Din 1st Stage

[cummings66]

I thought so, around here it's rare to see 200 bar stuff while the 300 bar stuff is much more common. Mine is all 300 bar, even the new old tank I bought is 300 bar.

 

[Divin'Papaw]

It looks like you have your answer. Yes, you can use a 300 bar DIN regulator 1st stage on a 200 or 232 or 300 bar DIN tank valve. No problem at all. I do it all the time.

Much of the discussion has and will focus upon SHOULD you and is it IDEAL and what valve SHOULD you get on your tanks, but you didn't ask that question now did you?

 

[Jason B]

it's done that way so that the "weaker" 232 fitting is not subjected to the "stronger" 300 pressure

Just to clear up a few things....the 200bar valve is not weaker then the 300bar. The extra threads provide no extra strength, they just prevent you from using a low pressure first stage on a high pressure tank.

Is a 300 bar SCUBA valve outlet stronger than 200 bar? No, they are equally strong. Only the first few threads in both the 200 bar and 300 bar outlet designs are doing the work, the remaining threads on the 300 bar outlet are there simply to create a deliberate incompatibility with a 200 bar connector. In fact, in practice, the 300 bar valve outlet has proven itself to be more fragile than the 200 bar valve outlet. The 300 bar valve outlet is so long that the smallest 'ding' on the edge of the opening can slightly warp the cylindrical opening, causing the regulator to become difficult or impossible to completely seat. This problem does not seem nearly as pronounced with the 200 bar valve outlets, although it remains an issue and all DIN outlets should be protected from dings.

Taken from here...
http://www.diveriteexpress.com/library/valves.shtml

 

[Meng_Tze]

To be pedantic/nit picking.....
That statement is technically wrong.

The screw trhead is a uniform thread and thus screwing in 7 or 9 threads will devide the force of the pressure over 7 or 9 threads. At a higher pressure than rated, the 7 thread connection will come to breaking point earlier than the 9 thread. So looking at it mechanically, yes a screw thread connection with more threads is capable of holding larger forces that one with less given equal materials and screw thread.

But I am nit picking....

 

[texdiveguy]

To be pedantic/nit picking.....
That statement is technically wrong.

The screw trhead is a uniform thread and thus screwing in 7 or 9 threads will devide the force of the pressure over 7 or 9 threads. At a higher pressure than rated, the 7 thread connection will come to breaking point earlier than the 9 thread. So looking at it mechanically, yes a screw thread connection with more threads is capable of holding larger forces that one with less given equal materials and screw thread.

But I am nit picking....

Just my point from my earlier statement.....very little differnce. It is a 'good thing' to nit pick at times.

 

[H2Andy]

Just to clear up a few things....the 200bar valve is not weaker then the 300bar. The extra threads provide no extra strength, they just prevent you from using a low pressure first stage on a high pressure tank.

hence my use of quotes around the words "weaker" and "stronger." i couldn't quite figure out how to express the concept of low pressure valves and high pressure valves quickly.

however, technically speaking, a low pressure regulator is "weaker" than a high pressure valve, and so putting a "weaker" regulator into a "stronger" valve will
lead to problems... which is why they make it impossible to do that in the first place

what you're talking about is whether a low-low combo, a high-low combo, or a high-high combo are structuraly stronger or weaker than each other ... not really .... maybe just a wee bit, but not much, certainly not enough to be significant (note that you can't have a low-high combo, since the 232 bar reg won't fit into a 300 bar valve)