DGX Gears XTRA first stage service

[SaltyWombat]

Because I have 4 of them sitting in a box after one failed to reopen after a valve drill.

I'm puzzled by that. Here's how the ACD works:



The ACD should not close during a valve drill since you're only shutting down gas, not removing the valve regulator.

This is an interesting problem to think about. I wonder if the reg was not 100% screwed in. Maybe it was screwed in enough to open the ACD and create a seal at the beginning of your dive, but it came loose during a valve drill when the reg was not pressurized. This doesn't seem likely, but it's the only thing that comes to mind right now.

Are you able to reproduce it topside, like in your garage?

 

[crofrog]

I'm puzzled by that. Here's how the ACD works:



The ACD should not close during a valve drill since you're only shutting down gas, not removing the valve regulator.

This is an interesting problem to think about. I wonder if the reg was not 100% screwed in. Maybe it was screwed in enough to open the ACD and create a seal at the beginning of your dive, but it came loose during a valve drill when the reg was not pressurized. This doesn't seem likely, but it's the only thing that comes to mind right now.

Are you able to reproduce it topside, like in your garage?

I'm very well aware of how the ACD works, and I'm glad they have an option not to have it on the regulator now. It is a known issue regarding potentially out-of-spec 300-bar din manifolds and early XTRA regulators. DGX offered to take care me a few years ago, but I never got around to sending the regs back to them.

Regulators back off sometimes when being pressurized / depressureized I'm sure that is what happened during the valve drill. The issue is the failure mode it made impossible to fix underwater (and hard to fix on land) because there was no way to remove the pressure caught between the valve and the ACD.

On the valves that had issues, it was actually possible to create a noticable pressure drop on the HP side when purging them.