H2 Regulator Issues?

[Luke Harrill]

I was leak testing my H2 line and I realized that once I cut my bottle off, the regulator depressureized itself. This valve/vent is what lets the gass out. It is the one with the port and spring on bottom.

Is this proper operation, or do I have another problem on my hands?

-Luke Harrill

[Dennis P Brown]

No expert on regulations though I've used many dozen over the years on all types of system including toxic, reactive, explosive and inert gases; never had a relief valve built in that operated during use for any regulator (though I've had just one regulator diaphragm fail and de-pressurize a tank.) Nor would venting a regulator after a normal fill ever be safe for a hydrogen gas regulator. Now, it could be the over pressure relief valve and if so, likely the regulator had over pressurized in the past and that relief valve is now easy to open. Certainly, I'd never use a flammable/explosive gas with such a regulator that vents explosive gas to the room after use.

[Luke Harrill]

If this is as simple as a pressure relief valve, would it be possible to either tighten the spring or unscrew it and instal a blank?

-Luke Harrill

[ian_krase]

NOOOOOOOO! DO NOT BLOCK SAFETY VALVES! IT DOESN'T HELP!

[Richard Hull]

Carl Willis long ago posted that you must purchase a special regulator for hydrogen gas only or it will leak down. I ordered mine and spent $100, but still have never hooked it up. (typical here in my lab of slothfulness). Thus, I am still using the old adapted victor oxygen welding dual gauge regulator but with a specially installed 0-3 PSI line gauge on the low side. I have used this large, out-sized gauge since 1998.

I have a trick..... I slowly open the main D2 bottle valve and only let in a low pressure of maybe 200- 400 PSIG on the high pressure gauge and then cut off the bottle completely. This means that in the tiny volume of the high pressure gauge I have 200 PSIG of stored D2. The deuterium tank is no longer on line or feeding my gas system. Only the high pressure gauge's "dead volume" is my D2 supply.

I have set the low pressure output regulator for about 1.5 PSIG. This pressurizes a CO2 cartridge tank in the small copper line to that low level. Then I run the fusor like crazy for an hour or two using the bleeder valve in the gas line to feed the fusor.......Slowly, the dead volume of the high pressure gauge yields to the 1.5 PSIG tank and line as I flow gas into the fusor. I note that all the time the high pressure gauge is slowly dropping. I usually end my session when the high pressure gauge is nearing or at 0. If I want to keep going for another hour, I just barely crack the D2 bottle valve, once again, and put a little more in the dead volume of the high pressure gauge and continue until it is exhausted.

A great tip. Never, ever leave your D2 bottle valve open, nor open it all the way. Just crack the valve enough to let in a tiny bit of high pressure gas and use the dead volume of the high pressure gauge as a main high pressure storage tank and put a small tiny back up volume tank on your low pressure gas line as a bit of a buffer.

Just be sure your high pressure gauge doesn't go to zero during a run or your fusion fire will die as the voltage climbs due to light current loading and reduced D2 pressure. I have had this happen and it is easily corrected. All you need to do is just crack the bottle valve again to continue on as before. Note*** Turn your voltage down or off before cracking the valve as the fresh gas pressure may overload your supply or burn out your grid. Just bring the voltage back up normally to your "sweet spot". you may also have to adjust your bleeder fine control valve again.

Again this is a neat little trick to conserve gas and avoid having a high pressure gas leak down over time. Remember, key to the process is a dual gauge system regulator with an ultra low PSI gauge set to a very low gas line pressure and you must have a very small tank in you low pressure gas line as a buffer. ( used an old CO2 cartridge that I silver soldered into the copper line.) You must be mindful all the time of the high pressure gauge reduction in pressure due to gas usage while doing fusion. It is an art....You will get the hang of it.

If you are working at very high pressure leak rates i.e., 30-50 microns as seen in some 2.75 cross fusors you will need to FILL the high pressure gauge all the way to max pressure then cut the tank off, as you are gobbling up your gas in such a fusion system.

I just made this a FAQ in construction and operation forum.

Richard Hull