Transforming eCCR into hCCR

[Gone for diving]

What pressure do you run a open first first stage with a needle valve?
Like 120 - 150 psi?

 

[Dsix36]

What pressure do you run a open first first stage with a needle valve?
Like 120 - 150 psi?

Whatever the manufacturer recommends. IIRC my DR's set to 145psi

 

[Gone for diving]

Going from 0.2 LPM up to 1.2 LPM (who works harder than that diving?) is about 3/4 to 7/8ths of a turn.

I was reading this and figured if you don't want it as sensitive then lowering the pressure would help...

 

[mr_v]

What pressure do you run a open first first stage with a needle valve?
Like 120 - 150 psi?

145 psi is typically the standard. However, you can get a stronger spring. Fathom has an option for 205psi.

 

[Gone for diving]

145 psi is typically the standard. However, you can get a stronger spring. Fathom has an option for 205psi.

But I assume that's a plugged first stage.
So you can go deeper.
Not a normal open first stage.

 

[Dsix36]

I might as well throw another monkey wrench into this discussion. They to figure out the benefits/risks of using a regulator that is overcompensating (like some of the Apeks) while using it unblanked with a needle valve. How will things react at different depths now?

 

[mr_v]

But I assume that's a plugged first stage.
So you can go deeper.
Not a normal open first stage.

Yes, plugged first stage + stronger spring + constant mass flow valve. Basically, mCCR that can go deeper.

If you unplug the first stage, you must close the CMF valve and figure out how to inject O2.

 

[jwd]

I did the same with my JJ and a Subgravity needle valve. Set point at 0.7 (just in case) and the needle valve to maintain the desired PPO2. Haven't blocked the first stages for the time being but generally don't open the needle valve until on the bottom.