Hi, Pug; I wanted to see what the "oxy hacker" had to say before telling you how to transfer NITROX using a single stage regulator as the demand valve. Lately, I've had problems with people citing obscure sources, definitions and such, so I'm sure you understand. Bygones.
Basically, I don't agree with what the Hacker said. It appears that they have never done this before. I give them credit for being aware of it though. As I said, it's an old trick. There is nothing "fussy" about it and it needn't be restricted to a permanent installation as they implied.
I'm not very good at technical explanations but I can answer your questions. I have done this transfer with each of my two compressors. One is a 5cfm Bauer and the other is a gas portable unit rated 4cfm.
Starting at the compressor; the inlet on my compressor is 1" ID. Looking at the regulator(without hoses), the outlet of the Mistral regulator is 1" ID. I attach a six foot length of 1" ID flexible, clear plastic tubing from the compressor to the regulator. Snug fit.
The regulator is a single stage US Divers Mistral manufactured in 1968. It has a yoke screw which is attached to the tank valve in the normal way except for one detail which I will explain.
Since it is necessary to monitor the pressure in the tank supplying the gas, and since the regulator and valve are not configured to allow this, it is necessary to use a special adapter to connect the SPG. The adapter is an obsolete US Divers product which attaches to the SPG hose and is fitted between the regulator and the valve. Physically, this adapter is brass, about 1 1/2 inches long and has a flat face with an O ring. The adapter has 3/8 thread(used on old SPGs). Note: the adapter will only fit late 60's-early 70's regs with the long yoke. This yoke was installed by the factory at time of manufacture specifically for this purpose.
In simple terms, turn on the tank valve to pressurize the regulator, and fire up the compressor. Pump the residual gas into any approved cylinder. The regulator will function as described through a supply pressure range of 2000-200 psi.
The Mistral regulator, if stored in decent conditions will last almost forever. Check the diaphragm with a flashlight as this part is subject to rapid flexing during the operation. If in doubt, open the regulator case. There is basically one other moving part, the high pressure seat. If it leaks, these may be hard to find but a small leak is of no consequence to your operation.
How did I know to do this originally? That's what old timers do, remember stuff. Before it was adapted for diving, the two hose regulator was used to feed natural gas to automobile engines in war time Europe. Gasoline was in short supply.
Why does it work? Because, technically, the Mistral is not a regulator at all, it is a demand valve. As such, the full force of tank pressure is available at all times, instantaneously. This is one reason that Cousteau's team used it exclusively in deep dives. It cannot be "over breathed".
PS: did you read about the Hacker "bag" trick? What a hoot.
Basically, I don't agree with what the Hacker said. It appears that they have never done this before. I give them credit for being aware of it though. As I said, it's an old trick. There is nothing "fussy" about it and it needn't be restricted to a permanent installation as they implied.
I'm not very good at technical explanations but I can answer your questions. I have done this transfer with each of my two compressors. One is a 5cfm Bauer and the other is a gas portable unit rated 4cfm.
Starting at the compressor; the inlet on my compressor is 1" ID. Looking at the regulator(without hoses), the outlet of the Mistral regulator is 1" ID. I attach a six foot length of 1" ID flexible, clear plastic tubing from the compressor to the regulator. Snug fit.
The regulator is a single stage US Divers Mistral manufactured in 1968. It has a yoke screw which is attached to the tank valve in the normal way except for one detail which I will explain.
Since it is necessary to monitor the pressure in the tank supplying the gas, and since the regulator and valve are not configured to allow this, it is necessary to use a special adapter to connect the SPG. The adapter is an obsolete US Divers product which attaches to the SPG hose and is fitted between the regulator and the valve. Physically, this adapter is brass, about 1 1/2 inches long and has a flat face with an O ring. The adapter has 3/8 thread(used on old SPGs). Note: the adapter will only fit late 60's-early 70's regs with the long yoke. This yoke was installed by the factory at time of manufacture specifically for this purpose.
In simple terms, turn on the tank valve to pressurize the regulator, and fire up the compressor. Pump the residual gas into any approved cylinder. The regulator will function as described through a supply pressure range of 2000-200 psi.
The Mistral regulator, if stored in decent conditions will last almost forever. Check the diaphragm with a flashlight as this part is subject to rapid flexing during the operation. If in doubt, open the regulator case. There is basically one other moving part, the high pressure seat. If it leaks, these may be hard to find but a small leak is of no consequence to your operation.
How did I know to do this originally? That's what old timers do, remember stuff. Before it was adapted for diving, the two hose regulator was used to feed natural gas to automobile engines in war time Europe. Gasoline was in short supply.
Why does it work? Because, technically, the Mistral is not a regulator at all, it is a demand valve. As such, the full force of tank pressure is available at all times, instantaneously. This is one reason that Cousteau's team used it exclusively in deep dives. It cannot be "over breathed".
PS: did you read about the Hacker "bag" trick? What a hoot.
