AL Mikron 1st Stage Question

[drkcurrent]

Hey All,

Just got a new AL Mikron Regulator package for the holidays and I have a question about the first stage.

What is this metal cover on the yoke? Is this the ACD?

 

[Open Ocean Diver]

The one I have the ACD shutter valve is smooth on top. Have you tried to put it on a tank?

 

[Zef]

That is the current version of the ACD Shutter valve. You can see it in the following video at time 5m33s:


Earlier versions of the shutter valve had a smooth face.

-Z

 

[rsingler]

The ACD quietly acquired that ridge as a result of three cases of gas shutoff DURING a dive. Aqualung never admitted a design flaw, but posted an advisory about shutter valve torque.
What apparently happened is that a loose shutter valve smooth face occluded a 6mm DIN insert in a tank valve. The new ridge now prevents total face contact with the insert, allowing continued gas flow even if the shutter valve loosens.

See this thread:

Aqualung Legend LX First Stage Failure at depth

My first stage failed at about 100-110 feet salt water. The regulator (Aqualung Legend) had about 50 dives (slightly less than a year) from factory new. I spearfish so after the initial descent my dive buddy and I split up-I was solo with a first stage failure. I had about 1500 psi left in my...

scubaboard.com

 

[lexvil]

Overall not a bad concept, like Rob said while they never admitted there was an issue they did implement a fix. This is one of the most often seen regulators in the warm water dive destinations I’ve been to and it’s better now.

 

[buddhasummer]

The ACD quietly acquired that ridge as a result of three cases of gas shutoff DURING a dive. Aqualung never admitted a design flaw, but posted an advisory about shutter valve torque.
What apparently happened is that a loose shutter valve smooth face occluded a 6mm DIN insert in a tank valve. The new ridge now prevents total face contact with the insert, allowing continued gas flow even if the shutter valve loosens.

See this thread:

Aqualung Legend LX First Stage Failure at depth

My first stage failed at about 100-110 feet salt water. The regulator (Aqualung Legend) had about 50 dives (slightly less than a year) from factory new. I spearfish so after the initial descent my dive buddy and I split up-I was solo with a first stage failure. I had about 1500 psi left in my...

scubaboard.com

They never updated diagram. I just bought (a steal) a NOS early legend with the smooth ACD shutter valve, I'll order a ridged one, it'll make me feel better. Thanks for the info.

 

[buddhasummer]

Sorry to kinda highjack, how do you undo the ACD shutter valve? Is there a hex on the underside? I've not disassembled yet and don't have manual.

Also SCT sell this tool, is it necessary?

ACD Tool Set for Aqualung First Stages

This handy tool is used to assist the assembly and dis-assembly of the ACD (Automatic Closure Device) system featured in Aqualung yoke regulators. With this tool, there is no longer any need to swap over between the dust cap and tank valve during service of the ACD. Just simply place the socket...

scuba-clinic-tools.com

Cheers.

 

[Zef]

Sorry to kinda highjack, how do you undo the ACD shutter valve? Is there a hex on the underside? I've not disassembled yet and don't have manual.

Also SCT sell this tool, is it necessary?

ACD Tool Set for Aqualung First Stages

This handy tool is used to assist the assembly and dis-assembly of the ACD (Automatic Closure Device) system featured in Aqualung yoke regulators. With this tool, there is no longer any need to swap over between the dust cap and tank valve during service of the ACD. Just simply place the socket...

scuba-clinic-tools.com

Cheers.

I will send you the service manual for the Core via WhatsApp. If yor 1st stage is FIN then you need a DIN to yoke adapter. The manual has full details for both yoke and DIN

-Z

 

[buddhasummer]

I will send you the service manual for the Core via WhatsApp. If yor 1st stage is FIN then you need a DIN to yoke adapter. The manual has full details for both yoke and DIN

-Z

Thank you sir.

It's this one, yoke.

 

[Zef]

Realized I didn't have the file on my phone so pulled out the laptop and decided to post the file here in case others have a use for it.

I have not been able to locate a service manual for the ACD version of the Legend, but the directions for disassembly/assembly of the ACD mechanism should be the same.

Happy new year!

-Z