlier by another poster.

The article I read was an older PDF from some symposium way back when. The article said they were using Sherwood Maximus regulators with the heat sink from the Blizzard model, while using a reduced IP. I watched a documentary on Antarctic diving on YouTube and it appeared that is what they were using. Poseidon makes good regulators but I am a bit leery of them. They have a reputation of being finicky to service which may be undeserved. However, they did leave the U.S. market for a while so it makes me wonder about long-term parts availability. I was sort of burned on some Beuchat regulators that became serviceable once Beuchat left the U.S.