232 bar Vs. 300 Bar Manifold

[TSandM]

I'm with ae3753 -- Just about every time I assemble my gear, I mutter, "I hate 300 bar manifolds." Since there really is no good reason to have them, why put up with the annoyance?

 

[rjack321]

It depends on the test pressure of the specific tank and by DOT reg, the burst disc must fail within a range of 90% to 100% of the test pressure. Special permit steel tanks usually have a test pressure in the neighorhood of 3/2 the servcie pressure while 3AA and 3AL tanks use a test pressure of 5/3rds the service pressure.

The OP has 3442psi tanks, which are hydroed at 5250psi. He could use a 5000psi burst disk or (shudder!!) none.

 

[rjack321]

Most regs have 300 bar threads. I like the way they look in the 300 bar valves better than the 200 bar valves. I always stop and make sure the reg is screwed all the way in on a 200 bar reg.

A cosmetic reason, but about as good as any.

Tom

One will get slightly out of round or not seal with a particular reg someday and that will negate all the years of prettiness dang quick.

I still have some 300bars that I have to have (3500psi 78" valved tanks) and some that came on used cylinders. And I have had a few that I had to throw out when the opening got out of round.

 

[lamont]

As others before me stated, either is fine.

In retrospect, I should have gotten 200 bar for all my manifolds and stages. Those few extra turns add up for me. Yes, I'm getting lazy.

Life is too short. I've wasted too much of it on all those extra turns...

 

[b1gcountry]

Well, this way, when I'm the last one ready for a dive, I can just blame it on the valve taking too long to screw in.

I guess you guys just want to get it in as quick as possible so you can get wet. That's why women give us a hard time, you know...


Tom

 

[nadwidny]

I'm with ae3753 -- Just about every time I assemble my gear, I mutter, "I hate 300 bar manifolds." Since there really is no good reason to have them, why put up with the annoyance?

At one time George (and possibly JJ) posted on why the 300 was preferred over the 200.
I can't remember the exact details but it had something to do with things shearing off in an overhead impact.

Whether or not it is a good reason is up for debate.

 

[rjack321]

At one time George (and possibly JJ) posted on why the 300 was preferred over the 200.
I can't remember the exact details but it had something to do with things shearing off in an overhead impact.

Whether or not it is a good reason is up for debate.

Yeah I recall something like that. At least for SP regs its erroneous. The weakest part is where the DIN fitting steps down to much smaller diameter and threads as it goes into the body. Or possibly the body itself, as evidenced by the recall on the mk20s due to overzealous torquing by some NOAA techs.

 

[RTodd]

Arguably, 300 bar helps better protect the threads of the reg and yes I have even see the one, very, very rarely, "ring" the cave with his valves. For just the backgas I don't find it that big of a deal to make the few extra turns and it does at least protect the threads and make it harder for a hit to dislodge the seal (talking leaking here, not shearing off the regs). For stage regs, owning mostly 300 bar valves annoys me to no end. The speed argument used to be used for using yokes for stages and it is more convenient. But, consistency and the better seal of DIN has won that argument.

 

[mikeguerrero]

Most regs have 300 bar threads. I like the way they look in the 300 bar valves better than the 200 bar valves. I always stop and make sure the reg is screwed all the way in on a 200 bar reg.

A cosmetic reason, but about as good as any.

Tom

I'm with Tom on this one:

I own DIN regs and have the 200 DIN/Yoke 100hp tanks. The first thing I noticed was that the last couple threads didn't screw in. At first I thought there was a problem until I read about the 200 vs 300 debate.

Even though both are equal in performance, I simply didn't like the way the last three threads are exposed to ocean salt and any other things found in ocean water. I started noticing that as I remove my 300 bar DIN regs the last three threads are not as shiny and nice as the ones that are seated deep within the DIN 200 valve.

So when I got my new 19cf pony I made sure to order at 300 bar valve to complement the 300 bar DIN reg, I now don't have that problem with the exposed threads that have contact with ocean water.

As lame as that seems it's just a personal preference on how tidy I am with all of my equipment.

When I get doubles I'll be sure to get my DIN 300 valves. Having said that my Argon reg is 200 BAR yes very tiny and cute, it fits onto the 200 BAR valve 6cf tank I have, fits and locks all the way in.

If the Regs I owned were 200 bar I'd be happy with the convertible valves I have DIN/Yoke.

MG

 

[DIR-Atlanta]

For just the backgas I don't find it that big of a deal to make the few extra turns and it does at least protect the threads and make it harder for a hit to dislodge the seal (talking leaking here, not shearing off the regs). For stage regs, owning mostly 300 bar valves annoys me to no end.

I agree on these two points - all my doubles are 300 bar, and all my stages are 200 bar, pretty much for the same reasons outlined by RTodd above. One other thing I like about the 200 bar valves for stages is that they are DIN/Yoke convertible, which allows one to use either type reg in a pinch.