Diaphram vs Piston regs.....

[jefffalcone]

Both are very good,with a slight edge to diaphram in cold water.
most reg are going to be ok down to 45 degree water temp.
Piston has less moving parts,higher flow rates.
Both of my regs are diaphram type.
If you are going to be Diving in cold water i would go with diaphram.
Diaphram regs are sealed in the first stage,pistons are usally not.
Sherwood,atomic and i think genesis are sealed piston types that would be good for cold water diving.
There are alot of choices, so have fun looking and be safe.

Atomic is not a sealed piston. If you want it to be environmentally sealed, you have to pack it with cristo-lube, just like any other piston first stage.

Sherwood uses a unique design that uses a bleeder valve to regulate the pressure. If I understand correctly it regulates pressure by maintaining a constant rate of flow out the bleeder valve, rather than allowing water into the ambient chamber. They have a reputation for being very good in cold water, but I'm not crazy about their second stages.

I don't know anything about genisis. I'm not really sure what a "sealed piston" would be other than the unique Sherwood design, but I'm no expert. Just read Vance Harlow's book, and I don't remember anything about sealed pistons.

 

[Luis H]

Atomic is not a sealed piston. If you want it to be environmentally sealed, you have to pack it with cristo-lube, just like any other piston first stage.

Sherwood uses a unique design that uses a bleeder valve to regulate the pressure. If I understand correctly it regulates pressure by maintaining a constant rate of flow out the bleeder valve, rather than allowing water into the ambient chamber. They have a reputation for being very good in cold water, but I'm not crazy about their second stages.

I don't know anything about genisis. I'm not really sure what a "sealed piston" would be other than the unique Sherwood design, but I'm no expert. Just read Vance Harlow's book, and I don't remember anything about sealed pistons.

Personally, I would call any piston regulator that you seal the ambient water from entering the ambient pressure chamber (but does transmit ambient pressure) a “sealed piston” first stage.

Examples:
• Sherwood dry bleed …it has a constant leak and a check valve on the ambient chamber, any air pressure in excess of ambient pressure bleeds out.
• Atomic lubed packed ambient chamber.
• Old Scubapro lubed packed ambient chambers.
• Genesis shredder type valve in the first stage is kind of a mini primitive second stage that feeds the ambient chamber with ambient pressure air. Neat idea, but IMHO complicated.
• The new Sherwood SR-1 …it looks like it uses an external diaphragm and mechanical push rods to transfer pressure to the piston (similar to some of the new style diaphragm dry chambers).

There may be more out there that I am not familiar with.



I like the simplicity of an old piston regulator (Scubapro Mk-5), but lately my favorite first stage is any of the Royal Aqua Master derivatives…Conshelf, Titan, etc. They are simple reliable diaphragm and I normally use them in a sealed configuration. Parts will be around for a long…long time.

The Mk-17 sounds like the Scubapro equivalent to my favorite first stage. I just hope that its long term reliability comes close to the Conshelf and that Scubapro doesn’t change it just to have something different. At least they should just do like US Divers (Aqua Lung) just change the outside looks, but keep all the same internal parts.

 

[jonkcp]

I asked same question in the past between MK17 & MK25 with G250V. At the end, I selected the MK17. 1st MK17 is a close system; it can minimize the problem of maintenance (salt crystallization). No matter, you dive in cold and warm water. 2nd I selected G250V. It can help solve my dry mouth problem. You would not be wrong to select MK17 with G250V.

 

[danemeyer20]

I asked same question in the past between MK17 & MK25 with G250V. At the end, I selected the MK17. 1st MK17 is a close system; it can minimize the problem of maintenance (salt crystallization). No matter, you dive in cold and warm water. 2nd I selected G250V. It can help solve my dry mouth problem. You would not be wrong to select MK17 with G250V.

that is the exact setup i am going to get. Not sure why Scubapro doesnt sell it as a package in the US. pain in the ass

 

[jonkcp]

In Hong Kong, the local SP standard price page did not have combo for MK17+G250v. It is a marketing. G250V is latest 2nd from SP. But my local SP dealar offered a good package. Enjoy your gear.

 

[danemeyer20]

im getting the mk17/g250v from a dive shop for $450 so i cant complain and hes going to throw in an r295 for my secondary for 70 bucks. All together im getting a sick setup for $550 bucks so im excited. Eventually when i get the money i am going to uprgade the secondary to the g250v as well

 

[GYANNI]

Question from a newbie: what's a good regulator to dive in both cold and warm water without having to buy two?

 

[Cyclops_Diver]

Question from a newbie: what's a good regulator to dive in both cold and warm water without having to buy two?

The MK17/G250V.

Environmentally sealed first stage which helps in ease of cleaning, frigid water performance, deep dives...

Second stage metal air barrel helps alleviate dry mouth, it's adjustable design helps tune to absolutly beautiful performance.

That's just a quick and dirty in my opinion. I dive the MK17/G250V. Would dive that combo in almost any situation. I say "almost" because nobody can predict every dive situation, but so far this combo is what I want to be breathing on.

 

[Packhorse]

It depends on how you define cold. I recon 12 deg C is cold but as far as regs go its not.
Anyway a good cold water reg should be a good all round reg. Anything with a seal 1st stage and a metal air barreled 2nd should be OK. EG MK17 & G250V or just about any Apeks.

 

[steindawg]

im getting the mk17/g250v from a dive shop for $450 so i cant complain and hes going to throw in an r295 for my secondary for 70 bucks. All together im getting a sick setup for $550 bucks so im excited. Eventually when i get the money i am going to uprgade the secondary to the g250v as well

Is this an average price for this setup? LDS quoted me 575 for the mk17/g250v this afternoon.