Modified "Z" system

[Kevrumbo]

Semantics perhaps, but a quick glance in V2.0 of the Procedures Manual --there is nothing there explicitly stating that the DB has been superseded by the Isofold or that it is in fact "non-standard" as you claim; and the online UTD Store continues to market and sell it (as well as support the old QC6 plug-in "slim-line octopus" 2nd stage regulator).

 

[SanDiegoSidemount]

Semantics perhaps, but a quick glance in V2.0 of the Procedures Manual --there is nothing there explicitly stating that the DB has been superseded by the Isofold or that it is in fact "non-standard" as you claim; and the online UTD Store continues to market and sell it (as well as support the old QC6 plug-in "slim-line octopus" 2nd stage regulator).

Now that we've lost everyone who's not in our UTD Kool-Aid club...

The replacement of DB with isolator has not been explicitly announced, you're right. I get this from conversations around HQ and the omission of this configuration from most of their newer training materials.

The distribution block is still in use, and recommended for the Z in single tank recreational configuration, which is taught in OW and Rec 1/2/3. The slim line reg is still relevant for an LP failure in any DB configuration.

There is still a valve drill published for the doubles + DB configuration. However, this configuration doesn't exist in the Valve Failure procedures in the Student & Diver Procedures book.

 

[Razorista]

...our UTD Kool-Aid club... ...

Since you two seem well informed I have to ask an uninformed question:

How does the isolator manifold work?

To be more precise:
What is 'isolated', where?
What is you procedure on a short-hose freeflow?
And on the long-hose?

 

[SanDiegoSidemount]

How does the isolator manifold work?

To be more precise:
What is 'isolated', where?
What is you procedure on a short-hose freeflow?
And on the long-hose?

The manifold is an LP distribution system that sits between the shoulder blades with a knob at the top that isolates left and right LP systems. Each side has a QC-6 input from one of the cylinders. In a typical configuration, the right side outputs to long hose and BC inflate, and the left side outputs to short hose and drysuit inflate. Closing the isolator gives you two separate LP circuits to work with.

Procedure on either 2nd stage free-flow is to verify both cylinders on, isolate left and right sides, and shut down the side causing free flow while breathing off the good side. If the gas in the shut down cylinder is needed to safely complete the dive, it can be cross-plugged to the QC-6 on the good side.