What do the numbers on scuba tanks mean?

[runsongas]

@KWS Visual inspectors can also be trained to the CGA standard and are frequently done so for the industrial gas industry.

 

[rhwestfall]

03^19 should be the manufacturers first hydro date which happens at time of manufacture

which is the "born on date"....

 

[NAM001]

@KWS Visual inspectors can also be trained to the CGA standard and are frequently done so for the industrial gas industry.

that is correct but no one did that to its full compliance until PSI did it. doing it independantly is not a problem but when the competition steels your work and calls it their own that is another thing.

 

[NAM001]

which is the "born on date"....

i agree,,,,, the actual symbol is the hydro stamp

 

[NAM001]

I’m not going to get into details other than to say I’ve experienced first hand scare tactics & trashing of competition that I find distasteful. Just because you’re first at something doesn’t mean others aren’t allowed to enter your market and compete. Compete by being better not by pressure & fear. Enough said about that.

we will have to just disagree. I have heard stories regarding perhaps what you are saying and it came down to the shop did not comply with CFR's for fill stations and other matters. owners do not like being told they are wrong. I dont agree with some things that they put out,,,, however they have the federal backing for what they say. When one complying shop makes a complaint against another shop ,,,,, one has to be the looser in the opinion. It would not surprise me if other agencies are notified about shops not in compliance. rightfully or not that stuff happens when a pissing contest developes. I can readily see if a complaint was made,,,,,, PSI may have been brought in as a 3rd party to evaluate a shop. Especially if there were other legal issues at stake or there is a war between shops.

 

[Storker]

I actually know why. I mentioned that I run DIN. 3500 is the maximum working pressure Yoke regulators withstand, past that and you get leaks and your A-clamp can blow off the valve

No, what I was saying wasn't "why not 3500". I said "why not 3400".

3400 is a fairly nice, round number. Also, 3400 psi is 235 bar which is closer to our standard 232 bar (why not 235?) and a little further away from 3500 psi than your current 3442.

If they'd listened to me (which neither my kids nor my wife do very often, so there's that) you guys would have 3000 psi and 3400 psi working pressures - plus those weird LP and "+" things - and we'd have 200, 235 and 300 bar.

 

[runsongas]

that is correct but no one did that to its full compliance until PSI did it. doing it independantly is not a problem but when the competition steels your work and calls it their own that is another thing.

PSI/PCI made a business of it, but that doesn't mean they were first. the CGA visual inspections predate the invention of scuba.

 

[NAM001]

PSI/PCI made a business of it, but that doesn't mean they were first. the CGA visual inspections predate the invention of scuba.

Not what I meant by saying the first at it. CGA was one of many agencies. osha DOT and others had some form of jurisdiction. PSI was the first to put all these agencies together test their standards against the CFR"S and made those cfr contents the standard to do business by ;inthe scuba community. OSHA has little to any say if there is something contradicting in a CFR. Yes PSI made a business at doing that. they were the only one. They offer their services for training for compliance and if you are in compliance they will defend you in a suit. that made PSI's set of standards the milestone of litigation mitigation. PSI will even say they may not like something but the fact that something is in the CFR makes it boss and if yo do not comply you are subject to suit. As far as I know PSI is still a one team sport. There is a question on the test that is basically this. a tank maker has changed its recommendation form doing a process from one year to 2 year intervals. the CFR's say do every year. If an incident arrises regarding that makers tank and you complied with the manufacturers 2 year interval are you at fault. The answer is YES because CFR's supercede manufacturers specs. Although you met the makers requirements you did not meet the federal established requirements. If you meet the CFR's you are OK and if you meet the makers also even better. there is another version of the question. It is very much like the issue with covid recovery....... is an EO enforcable???? makers recommendations are recommendations but CFR has force of law.

in regards to you r post about cga predates scuba. that is true. then enters osha. dot ct special permits. commercial vs private. and yet I do not recall anything that psi pas put out that relates t opersonal use. such as it is illegal for a comercial venture to fill a tank that has past due hydro. nothing is there for private fillers. does a license make your fill a commercial act and covered by the agencies? is quid pro quo make a home fill a paid service? lots of oopinions on those aspects. Most often when debates happen one person says one thing and someone counters with oshsa'a position than someone else counters that with dot et. Most of the cfr's are not "use" specific as scuba goes. there are portions that are though. not specific wold be you can transport a tank past hydro that is filled but you cant fill a tank that is past hydro. that is written that way because the tank contents are not relevant. the tank could be have toxic contents and you have to ship it some how to a proper handler for those contents. ther are always issues that people claim a scuba tank is not hazardous material.

When it comes to other agencies and taking PSI materials it is no different than china taking our technology and profiting from it. At minimum it is copywrite infringment. The idea that your concepts are not yours has been a long battle over the years. Lots of lawyers have made lots of money to find ways to legally steal the property of others. A lot of money is spent to convince the powers that an ambulance with 4 lights is not the same as one with 5 lights and that the 5 light version is something new and not a copied version of someone elses design..

 

[Bob DBF]

I'm uncertain of the exact details but yoke valve connections have a maximum permitted pressure that is around 3300 PSI or 230 bar, so the original HP cylinders had DIN valves and 7/8" necks so they wouldn't be compatible with the yoke valves for safety. Somewhere along the line someone found a way to get an approval for 230 bar service based on a liberal conversion ratio between bar and PSI that resulted in a 3442 PSI service pressure.

The maximum permitted for a yoke is determined by the strength of the yoke. I have a Sherwood from around 1980 with a yoke made for 4000# service. Both yoke and din connections use a flat metal to metal seat with a sealing o-ring the difference is how they are attached and placement of the o_ring.

The issue with yokes is there have been many "standards" over the decades back to the 1800# service pressure tanks when recreational SCUBA started. I would guess the 3500# limit for yoke was to reduce the likelihood of an accident with an old yoke, and there was a euorpean standard in place for higher pressure scuba regulator connection, with a change to tank threads to insure a yoke valve could not be used in the tanks.

The tank itself and the valve can handle a bunch more pressure, the pressure you are allowed to fill to is decided by how you attach your 1st stage to the tank, by a Yoke or a DIN. It's just safety regulations.

By the way, when I filled the tank on monday, I checked with my dive computer and the pressure was 3540. If I was using a Yoke I probably would have had problems.

I agree the difference is for safety, but the pressure you allowed to fill is up to the tank monkey. I have an Faber MP 120, service pressure is 3180 with the + the fill is3498#, a fill to 3540 is not all that uncommon and my 2010 Sherwood Blizzard yoke reg has never had an issue with the pressure. The safety issue is what happens if I use my old Magnum from 1980 or one of my vintage regs at that pressure, especially ones made prior to 3000# service.

 

[runsongas]

@KWS

OSHA and DOT are governmental agencies. In setting up the CFR, DOT and PHMSA adopted the standard proposed by the CGA. The CGA standard is the actual law in 49 CFR Subpart C 180, not PSI/PCI. PSI/PCI trains to a standard that is compliant with CGA then adds their scuba oriented spin on it. If you also read the CFR, you will see that yearly visual is NOT required. The visual requirement is before hydrostatic testing.

PSI/PCI has always pushed for yearly visual as part of their training and has tried to bamboozle everyone to thinking that legally you have to be a PSI/PCI inspector and do a yearly visual in order to be compliant with the CFR when that is not the case. With that said, the yearly visual is not a bad idea due to how poorly some tanks are treated.

Also, who are you saying is "stealing" PSI/PCI's work? Everybody involved is basing it off the CGA standard anyways since that is the actual requirement per the CFR.