300 bar to 200 bar DIN adaptor?

[redacted]

PS. Each of my DIN regulators has 5 threads, which as I understand are the 300 bar ones. So my impression is I already own the best available kits.

5 threads is 200 bar. 7 threads is 300 bar. Neither should have any trouble handling 3500 psi.

DIN Scuba Fittings

 

[raftingtigger]

5 threads is 200 bar. 7 threads is 300 bar. Neither should have any trouble handling 3500 psi.

DIN Scuba Fittings

Thanks awap, very helpful link.

 

[Peter69_56]

Ah ha, the famous SB "you are going to die".

3. My fix traps a standard scuba o-ring and a ss washer in a place it cannot dislodge while in use. It might leak, but after 72 hours under pressure it hasn't yet.

4. The common scuba repair shop way to use a SP universal DIN kit on a SP MK5 is to insert a brass or SS washer between the first-stage body and the DIN kit. What I am doing here is essentially the same thing.

"It might leak, but after 72 hours under pressure it hasn't yet", how many trips did the shuttle do before it blew up due to a faulty O ring. Their logic was, we have done some 25 launches and one O ring was damaged and we got away with it thus all is OK.

I have just completed a Scuba Tech course and their philosophy is simply do it right with the correct gear, or don't do it at all.

See rule 1 "You don't know what you don't know until you get there, and often then its far too late"

 

[raftingtigger]

"It might leak, but after 72 hours under pressure it hasn't yet", how many trips did the shuttle do before it blew up due to a faulty O ring. Their logic was, we have done some 25 launches and one O ring was damaged and we got away with it thus all is OK.

I have just completed a Scuba Tech course and their philosophy is simply do it right with the correct gear, or don't do it at all.

See rule 1 "You don't know what you don't know until you get there, and often then its far too late"

So noted. The 72 hours holding pressure is just the first step. Unlike the shuttle o-ring the only failure mode I can realistically see is a loss of all gas from that cylinder. This is something I am taking account for. Clearly you don't like the idea, and that is OK. Since you are in Australia and I am on the California coast I don't think the tsunami if the connection leaks will affect you.

What would add to the thread is discussion of realistic failure modes. So far it has been established that 5 threads of the DIN connector are engaged, that is the 232 BAR number, the tank is rated to approx the same BAR, and the regulators being used are rated to at least​ 232 BAR.

Now Peter69_56, if you really want to expand your mind then go check out what has been successfully done on the DIY forum, or not if you don't think that way. Anyway I respect your opinion, just don't agree with it unless you can support it with facts and/or a logical and reasonable failure chain.

 

[redacted]

"It might leak, but after 72 hours under pressure it hasn't yet", how many trips did the shuttle do before it blew up due to a faulty O ring. Their logic was, we have done some 25 launches and one O ring was damaged and we got away with it thus all is OK.

I have just completed a Scuba Tech course and their philosophy is simply do it right with the correct gear, or don't do it at all.

See rule 1 "You don't know what you don't know until you get there, and often then its far too late"

While the risk of a valve o-ring failure may be somewhat increased, the impact is no different than it would be with a 300 bar connection. Gas will leak out fairly quickly and the dive will come to an end.

Of course this is not what I would expect a "Scuba Tech" to do for a paying customer. But it looks like a perfectly adequate work around with no significant safety drawback for a recreational diver.

 

[Tigerman]

Just change out the 200 bar din fitting on your reg for a 300 bar fitting. That way it will fit any din valve you come across in the future.

The above is not quite true. If you go to Europe & want to dive nitrox, you'll need a new, you beaut, EU nitrox fitting.

I'm yet to see one of those mythical things...

 

[NotSure]

If you have a 300 BAR valve and a 232 bar din connector how is it that you have 5 threads engaged. A 300 BAR DIN connector on a 232 BAR valve only has 5 threads engaged according to my understanding and the link AWAP provided. If you have a 232 BAR DIN connector the center portion that is described in AWAP's link is what is preventing a good seal. I think you need to do a few measurements to determine exactly how far the din connector is going in and compare the difference with the thread length.

 

[raftingtigger]

NotSure. Good points. We are getting away from my original post - that I found a potential adaptation to my problem (and one that others might find helpful) - but that is pretty normal here on SB and it is bringing up some interesting points.

At this point taking good measurements is a very good idea. Very little is making sense at this point except that I do seem to have a temporary work-around. Everything I can find online suggests that all my female DIN connectors are 300 BAR. All were bought new (in 2014) and from reputable dealer authorized dive shops. The valve on the problematic tank should be a 7/8 UNF 300 BAR DIN according to this https://www.divegearexpress.com/library/valves.shtml

I had assumed ("ass -u & me") that it was a 200ish BAR and 300 BAR issue, but after the back and forth and looking up equivalent parts on the internet it looks more subtle than that. I'll post measurements when I can.

 

[Peter69_56]

So noted. The 72 hours holding pressure is just the first step. Unlike the shuttle o-ring the only failure mode I can realistically see is a loss of all gas from that cylinder. This is something I am taking account for. Clearly you don't like the idea, and that is OK. Since you are in Australia and I am on the California coast I don't think the tsunami if the connection leaks will affect you.

What would add to the thread is discussion of realistic failure modes. So far it has been established that 5 threads of the DIN connector are engaged, that is the 232 BAR number, the tank is rated to approx the same BAR, and the regulators being used are rated to at least​ 232 BAR.

Now Peter69_56, if you really want to expand your mind then go check out what has been successfully done on the DIY forum, or not if you don't think that way. Anyway I respect your opinion, just don't agree with it unless you can support it with facts and/or a logical and reasonable failure chain.

I do enjoy looking at DIY and appreciating what can be done by an enterprising person. Perhaps my reluctance is due to being taught to "do it right" if at all possible. In hindsight I agree provided you maintain tank pressure at 230 BAR or less the risk of blowing an O ring is minimal. As the next post stated "Of course this is not what I would expect a "Scuba Tech" to do for a paying customer" and he is so right, I would not even entertain the idea as a fix for a customer.

For me its about principles, DIR if possible. For you, perhaps its a different view. Each to their own view.

 

[Itsacon]

5 threads is 200 bar. 7 threads is 300 bar. Neither should have any trouble handling 3500 psi.

DIN Scuba Fittings

300 Bar = 4351 PSI.

US HP (3500 PSI) is DIN 200, which is rated to 232 bar.

Like I said: If the tank has a 300 Bar valve, it can be filled to that pressure. So connecting something that can't is asking for problems.

So noted. The 72 hours holding pressure is just the first step. Unlike the shuttle o-ring the only failure mode I can realistically see is a loss of all gas from that cylinder. This is something I am taking account for. Clearly you don't like the idea, and that is OK. Since you are in Australia and I am on the California coast I don't think the tsunami if the connection leaks will affect you.

What would add to the thread is discussion of realistic failure modes. So far it has been established that 5 threads of the DIN connector are engaged, that is the 232 BAR number, the tank is rated to approx the same BAR, and the regulators being used are rated to at least​ 232 BAR.

Now Peter69_56, if you really want to expand your mind then go check out what has been successfully done on the DIY forum, or not if you don't think that way. Anyway I respect your opinion, just don't agree with it unless you can support it with facts and/or a logical and reasonable failure chain.

If that's the only failure mode you can see, you have very little imagination. Remember that the valve is pointing at the back of your head. If that o-ring doesn't hold, you've have 300 bar (over 4000 psi) pointing straight at your head. Even just air hurts at that pressure.

If that tank is only rated to 232 bar, and there's a 300 bar valve on it, you have more serious problems, cause it should never have passed its last inspection.