No gas flow through regulator

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Aidan Cookson
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No gas flow through regulator

Post by Aidan Cookson » Sat Aug 09, 2014 10:30 pm

When I open the valve on the bottle of deuterium, it leaks out, and the regulator works fine with an air compressor. However, when I put the two together there is no flow at all through the system. Has this ever happened to anyone? My only guess is that the pressure is too high for the regulator, but I don't see that stopping the flow completely. I have a restek mini regulator 0-15 output and I got the gas from Cambridge isotopes.

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Rich Feldman
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Re: No gas flow through regulator

Post by Rich Feldman » Sun Aug 10, 2014 2:34 am

I hope your regulator isn't like this one: http://www.restek.com/catalog/view/3558/22032
which is rated for a maximum input pressure of 300 psig. Yes, three hundred.
The much higher pressure in your D2 bottle could be too high for the regulator to work,
not to mention the risk of bursting something in the regulator.
Did you have to change the high-pressure nipple to fit your cylinder?
That's a huge no-no.
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Richard Hull
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Re: No gas flow through regulator

Post by Richard Hull » Sun Aug 10, 2014 5:10 am

The pressures in a new lecture bottle vary but 1000 psi is a minimum and I don't think there is more than 2000 psi in the more large content lecture bottles. You really need a hydrogen pressure regulator gauge set. I had mine made up to order from a gauge company recommended by Carl Willis a few years back. Cost under $150 back then. Gas handling is one of those technologies you are supposed to read up on!

Read and heed the FAQ! You should had done this already!

viewtopic.php?f=24&t=2784

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
Retired now...Doing only what I want and not what I should...every day is a saturday.

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Chris Bradley
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Re: No gas flow through regulator

Post by Chris Bradley » Mon Aug 11, 2014 11:25 am

Without wanting to contradict the previous posts, I would point out that we, amateurs, may well need to perform all sorts of bodging and other less desirable practices with the equipment available to us at the prices we are prepared to pay.

It is possible to use lower pressure components in the gas line, but one must, obviously, be very cautious. I routinely use 15 bar components in the stream of my 100 bar bottle. The way I do this is, with great care, open and close the bottle valve only slightly and momentarily. With care you can happily vent 10 bar into the volume between the bottle and regulator, and then close the bottle valve again.

I would never run my system with the bottle open. This is simply because it is totally unnecessary. There is, I'd estimate, around 12cc volume between bottle and regulator so by putting 10 bar in there I have 120 standard cc. This is more than enough for several experiments and there is no risk whatsoever of any lines becoming leaky or detached as the actual bottle is then closed at all times.

Further, it is also a means to calculate overall usage. Each time I use 120cc worth of gas, I can deduct it from the 50 litre total and know how much I have left. I also mentally reduce that quantity down to a cost value for the test sequence, until I 'refill' the regulator volume, so I know how much each experiment is costing me in D2 (usually peanuts, overall).

In regards regulators, I would also advise that folks pay attention to whether the regulator can sustain a vacuum. It is desirable to evacuate your line to the regulator and the volume between it and the bottle. Some can be evacuated in that way, but some will get damaged by the process.

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Richard Hull
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Re: No gas flow through regulator

Post by Richard Hull » Mon Aug 11, 2014 4:15 pm

I have a formal regulator with the low pressure gauge set for 2 PSI. As I barely crack the D2 bottle vlave and see the 2 psi gauge react, I send this puff of gas to a small used CO2 cartridge as an experimental reservoir in my gas line. I immediately turn the bottle gas off. I do not even allow the high pressure gauge to fill to indicate bottle pressure. It is an artform. I have never, ever run my system, deuterium bottle open!

My average bottle of 50 liters lasts 5 years. The empty CO2 cartridge allows about a 1-2 hour run time at lower fusion levels. When I can up the running flow pressure to over 10 microns in large fusion runs, I get a bit less than an hour. I monitor the 2 PSI line gauge during major timed runs. I can refill the cartridge on the fly during a run and get that 2 psi back to full status by recracking the bottle valve. This is the value of a normal, formal regulator set of gauges.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
Retired now...Doing only what I want and not what I should...every day is a saturday.

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