Sealed vs unsealed

[pepperbelly]

Is there a reason to not use a sealed first stage vs an unsealed for warm water diving?
I understand a sealed diaphram is mostly for cold water or contaminated water diving and not needed for warm water, but is an unsealed piston better?
I am just trying to understand why a sealed regulator is only recommended for cold water and not for all diving.

 

[lexvil]

You are unlikely to ever see a difference, here is the best deal I've seen in a while
For Sale - Mk25evo/s620ti

If I wasn't so fat on Regs I would be all over it?

 

[pepperbelly]

That is a deal.

 

[guruboy]

Is there a reason to not use a sealed first stage vs an unsealed for warm water diving?
I understand a sealed diaphram is mostly for cold water or contaminated water diving and not needed for warm water, but is an unsealed piston better?
I am just trying to understand why a sealed regulator is only recommended for cold water and not for all diving.

There are a lot of threads about this. If you have trouble finding information when searching, it helps to search by thread and title only.

But one of the main reasons is to help reduce chances of freezing, since no water touches the internal parts.

 

[rhwestfall]

Not having to worry about getting salt out of an ambient chamber is also a plus!

 

[Lorenzoid]

Is there a reason to not use a sealed first stage vs an unsealed for warm water diving?
I understand a sealed diaphram is mostly for cold water or contaminated water diving and not needed for warm water, but is an unsealed piston better?
I am just trying to understand why a sealed regulator is only recommended for cold water and not for all diving.

I don't believe I have heard that "a sealed regulator is only recommended for cold water and not for all diving." As far as I know, the seal on a diaphragm reg doesn't have any effect on its performance, and the reg works just as well in all conditions. If I am not mistaken, HOG regs, for example, are currently sold only with a seal. They used to offer them in both regular (without seal) and "cold water" (with seal) flavors, but no longer do. I have an early version without the seal as well as the later version with the seal. The only difference I can perceive is ... the seal.

Sealed versus unsealed piston regs could be a different story entirely. I don't know. I believe sealing a piston reg is more involved, and therefore adds cost, than sealing a diaphragm reg.

 

[diversteve]

My regs (Atomics) have never seen cold water yet I pay $40 to have them sealed. I shore dive and the sand is often in suspension near the beach - I don't want the grit in there near a moving part. It makes zero difference in performance from what I've been told.

 

[Ghetto Diver]

Go Sherwood
No worries no more.

 

[scubadada]

You are unlikely to ever see a difference, here is the best deal I've seen in a while
For Sale - Mk25evo/s620ti

If I wasn't so fat on Regs I would be all over it?

Wow, same with me, I need another reg like I need a hole in the head, but I was tempted

 

[pepperbelly]

I have asked about a lot of regs here, and when I ask about one that is sealed someone comes along and says I don't need a sealed first stage.
I was wondering why I would be discouraged from buying one.