Balanced Siglestage regulators.

[smurf]

Hi, I owne two old twohose regulators. A spirrotechnique Mistral and a spirrotechnique Royal Mistral. I asked someone what the big difference is between them and he said that te Royal mistral is a balanced single stage and the mistral an unbalanced. Now my question is what is the difference in function?

thanks,smurf

 

[Diver0001]

smurf once bubbled...
Hi, I owne two old twohose regulators. A spirrotechnique Mistral and a spirrotechnique Royal Mistral. I asked someone what the big difference is between them and he said that te Royal mistral is a balanced single stage and the mistral an unbalanced. Now my question is what is the difference in function?

thanks,smurf

If he's right, which I can't confirm, then one of your regulators is probably pneumatically balanced for tank pressure the way most, if not all, modern regs are. If this is true then it would have been quite an innovation at the time. Mechanically, it probably uses a slightly lighter spring to close the valve and it might breath a little easier, especially at low tank pressures.

In any event take my advice and upgrade.

R..

 

[smurf]

I onely dive with them sporadic. I just wanted to know what the difference was.

 

[rag]

I always thought that the only difference is that Royal Mistral has one-way valves in the mouthpiece and the old Mistral hasn't. Plus a remodeled case. But then again, I've never dived either one of
them. yet..

http://www.wttfw.freesurf.fr/article/article.php?langue=uk

check out "Standard Mistral regulator diagram",
"Royal Mistral regulator diagram" and "Functionality principe of the Royal Mistral". The working parts seem all the same to me.

 

[oxyhacker]

I think the Royal Mistral never made it to the US. It was just a modified Mistral single stage unbalanced reg.

In the US,we had the Mistral variants, which were single stage and unbalanced, then the Aquamaster, which was two stage, and the Royal Aquamaster, which was two stages and balanced, and was considered quite the thing in its day. As result, a lot of Americans assume the "Royal" must mean balanced.

There's a schematic for the RM at:
http://www.sea-cruise.net/royal_mistral.htm
where you can see quite clearly that the demand valve is the same as on the other Mistrals.

Neat reg!

smurf once bubbled...
Hi, I owne two old twohose regulators. A spirrotechnique Mistral and a spirrotechnique Royal Mistral. I asked someone what the big difference is between them and he said that te Royal mistral is a balanced single stage and the mistral an unbalanced. Now my question is what is the difference in function?

thanks,smurf