Backup Regulator Question

[Sharky1948]

My understanding is that DIR recommends a non-balanced first stage for the backup regulator. I am planning a Scubapro MK25/S600 for the primary reg. The only non-balanced regs Scubapro have are warm water, entry level. That seems to be true for Apeks as well.

Questions:
1) Do I understand the DIR position correctly?
2) Does a de-tuned reg meet the requirements, i.e., not free-flowing, etc.

Seems like the photos I see of DIR divers often have the same regs for primary and backup...including one of G. Irvine's equip which appears to be two identical Apeks.

Thanks!

 

[MilitantMedic]

Yes # 2 is correct. i.e. tune a S600 all the way down. When you put it in your mouth you can turn it up.

 

[Sharky1948]

Yes # 2 is correct. i.e. tune a S600 all the way down. When you put it in your mouth you can turn it up.

Thanks! That was easy!

 

[RobbieTheHun]

I use two Mark 25 first stages with an S600 as my primary and a R390 as my backup. I have had no free flow problems even with trimix.

RTH

PS: I just made the switch from Atomic M1's

 

[amascuba]

My understanding is that DIR recommends a non-balanced first stage for the backup regulator. I am planning a Scubapro MK25/S600 for the primary reg. The only non-balanced regs Scubapro have are warm water, entry level. That seems to be true for Apeks as well.

Questions:
1) Do I understand the DIR position correctly?
2) Does a de-tuned reg meet the requirements, i.e., not free-flowing, etc.

Seems like the photos I see of DIR divers often have the same regs for primary and backup...including one of G. Irvine's equip which appears to be two identical Apeks.

Thanks!

Actually a non-balanced second stage is what they recommend. Allot of people use the same second stages for the primary and backup, but de-tune the backup so that it is less likely to free-flow.

I use Salvo SR1 First stages and Scubapro G250HP's for my second stages.

 

[GDI]

What Apeks model regs are you referring to that are warm water entry level?

 

[serrada]

What Apeks model regs are you referring to that are warm water entry level?

There the ...20's

 

[GDI]

The AT 20 and the XTX20, I see what you are saying. Both these have a balanced diaphragm first stage and you are talking about non-balanced

Yes detuning a reg helps it deal with colder water temp and performance

 

[serrada]

Sorry, I got my post mixed up. It's my
ADD. The TX20, ATX20 and XTX20 are not detuned 2nd stage regulators. They don't have the heat sinks that the others in their families have that's why that are considered for warm water.

The Scubapro R series are unbalanced 2nd stages of the type they recommend for DIR.
Apeks doesn't make a standard detuned unbalanced regulator.

What people do with the balanced regulator with the adjustment knob (of the variety of the S600, G250, TX/ATX/XTX- 50/100/200) is once in the water they turn the adjustment knob in and switch the regulator from pre-dive to dive.

 

[Chris Sawallich]

What people do with the balanced regulator with the adjustment knob (of the variety of the S600, G250, TX/ATX/XTX- 50/100/200) is once in the water they turn the adjustment knob in and switch the regulator from pre-dive to dive.

If the reg is tuned right, you can just turn the knob back mabye 1/2 a turn and leave the slide in "pre-dive" I dive two ATX50's and two DS4's and have no issues with free-flow from the secondary.