The elusive "PLUS" rating?

[Scott L]

Here, in one of the busiest dive ports in the world, I do not know of one fill station which delineates between a plus rated hydro stamp or one without. Generally, not worth the hassle IMO.

A personal relationship with an LDS, including using the same facility for visuals will usually net over-fills...

 

[chrpai]

Can a tank be tested for a plus rating at the next hydro if the previous hydro didn't have a plus rating? ( possibly not tested for plus rather then failed )

(Looking for a fact here not an opinion)

 

[Jim Lapenta]

My understanding is that yes it can. You may need to contact the tank mfg to get the specs and procedure to take with you to the hydro shop though. Not a bad idea to do that anyway. The shop should have them anyway but we all see how things get "lost" or "misplaced" and "oh we didn't think we could do that" when people get lazy.

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[spectrum]

The + stamp usually does not get renewed for 1 of 2 reasons.
1) The shop didn't bother to take the extra steps because the owner did not explicitly ask to seek the + rating
2) The shop did not have the REE number. This factor is needed to calculate eligibility.

So...
3)Tell the shop you want to seek the + rating
4) Ask if they have the REE number. if the say "no", take your cylinder home and email the manufacturer with all of the factory stampings asking for the REE number.
4a) If the glaze over when you say REE find another shop.

Even if it failed the REE cutoff previously nothing gets defaced so a subsequent test is very possible.

Also while you are at it... If it's a galvanized cylinder make sure that will perform the rounding procedure prior o the actual hydro test. You can search for details on that. Doing so lets the cylinder demonstrate it's true properties with a higher likelihood of a premium rating.

Pete

 

[ktomlinson]

Can a tank be tested for a plus rating at the next hydro if the previous hydro didn't have a plus rating? ( possibly not tested for plus rather then failed )

(Looking for a fact here not an opinion)

I just got two tanks back that didn't previously have a + stamp and now they do.

 

[chrpai]

Thanks guys! Times like this I really appreciate the power of scubaboard. Having someone to ask when there is a gap in my knowledge or experience.

 

[halocline]

Can a tank be tested for a plus rating at the next hydro if the previous hydro didn't have a plus rating? ( possibly not tested for plus rather then failed )

(Looking for a fact here not an opinion)

Yes it can. It could also fail a plus rating at one hydro, pass it at the next, and get the plus rating. There is no additional test for the plus rating; the tank is pressurized to test pressure and expansion measured just like any other tank. The total amount of expansion can't exceed the REE number for that tank to get the plus rating. That's all there is to it. Then the tank is depressurized, and if it returns to no larger than the original volume plus 10% of the expansion, it passes hydro.

It's disturbing how clueless so many shops are about this very simple procedure.

---------- Post Merged at 07:47 AM ---------- Previous Post was at 07:45 AM ----------

Even if it failed the REE cutoff previously nothing gets defaced so a subsequent test is very possible.

Pete

I had a local hydro shop stamped the words "no plus" in one of my LP72s because I had asked for the plus rating and they could not find the REE.

Amazing.......

 

[616fun]

I was told locally (Indianapolis) that the issue is not how to calculate if the cylinder passes the '+', but that there is an additional qualification that must be submitted to the DOT to be capable of issuing a '+'. Since scuba cylinders are a very minimum piece of their business it is not financially viable to pay for the additional certification. I can't find any DOT regs that confirm or deny this.

Anyone have any insight?

 

[idive2]

Here, in one of the busiest dive ports in the world, I do not know of one fill station which delineates between a plus rated hydro stamp or one without. Generally, not worth the hassle IMO.

Scott, it kinda depends on the shop doing the fill. This coast seems to give pretty decent fills but there are shops in other
locations that go by the letter of the law. I have two identical tanks and unfortunately when dropping one off for a hydro
it was returned without the plus rating. They are late model low pressure steel tanks and while most shops will fill them the same
with a decent fill there are some shops that will not fill to plus rating when the last hydro does not have the plus rating. Anyone getting
a hydro on a low pressure steel should confirm first that the station will do the plus rating. There are shops that will make a fuss over it.

 

[captain]

I was told locally (Indianapolis) that the issue is not how to calculate if the cylinder passes the '+', but that there is an additional qualification that must be submitted to the DOT to be capable of issuing a '+'. Since scuba cylinders are a very minimum piece of their business it is not financially viable to pay for the additional certification. I can't find any DOT regs that confirm or deny this.

Anyone have any insight?

If the hydro shop does not have the tank manufacture's calculated REE number and has to determine the REE from one of several methods that requires some engineering and mathematical expertise then maybe some certification is required but not to my knowledge. As was previously stated if the shop has the manufacture's document stating the REE or the REE is plainly stamped on the tank by the manufacturer than the process is farm animal simple. What has happened over the years is some of the documentation for older discontinued cylinders has been lost over the years. The REE for the old Norris manufactured 72 seems to have been lost by Norris. A shop that has been in business for 50 years may have it on record but newer shops probably won't and can not get it and have neither the knowledge or interest to calculate it.