eddy testing

[macheezmo37]

Can anyone give me the law on eddy testing an aluminum cylinder.
I am told all aluminum cylinders over 10 yrs old need anual eddy testing and i can not find any dot or any laws saying that for sure, Lds making money again

 

[GrumpyOldGuy]

Some of the cylinders made prior to 1988 used an alloy T6351 that tends to crack under a sustained load (SLC) like a stored bottle of high pressure air. A few failed catastrophically causing significant damage to shops and fill attendants. Most failed with less excitement (but any failure at high pressure is pee-in-you-pants scary).

The Visual Eddy is done at the time of Hydro (every 5 years, not annual) and used to spot the cracks before they fail. I do believe it is a requirements for tanks with the 6351 alloy (Luxfer / Kiddie / USD) made before 1988 from DOT but not 100% certain.

In any case the LDS has the right to refuse to fill if they want for just about any reason. They are the ones most likely to suffer damage from a failure.

 

[znolan]

Some of the cylinders made prior to 1988 used an alloy T6351 that tends to crack under a sustained load (SLC) like a stored bottle of high pressure air. A few failed catastrophically causing significant damage to shops and fill attendants. Most failed with less excitement (but any failure at high pressure is pee-in-you-pants scary).

The Visual Eddy is done at the time of Hydro (every 5 years, not annual) and used to spot the cracks before they fail. I do believe it is a requirements for tanks with the 6351 alloy (Luxfer / Kiddie / USD) made before 1988 from DOT but not 100% certain.

In any case the LDS has the right to refuse to fill if they want for just about any reason. They are the ones most likely to suffer damage from a failure.

This is my understanding as well. There was a free tank program for a couple of years offered by these mfgs, luxfer being the leader, I believe. These days there are perhaps a few left, but IMHO it is certainly foolish to fill one even if it has passed hydro/vip, etc. I believe that the eddie current has to be calibrated to the correct alloy in order to work properly. Even if I use it, I always use the standard vip procedures, too. ...corrections welcome
Oh ya, topic... the dive industry is a self policing industry as far as I know and the LDS can use methods accepted as industry standards for their vips.

 

[akdeepdiver]

What you are looking for is 49 CFR 180.205 (F)(4) and Appendix C to 49CFR Part 180. All cylinders made of 6351-T6 Aluminum alloy are required to have a Eddy Current test performed at time of hydro. Upon passing, they will be stamped with a "VE" after the date. The annual requirement is a dive shop requirement. The DOT only requires it every 5 years.

 

[rjack321]

Can anyone give me the law on eddy testing an aluminum cylinder.
I am told all aluminum cylinders over 10 yrs old need anual eddy testing and i can not find any dot or any laws saying that for sure, Lds making money again

Its their fill station, as long as they are in compliance with DOT regs they can make up whatever additional rules they want. You are unlikely to get your fills without their required eddy tests by merely waving the CFRs in their face.

 

[akdeepdiver]

Its their fill station, as long as they are in compliance with DOT regs they can make up whatever additional rules they want. You are unlikely to get your fills without their required eddy tests by merely waving the CFRs in their face.

I agree. Its like a restaurant saying that they reserve the right to refuse service. So does a LDS, since they are a private industry. That being said, the OP asked where the reference was for Eddy Current so I provided it.

 

[redacted]

Can anyone give me the law on eddy testing an aluminum cylinder.
I am told all aluminum cylinders over 10 yrs old need anual eddy testing and i can not find any dot or any laws saying that for sure, Lds making money again

Its their fill station, as long as they are in compliance with DOT regs they can make up whatever additional rules they want. You are unlikely to get your fills without their required eddy tests by merely waving the CFRs in their face.

I have to wonder whether the shop told the OP that the VE was their requirement or was it the requirement of some other authority that the shop follows. Is this a shop just taking safety measures to protect its staff or is this a shop that has found a way to increase profits with a little deception?

 

[Scared Silly]

What you are looking for is 49 CFR 180.205 (F)(4) and Appendix C to 49CFR Part 180. All cylinders made of 6351-T6 Aluminum alloy are required to have a Eddy Current test performed at time of hydro. Upon passing, they will be stamped with a "VE" after the date. The annual requirement is a dive shop requirement. The DOT only requires it every 5 years.

Here is the actual CFR:

Hazardous Materials: Aluminum Cylinders Manufactured of Aluminum Alloy 6351-T6 Used in SCUBA, SCBA, and Oxygen Services--Revised Requalification and Use Criteria | Federal Register Environmental Documents | USEPA

 

[rjack321]

I have to wonder whether the shop told the OP that the VE was their requirement or was it the requirement of some other authority that the shop follows. Is this a shop just taking safety measures to protect its staff or is this a shop that has found a way to increase profits with a little deception?

Unless the shop is also a hydrostatic requalifier they can't actually stamp the tank with anything.

I am guessing this is just a CYA tactic on the shop's part. And they make eddy currents a required part of their VIPs for tank >10yrs old. Does makes me wonder if they are requiring them for steel tanks...

 

[Scared Silly]

The "problem" is that before DOT stepped in and made eddy current tests mandatory at the time of requalification (aka hydro) for AL6351 cylinders many dive shops invested in eddy current testing equipment which was used as part of the annual scuba industry visual inspection program. As such, the equipment at the dive shops is not really needed. However, as said the shops can make up their own rules. So if they say they want an eddy current test annually for filling then that is their rules.