"Industry Standards (US)" What are they?

[elan]

(I thought part of this test was to use a straight edge and measure the bow of the cylinder while under test pressure). .

No this is incorrect. The bow is measured at the visual stage without any pressure. The hydro is done with a cylinder filled with watter sumberges into a water bath. Noone in clear mind will be measuring a bow under test pressure. It would be like measuring a bow of a hand grenade with a charge that has been set off

 

[Wookie]

The tank primates on your female sibling's boat definitely need to get a clue.

I am completely divorced from that particular boat.

Can anyone tell me if its necessary to clean a Nx cylinder after a hydro if it was clean up to then. I have 2 60% Nx sling cylinders and when I got them hydro'd yearly per aust rules they re-cleaned them. Is there a reason why this must be done due to how they hydro them or is it more a money making exercise

Some hydro shops have a clue, some don't. Hydro shops hydro more than just SCUBA cylinders, they also hydro oxygen cylinders. If you tell the hydro shop that the cylinder is for Oxygen service, then they will send it back O2 clean. If not, I've seen some of the nasty water that comes out of a cylinder from hydro. 'Round here, they will use a rust inhibitor that is also an oxygen cleaning agent in the hydro water, especially for steel cylinders. Be up front and honest about your expectations and hope they can meet them.

 

[elan]

KWS did not you guys go through this expiration nonsense in your PSI class?


There is no such thing as a vis expires in a year or the sticker is valid for one year and the inspector open himself to all legal crap when they put a sticker with any indication of an expiration. All that the sticker indicates is that the tank was inspected and/or cleaned on the posted date and conforms to XYZ reccomendations on that date. One day later the diver can fill the tank with crap and so why would I as an inspector put a sticker that is "valid" for a year.

Its up to the filler to make a decision pn what expiration period to accept. They can agree on 2 years or 2 days. The latter might cost them business though. So most kind of agreed to 1 year but thats just a state of affairs not a law or recommendation. The compressor owner makes the rules we vote with our wallets

Why does a VIS expire at the beginning of the indicated month?
The vis sticker is valid for UP TO one year. If the vis was done on say july 1 then it would be void the next july 1. as no date is on the sticker worst case dictates to treat them as done on the 1th of the month.

 

[Wookie]

Its up to the filler to make a decision on what expiration period to accept. They can agree on 2 years or 2 days. The latter might cost them business though. So most kind of agreed to 1 year but that's just a state of affairs not a law or recommendation. The compressor owner makes the rules we vote with our wallets

In Key West, the shop that rented steel tanks no longer does so because someone rented one and filled it from a compressor that hadn't been maintained as well as theirs. Trashed the steel. I completely understand. If I lend out a cylinder, it goes with the provision that it doesn't get refilled by anyone but me. My steel cylinders never get lent.

 

[redacted]

Yeah cause they probably have some insurance underwriter that says otherwise. Better write them as well.

Isn't it a bit suspicious that statements like this keep popping up but no one is willing to post an excerpt from an insurance policy proving it.

 

[Scared Silly]

Isn't it a bit suspicious that statements like this keep popping up but no one is willing to post an excerpt from an insurance policy proving it.

That is why I said "Better write them as well." You want definitive answers, so instead of posting your interpretation of the CFRs or agreeing/not agreeing with the other's interpretation write the fricking agencies and insurance companies and get something in writing.

Here to help ya get started here are two well known names in the scuba insurance game.

Scuba Insurance - Scuba Diving, Equipment, Dive Store Owner Insurance

Vicencia & Buckley Insurance Services, Inc. - Dive Insurance, Dive Boats, Dive Store/Resorts, Professional Liability

 

[NAM001]

You are literally correct, the sticker only reflects the status at the time of the inspection. We had some info as to what constituted normal tank use, inregards to cylendar cracking and that is where we got the normal usage was 2 fills a week. Higher fill rates called for more agressive periodic visual inspection frequency. I never said the sticker was good for a year , I said it was good for a max of one year. Any use that would cause reason to inspect more frequently should result in more frequent inspection, IE you received a tank of bad air as you have posted. A foul smell in the air says something is not right in the tank and should be placed out of service until a thorough inspection of its contents has been made.

Elan i think we are speaking the same. Just wording it differently. Clearly i am not suggesting that the vis sticker will protect your tank for a 1 year period any more than a dive cert will protect you from dieing.

To answer you expiration question directly, Yes we did. The sticker is valid for up to one year and expires in the month stamped on the sticker. The year stamped,,, in the year of the inspection as not to be confused to being the year of the expiration for the purposes previously mentioned. Anything that would cause a need to reinspect earlier that the norm of 1 yr would be things like, air with an odor, tank has been damaged or in an environment that may have caused damage to the cylendar. such things would include tank in vehicle that was involved in an accident. tank dropped such that it became gouged. an example that ws provided was a tank that was hit by a porprller and gouged the tank deeper than allowed. the 1 year vis was void at that moment. fill monkeys are supposed to do a quick visual inspection of each tank among other things prior to filling to detect possible damage to a tank suggesting that a visual shoul be done prior to further ussage. All this was in my course Including issues of stress related cracking which was the soursce of the issue of "nornal tank usage was" 2 fills a week and that the vis was good for up to 1 year for tanks of normal usage. Those who rent tanks or are operators should evaluate the tanks usage to determine how frequent inspection should be done not to exceed the max of 1 year. I can not comment on what was in your course, ro whether mine was any more accurate or less than yours. only what was taught in mine. I think it is pretty common sence that boat filled tanks has a higher PROBABILITY of having moisture in them than shore filing stations. any filling that is done by removing the reg and filling has a higher chance of water than a tank that sits for a day and then gets filled.

As a reference to this i offer the book INSPECING CYLENDARS put out by PSI 4th edition chapter 6. As to what is the base documents for this is i do not know off hand and although i could find out i am not going to.

KWS did not you guys go through this expiration nonsense in your PSI class?


There is no such thing as a vis expires in a year or the sticker is valid for one year and the inspector open himself to all legal crap when they put a sticker with any indication of an expiration. All that the sticker indicates is that the tank was inspected and/or cleaned on the posted date and conforms to XYZ reccomendations on that date. One day later the diver can fill the tank with crap and so why would I as an inspector put a sticker that is "valid" for a year.

Its up to the filler to make a decision pn what expiration period to accept. They can agree on 2 years or 2 days. The latter might cost them business though. So most kind of agreed to 1 year but thats just a state of affairs not a law or recommendation. The compressor owner makes the rules we vote with our wallets

---------- Post added March 18th, 2013 at 01:25 PM ----------

As for a previous comment of documantation in regards to inspeation ect here are some references CGA

c-1 methods for hydro testing of compressed gas cylendars
c-5 cylenday service life seamless steel hp cylendars
c-6 standards for visual inspection of steel cylendars
c-6.1 standards for visual inspection of aluminum cylendars
c-6.2 guidlines for visual inspection of FRP cylendars

 

[rjack321]

Simple answer, the shop doing the VIS of course. In Australia tanks have to be hydro'd and vis every 12 months. I just had mine done and what I found offensive was that I didn't want the manifold on my twin cylinders to be serviced, but asked to have the cylinder neck O rings replaced and was told they would NOT do it unless I paid an additional $100 to have the manifold serviced. With my Nitrox cylinder which was current and clean to 100% I was told I had to pay for another clean during the hydro & test process. Why? If its clean all they introduce is water to do the hydro test, dry it and the visual inspection and reassemble so why the need to do another clean??? Seems rorting to me.

The water at the hydro shop is nasty old crap with rust and who knows what else in it, its reused and been in countless mystery cylinders before. Afterwards its common practice to steam wash the finished cylinders as the hot water speeds drying. They are sometimes "O2 clean" after this practice and sometimes not. If you have ever seen an O2 fire, particularly in an AL cylinder which is great fuel, you'd understand the reticience of the shop to trust anyone else's post-hydro cleaning.

 

[Scared Silly]

Y
As for a previous comment of documantation in regards to inspection ect here are some references CGA

c-1 methods for hydro testing of compressed gas cylendars
c-5 cylenday service life seamless steel hp cylendars
c-6 standards for visual inspection of steel cylendars
c-6.1 standards for visual inspection of aluminum cylendars
c-6.2 guidlines for visual inspection of FRP cylendars

Regarding visuals for scuba cylinders and frequency:

CGA P5 Suggestions for the Care of High Pressure Air Cylinders for Underwater Breathing

Which before anyone gets their hoses in knots - the above is not referenced by any CFRs and is not law. Further, they are suggestions not requirements.​

 

[Peter69_56]

The water at the hydro shop is nasty old crap with rust and who knows what else in it, its reused and been in countless mystery cylinders before. Afterwards its common practice to steam wash the finished cylinders as the hot water speeds drying. They are sometimes "O2 clean" after this practice and sometimes not. If you have ever seen an O2 fire, particularly in an AL cylinder which is great fuel, you'd understand the reticience of the shop to trust anyone else's post-hydro cleaning.

I have had this cylinder tested at the same shop that did the prior test and clean so no excuse that "someone might have done a bad job last time. However if the standard is to do a clean after test each time I accept it as the "Norm". If however most don't do it unless they have an issue with the cylinder or they didn't do the previous clean and the shop I pick does it every time, then I do have an issue. In that case it would seem over servicing. I don't mind paying reasonable prices for quality work and to the "standard", but hate being ripped off by people who don't do what they charge for or over service. Ok understand about the bow check not being under pressure, however how do you do this with the tank mesh on and tape on? Suspect someone is not doing the service as per the spec, just charging for it.