does anyone know where I can find documentation showing that old Norris Lp72 steel tanks are galvanized (or not).
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Galvanized LP72 documentation
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runsongas
Contributor
I just happen to look at this thread and I saw my name…
I don’t know of any documentation showing that Norris tanks were galvanized. I know all of mine are galvanized, because it is obviously a hot dip galvanized finish. But there were some steel 72 that had a factory paint finish. Some of them were galvanized under the paint, but some were not.
I own around 10 Norris (and about 20 PST) cylinders, and everyone of them is hot dipped galvanized. I do not use any steel cylinder that is not galvanized.
A couple of my cylinders have black factory paint on top of the galvanizing, but I can see the galvanizing finish under the paint. I cut a small rectangle of paint to provide a good spot for stamping the new hydro dates and the galvanize finish is obvious.
If you have a galvanize cylinder with no paint, it should be obvious.
If you have a painted cylinder, it may or it may not be galvanized. If the paint is truly intact, it may be very difficult to tell if there is galvanizing under the paint. But, if the paint has any cuts, it is probably easy to tell if it is galvanized under the paint. If it is not galvanized, you will probably see some orange rust spots.
Norris was sold extensively by Healthways (and a few others). Healthways sold galvanized tanks and in a number of the old catalogs (I just checked 68, 69, and 70) they also had what they called safety yellow tanks. The description of their yellow cylinders in the catalog doesn’t seem to have a galvanizing finish under the paint.
I hope this helps.
I don’t know of any documentation showing that Norris tanks were galvanized. I know all of mine are galvanized, because it is obviously a hot dip galvanized finish. But there were some steel 72 that had a factory paint finish. Some of them were galvanized under the paint, but some were not.
I own around 10 Norris (and about 20 PST) cylinders, and everyone of them is hot dipped galvanized. I do not use any steel cylinder that is not galvanized.
A couple of my cylinders have black factory paint on top of the galvanizing, but I can see the galvanizing finish under the paint. I cut a small rectangle of paint to provide a good spot for stamping the new hydro dates and the galvanize finish is obvious.
If you have a galvanize cylinder with no paint, it should be obvious.
If you have a painted cylinder, it may or it may not be galvanized. If the paint is truly intact, it may be very difficult to tell if there is galvanizing under the paint. But, if the paint has any cuts, it is probably easy to tell if it is galvanized under the paint. If it is not galvanized, you will probably see some orange rust spots.
Norris was sold extensively by Healthways (and a few others). Healthways sold galvanized tanks and in a number of the old catalogs (I just checked 68, 69, and 70) they also had what they called safety yellow tanks. The description of their yellow cylinders in the catalog doesn’t seem to have a galvanizing finish under the paint.
I hope this helps.
OP
The reason I asked is because my hydro shop says that since they are 3AA stamped tanks they "aren't galvanized" and are "regular" steel tanks which don't need the 90% pre-test. That extra step is only for the newer special permit tanks. Technically they are correct but I'd rather be safer than sorry.
I think I talked him into doing it anyways on my tanks, since it's not against the rules, but it would be easier to just prove they are galvanized.
Regarding the yellow tanks, I have one Norris tank where it has a thick yellow epoxy type finish around the sides of the cylinder. Is that what you were referring to as "safety yellow" tanks?
I think I talked him into doing it anyways on my tanks, since it's not against the rules, but it would be easier to just prove they are galvanized.
Regarding the yellow tanks, I have one Norris tank where it has a thick yellow epoxy type finish around the sides of the cylinder. Is that what you were referring to as "safety yellow" tanks?
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your hydroshop has an idiot that is talking to you. All of PST's low pressure tanks to my knowledge were galvanized to the 3AA standard. That said, while the 90% stretch won't hurt them, I don't think there is a real risk of them failing since they aren't normally pre-stretched. The newer permit i.e. HP tanks require it, but that's because their test pressure is also quite a bit higher. The exemption has them tested at 3/2's service pressure instead of 5/3's.
The norris tanks may well be 2250psi tanks which are what mine are, and they passed a "normal" hydro with a + rating and no issues at all
The norris tanks may well be 2250psi tanks which are what mine are, and they passed a "normal" hydro with a + rating and no issues at all
OP
I've had them pass with a "normal" hydro as well, but I figure better safer than sorry.
If the tank is galvanized without a paint finish over the galvanizing, it should be obvious.
My personal observation, is that most 3AA cylinders that were fabricated (until recently) for Scuba are hot dipped galvanized.
I realize that most commercial hydro stations don’t actually deal with many scuba cylinders, but if your hydro tester is looking at a gray galvanized cylinder (with no paint covering the galvanize) and he doesn’t recognize it as galvanize… let’s just say that scares me.
Most commercial cylinders are not galvanized. The only cylinders that I have seen galvanized are scuba cylinders. Therefore, he may not see many, but if he can’t tell the difference between bare steel and galvanize…
I hate to be judgmental, but it does bother me to see someone dealing with pressure vessels that is not well qualified.
All galvanized cylinders should follow the 90% pre-test procedure. The test results are drastically different with the pre-test procedure and it is a manufacturer requirements (from some manufacturers).
Yes, that heavy yellow coating is probably from Healthways. Many of the Healthways cylinders had a serial number that started with HJ.
The safety aspect of it was just the color for visibility. There was nothing else special about it.
Can you tell if there is a galvanize finish below the paint?
My personal observation, is that most 3AA cylinders that were fabricated (until recently) for Scuba are hot dipped galvanized.
I realize that most commercial hydro stations don’t actually deal with many scuba cylinders, but if your hydro tester is looking at a gray galvanized cylinder (with no paint covering the galvanize) and he doesn’t recognize it as galvanize… let’s just say that scares me.
Most commercial cylinders are not galvanized. The only cylinders that I have seen galvanized are scuba cylinders. Therefore, he may not see many, but if he can’t tell the difference between bare steel and galvanize…
I hate to be judgmental, but it does bother me to see someone dealing with pressure vessels that is not well qualified.
All galvanized cylinders should follow the 90% pre-test procedure. The test results are drastically different with the pre-test procedure and it is a manufacturer requirements (from some manufacturers).
Yes, that heavy yellow coating is probably from Healthways. Many of the Healthways cylinders had a serial number that started with HJ.
The safety aspect of it was just the color for visibility. There was nothing else special about it.
Can you tell if there is a galvanize finish below the paint?
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OP
The yellow coating is still pretty intact. There were only a few small cuts/scrapes of about 1" each and it did not look rusted underneath. So hopefully galvanized as well.
I have one USD orange painted one that is galvanized beneath the paint (most of which is flaked off already).
I have one USD orange painted one that is galvanized beneath the paint (most of which is flaked off already).
halocline
Contributor
I think it was really common to have galvanizing underneath the paint on LP72s. My PSTs are like that. It was fairly easy to remove the paint and leave the galvanized finish mostly intact. Then I sprayed some ZRC galvilite over the galvanized primer and 10 years later they look fine.
I had trouble with the first hydro place I took them. He refused to do the pre-round out procedure. They passed hydro but did not qualify for the + rating by a fraction of a CC, so he stamped the words "no plus" on the tanks. This experience did not do much for my bad attitude about hydro shops.
I had trouble with the first hydro place I took them. He refused to do the pre-round out procedure. They passed hydro but did not qualify for the + rating by a fraction of a CC, so he stamped the words "no plus" on the tanks. This experience did not do much for my bad attitude about hydro shops.
OP
I know I can at least get the + from this shop. Fingers crossed on if he actually does the pre-round procedure and if the tanks pass...
Do you mean you re-primed and painted ZRC over the original galvanized finish?
Do you mean you re-primed and painted ZRC over the original galvanized finish?
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