Question Two different part numbers for Atomic main spring?

[Wiznutaggie]

I've found two different part numbers for the Atomic main spring. 21-0574-00 and 21-0570-00. Anybody know if there's a difference between the two?

 

[Couv]

@Wookie will have the definitive answer. :-D

In the meantime, looking at a couple of schematics I see the:
21-0570-00 listed in the ST1 schematic.
The 21-0574-00 is listed on the T2, T1, T1X, B2, Z2, Z1, M1 schematic.

 

[Wiznutaggie]

@Wookie will have the definitive answer. :-D

In the meantime, looking at a couple of schematics I see the:
21-0570-00 listed in the ST1 schematic.
The 21-0574-00 is listed on the T2, T1, T1X, B2, Z2, Z1, M1 schematic.

Yep, the 21-0570-00 also comes up on the T2X schematic. I don't have a T3 schematic, but I'm betting it's on it too? Basically the "newer" model regs as far as I can tell changed to the 21-0570-00, but have found 0 info on if there was any function change or for what reason there was a change.

 

[Wiznutaggie]

Bueller?

 

[Couv]

Bueller?

At home, too sick to do homework-see attachments.

 

[Wiznutaggie]

At home, too sick to do homework-see attachments.

Well that confirms that the spring part number changed starting with t2x and continued. Still wonder if it was only a number change or if something about the spring that changed.

 

[rsingler]

There was a rare failure incidence. The metal was changed and all new springs are etched with an alphanumeric on one end.
It was recommended at a seminar a few years ago that springs below Nxx (where xx is a number) should be replaced. No recall, just an advisory.

 

[Wiznutaggie]

There was a rare failure incidence. The metal was changed and all new springs are etched with an alphanumeric on one end.
It was recommended at a seminar a few years ago that springs below Nxx (where xx is a number) should be replaced. No recall, just an advisory.

Very interesting, thanks! Curious why there wasn't a recall then if there is a incidence of failure and they recommended the springs replaced. It must have been an exceedingly rare incidence and I'd assume there is a large number of them still in use with the old spring. Still, the new spring is relatively cheap, so might as well put it in my next rebuild then.

 

[Wookie]

Sorry, I don’t get alerts.

AFAIK, there were very few spring failures on the older atomic regulators. I have first stage number 37 (BA ????? 037) which failed. My wife has number 145, which also has a spring fail. Both failed by rusting through.

I have owned 20 T1’s and about the same number of M1’s. Those were the only 2 that failed, they were both sealed, both had thousands of dives at failure.

It’s not something I would be overly concerned about unless you are doing hundreds of dives between 3 year overhauls.

 

[dlao]

Sorry for hijacking this post. Recently came across an older Atomic Z1. It's the first time I see a main spring corroded and collapsed. Gonna replace it by the updated spring.