80'S AL Tank Inspections - Eddy Current?

[oxyhacker]

- If by "Vi" you mean visual inspection, then it is not the same thing as a VIP at all. "Visual inspection" is a very general term that must be used in a specific context to have any meaning, but VIP is specific to the annual tank inspection done by dive shops. That is to say, a VIP may be a visual inspection, but a visual inspection is not necessarily a VIP.

- the DOT does not set any guidelines for the annual inspections done by dive shops.

- it is perfectly legal for a retester to disable a tank by drilling a hole in it rather than marking it. See 49CFR180.205 or thereabouts, "Alternatively, at the direction of the
owner, the requalifier may render the cylinder incapable of holding pressure." This is something, obviously, best negotiated with the tester beforehand.

OK,
Well lets break it down. A Vi/VIP is the same thing. DOT does set some guide lines for Dive Shops. DOT states that this is ok and this is not for pass or fail. A dive shop can say this tanks fails but I would hope if they take it to another dive shop they will say the same thing. It was stated earlier about vintage tanks. If you send it in for hydro-test and it fails they must stamp out the DOT markings not just drill a one in the bottom as was stated by anothe member. If you want to keep it vintage with the markings keep it at home and don't send it in for test.

 

[drywaterdiv]

Reference tanks that need eddy current test. All tank made prior to 1990 need the test. A new law the DOT made went into effect Jan.1, 2007.

As for Nemrod comments on personal tanks not needing hydro, DOT CFR49 180-205 (c) states Each cylinder bearing a DOT specifiaton markings must be requalified. You can do what you want with anything till you get caught then you get in trouble. Don't tell the public something that isn't true. You my chose not too but it doesn't make it right.

As for DA comment - a visual inspection is done prior to a hydro-test and after. There is no sense of testing a tank first to fail it later. Why take the time to fill it with water, test it then drain it and dry it if it is going to fail a visual.

As for the eddy current test the new law says for condemnation criteria-A cylinder must be condemned if the eddy current examination combined with visual examination reveals any crak in the neck or shoulder of 2 threads lengths or more.

I know this puts a dive shop in the middle of a big mess. Most guidelines used for VIP's come from the CGA. Now with this new law on eddy testing does a shop have to render the cylinder unserviceable if it fails??? What a mess is all I have to say.

 

[in_cavediver]

Reference tanks that need eddy current test. All tank made prior to 1990 need the test. A new law the DOT made went into effect Jan.1, 2007.

False. DOT regs say 6351 alloy tanks need the eddy current test and must be stamped VE at requalification. 6061 is not mentioned at all

As for Nemrod comments on personal tanks not needing hydro, DOT CFR49 180-205 (c) states Each cylinder bearing a DOT specifiaton markings must be requalified. You can do what you want with anything till you get caught then you get in trouble. Don't tell the public something that isn't true. You my chose not too but it doesn't make it right.

This is again up for debate. DOT's authority come in governing commerce and transportation. An arguement can be made for personal tanks not filled by a commercial entity and used for purely personal endevours. This is purely academic since except in very rare cases, your tanks will touch a commercial entity. That, and it just makes sense to test your tanks.

As for DA comment - a visual inspection is done prior to a hydro-test and after. There is no sense of testing a tank first to fail it later. Why take the time to fill it with water, test it then drain it and dry it if it is going to fail a visual.

As DA said, the official inspection is done post hydro. A non-official test is done pre hydro for the reasons both of you mention but it is not the official inspection unless it fails and the hydro test is not preformed.

As for the eddy current test the new law says for condemnation criteria-A cylinder must be condemned if the eddy current examination combined with visual examination reveals any crak in the neck or shoulder of 2 threads lengths or more.

For 6351 alloy tanks when taken to a DOT licensed requalification station only. As stated above 6061 alloy does not require eddy current.

I know this puts a dive shop in the middle of a big mess. Most guidelines used for VIP's come from the CGA. Now with this new law on eddy testing does a shop have to render the cylinder unserviceable if it fails??? What a mess is all I have to say.

Bunk. Most dive shops are not licensed by the DOT for cylinder requalification. The new law/rules specifically governs licensed requalification stations ONLY. Dive shops are not required to do annual visuals at all let alone eddy current testing.

Please stop spreading misinformation. Dive shops do not have legal standing with regard to qualification and permanent condemnation of pressure vessels unless they are licensed by the DOT as a requalification provider (hydro shop). Period.

If an unlicensed dive shop wishes to permanently condemn a tank without the owners consent, they must take it to a DOT licensed requalification center (hydro shop) and the DOT licensee can make that determination and have legal standing to make a tank unusable.

 

[drywaterdiv]

Well I went to our local hydro company and had them make me a copy of the laws and what tanks have to be tested. They are to test tanks made before 1990. And for VI and DOT tanks they made me a copy of the law. That is all I was quoting is what was printed. Enough said

 

[Nemrod]

drywaterdiv, I am sorry that your wrong but you should not spread false info to the public because your interpretation of the law is incorrect. So, not enough said, your wrong. Private use is not included in DOT regulations governing commerce and transportation. I don't have to hydro anything, I can carry my non hydroed tanks on my boat and fill them with my compressor till hell freezes over and there is nothing the DOT can do about it under the current laws.

N

 

[DA Aquamaster]

Well I went to our local hydro company and had them make me a copy of the laws and what tanks have to be tested. They are to test tanks made before 1990. And for VI and DOT tanks they made me a copy of the law. That is all I was quoting is what was printed. Enough said

The way I read the CFR in question, the eddy current test requirements apply only to 6351-T6 tanks (and excludes those used in CO2 applications which are by definition much lower pressure) and the 1990 date is mentioned only in the context of this being the date after which no more 6351-T6 tanks were produced.

This is also supported by the fact that several times during the Federal Register discussion of public comments and the rationale for the final rule, the phrase "DOT cylinders manufactured of 6351-T6 alloy aluminum" is mentioned several times in the context of what tanks are affected by the new regulations.

If you disagree, feel free to post a pdf of the copies of the regs you have in your posession. Otherwise, drop the issue as no one benefits from the dissemination of second hand false information.

The issue is already going to be confusing enough as the average tank monkey and local dive shop owners are probably not going to bother checking an individual tank against the cut off dates for 6351-T6 aluminum in that type of tank, are not going to be concerned that Catalina never used 6351-T6 aluminum in their tanks and are in essence going to insist on eddy current testing any tank older than 1990 - which also coincidentally has the effect of increasing their cash flow for the needless eddy current inspection of all of the 6061-T6 tanks produced prior to 1990.

I'd prefer to provide divers with accurate information so that they at least know the socre an perhaps can "educate" ignorant dive shop owners when they encounter them and/or take their business elsewhere if the LDS owner is not ammenable to being educated.

 

[Jim Lapenta]

Whatever happened here may be happening lots of places. The new law that went into effect on 1/1/2007 has made it so that the facility we use for hydro will not even test tanks made before 1990. Whether they pass an eddy or not. Their reasoning is even if it passes hydro today 3 months from now it could fail. Sounds strange but that is what their policy is now and another facility we use when they are tied up is doing the same. No aluminum tanks before 1990 are going to be accepted for hydro. Glad all of mine are steel except for the al pony which is only two years old and my 40 stage which is only two.

 

[Leadking]

Whatever happened here may be happening lots of places. The new law that went into effect on 1/1/2007 has made it so that the facility we use for hydro will not even test tanks made before 1990. Whether they pass an eddy or not. Their reasoning is even if it passes hydro today 3 months from now it could fail. Sounds strange but that is what their policy is now and another facility we use when they are tied up is doing the same. No aluminum tanks before 1990 are going to be accepted for hydro. Glad all of mine are steel except for the al pony which is only two years old and my 40 stage which is only two.

Sounds like a real "professional" operation!!!

I'd look elsewhere.

 

[DA Aquamaster]

The eddy current test protocols have been effective in identifying 6351 tanks with cracks before they can propogate to the point of failure and they pose no additional risk of failure. In fact, I can find no documented case of a properly inspected 6351 tank catatrophically failing due to SLC since eddy current testing came into use.

However despite this, the reality is that some dive shops are electing not to fill older tanks due to concerns about sustained load cracks in 6351 tanks. That is their perogative as they are the people assuming the risk and the liability. It remains to be seen if the DOT final rules on the issue and the DOT additionally declining to impose a 40 year lifespan on 6351 tanks will change that situation to any great extent.

The same thing could be said about a hydro test facility that elects not to test tanks older than 1990. There is no law that compells them to do so and like any other business, they can refuse service to anyone - as long as they do not do so in a discriminatory manner.

That said, I agree that I'd find another test facility...but then I tend to come down pretty hard on the customer service and consumer advocacy side of the fence.

 

[DA Aquamaster]

I managed to locate my list of the dates and manufacturers copied from a DOT Safety Alert Bulletin. These are the scuba tanks considered by the DOT to be most likely to be made from 6351-T6 alloy. If there is any doubt, it's obviously better to err on the side of caution and assume it is 6351-T6 alloy.

1. All DOT-3AL tanks manufactured under one of the following exemptions or special permits: 6498, 7042, 8107, 8364, 8422

2. All composite cylinders manufactured under one of the following exemptions: 7235, 8023, 8115

3. All Walter Kidde DOT-3AL scuba tanks.

4. All Cliff Impact DOT-3AL scuba tanks made before July 1990.

5. All Luxfer 80.8 cu. ft. scuba tanks (S80.8) made before May 1987.

6. All Luxfer 72 and 100 cu. ft. scuba tanks (S72, S100) made before August 1987.

7. All Luxfer 80 cu. ft. scuba tanks (S80) made before January 1988.

8. All Luxfer 50 and 92 cu. ft. scuba tanks (S50, S92) made before April 1988.

9. All Luxfer 30 and 63 cu. ft scuba tanks (S30, S63) made before May 1988.

10. All Luxfer 40 cu. ft. scuba tanks (S40) made before June 1988.

11. All other scuba tanks made in the US before February 1990 (except Catalina).

12. All scuba tanks not made in the US.

A hydro tester freind of mine advised me that hydro testers are being advised to test all tanks made prior to 1990. However, that recommendation itself may be inadequate given that Walter Kidde tanks were made at least into 1990 and possibly 1991 (if I remember correctly) Cliff Impact tanks were made of 6351 alloy until July 1990.

On the other had, Luxfer switched to 6061-T6 alloy on some of its tanks as early as May of 1987 and switched S80 production to 6061 in January 1988 so there are 2 years worth of Luxfer AL 80 production that are made from 6061 and would be tested as 6351 tanks under the "test everything made prior to 1990" recommendation.

If I owned a tank in that age range I'd probbaly want to check to see if the test facilty was using the latest Visual plus equipment or was doing a good job of eliminating false positive test results on 6061-T6 tanks with older visual plus equipment.