232 bar Vs. 300 Bar Manifold

[ScubaInChicago]

I'm in the market for a new doubles manifold and have heard a couple of views each way. I've read the DIR book and there's not a clear answer there either.

I'm picking up a couple of Worthington HP 3442 X-8 130 tanks and have heard that the burst disks can and should be upgraded to a higher psi rating with either version of the manifold. Also have heard that the 300 bar is more delicate and can be damaged and become out of round easier than the 232. I've also heard that fills can be a problem when a LDS doesn't have a din coupling whereas you could screw in a yoke plug in the 232 version and get a fill anywhere.

Thanks for any insight, I prefer to buy the right equipment the first time and I apologize if this issue has been discussed before but I couldn't find one in a search.

 

[Rainer]

Either is fine.

 

[DA Aquamaster]

I am in agreement with everything you've said regarding the pros and cons of 232 and 300 bar valves. 300 bar valves just don't make much sense given that 300 bar (4350 psi) fills are not common in the US.

The deeper valve was mainly intended to ensure regulators that could not withstand 300 bar/4350 psi service pressures could not be connected to 300 bar/4350 psi tanks as the shorter 200 bar DIN connection would not seal in the longer 300 bar valve. The extra threads had nothing to do with the strenght of the connection.

The proper burst disc assembly in a 3442 psi tank should burst in a range of 90% to 100% of the test pressure (5160 psi) - a range of 4650-5160 psi and that is plenty for a 3442 psi tank as long as you change it out every 5 years when you hydro test the tank.

 

[rjack321]

The official DOT proper burst disk is 5250psi (= hydro test pressure). Some manifolds are provided with unmarked burst disks, be sure to ask what was installed. Higher ratings than that are available but not spec, and somewhat difficult to find.

Otherwise get the 200 bar, 300 bar has no advantages here in the States for all the reasons you state.

 

[stairman]

Ive had a 300bar manifold for years with no problems. A few more turns at the fill whip maybe. As stated either is fine.

 

[Scared Silly]

With either buy your own DIN-Yoke fill adapter and bring it with you when you get fills. Once my shop could not find theirs - so I went home and got mine. Lesson learned bring your own.

The other is buy some DIN plugs for keeping crap out of valves during transport and storage as well protecting them from damaged. Often you can get these for $15-$20.

 

[ae3753]

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.

 

[DA Aquamaster]

The official DOT proper burst disk is 5250psi (= hydro test pressure). Some manifolds are provided with unmarked burst disks, be sure to ask what was installed. Higher ratings than that are available but not spec, and somewhat difficult to find.

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.

 

[gxsr_sarge]

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.

Ditto!

 

[b1gcountry]

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