Poseidon Regs and DIR

[caboman]

Just throwing this out there as a disscusion point.
I've been told DIR frown on the use of Poseidon regs as apperently the will not function properly with a tank pressure lower than 200psi...
Yet they are known world wide as one of the best ever deep diving regs, that provide a ton of gas at depth.
And from my point of view... if your down to 200psi in your tank you have much bigger issues...
Your thoughts?

 

[dsteding]

My understanding is that they fail closed rather than open, and I believe there are issues with taking them apart underwater. But I could be mistaken on that second point.

Never heard of the 200 psi bit, as that has never been thrown out as a reason for picking a reg (it sorta runs against DIR gas planning as well).

 

[caboman]

Thats what I thought as well on the 200psi bit... just didnt make much sense with DIR protocals...

Any other documentation or thoughts out there on this?

 

[jeckyll]

Thats what I thought as well on the 200psi bit... just didnt make much sense with DIR protocals...

Any other documentation or thoughts out there on this?

Use the Search.

Been discussed many times. Apparently only an (?) older design failed open.

 

[nadwidny]

Just throwing this out there as a disscusion point.
I've been told DIR frown on the use of Poseidon regs as apperently the will not function properly with a tank pressure lower than 200psi...

They require a certain amount of pressure to keep everything closed up. When they get below a certain IP they tend to dump all the remaining gas. Wish I had been told that when I bought my Jetstream. Would've made an interesting experience much less interesting.

Yet they are known world wide as one of the best ever deep diving regs, that provide a ton of gas at depth.

So do a lot of regs nowadays. POSeidon's are relying on a 20 year old reputation that was built on deep air. There are regs now that are just as good.

And from my point of view... if your down to 200psi in your tank you have much bigger issues...

Yup but sometimes sith happens and I personally would like to have that last 200 psi available for use rather than dumped in a big cloud of bubbles.

The biggest issue with POSeidon 2nds is that the Jetstream is of an upstream design which in it's simplest version would fail closed. POSeidon gets around that by putting in an OPV in the hose (can you say "Another failure point? Good, I knew you could). They also cannot be taken apart underwater, another big no-no for DIR fans.

 

[nadwidny]

Now having said all that, if I needed a reg where I absolutely, positively could not afford a frozen reg, I would go with a Jetstream 2nd every time.

 

[rjack321]

Poseidens also have a reputation as being incredibly finicky to service (compared to modern diaphram and piston regs). That kinda runs against the "simple is better" DIR approach.

Gas delivery at depth is basically a moot point since if you use helium based gasses even the cheapest of regs is still end up being fairly good performers.

 

[David Watson]

My understanding is that they fail closed rather than open, and I believe there are issues with taking them apart underwater. But I could be mistaken on that second point.

Never heard of the 200 psi bit, as that has never been thrown out as a reason for picking a reg (it sorta runs against DIR gas planning as well).

As far as I understand, DIR gas planning actually does use the last 500 PSI, but only if you´re sharing air which is when you would need a functioning reg the most. Correct me if I´m wrong, but a reg failing with 200 psi seems to be a major problem for DIR´s reason for saving the last 500.

David

 

[JeffG]

Correct me if I´m wrong, but a reg failing with 200 psi seems to be a major problem for DIR gas planning and ratio deco.

David

Why would a reg that stopped delivering gas at 200 psi have anything to do with ratio deco? and why couldn't a diver compensate for this phenomenon in the gas plan?

 

[David Watson]

Why would a reg that stopped delivering gas at 200 psi have anything to do with ratio deco? and why couldn't a diver compensate for this phenomenon in the gas plan?

it doesn´t, i mispoke and changed it. Why would you want to have a limit on breathing your gas? If you are in an emergency situation and breathing down your tanks, and the last 500 psi doesn´t read all that accurately from your preassure gauge anyway, why would you want to have to worry about your reg malfunctioning at apx. 200 PSI? That seems like it would go against everything that DIR stands for. I can think of many emergency situations where every last PSI counts.

David