Could anyone get me a part number for the needle valve that they use for deuterium bleed.
I wonder if anyone has found an "optimum" flow rate for D2; i'd imagine adjusting the flow rate while keeping the pressure pretty constant can be quite a chore for the typical amateur.
Adam Parker
Swagelok needle valves
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Tom Dressel
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- Joined: Fri Jun 22, 2001 4:44 pm
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Re: Swagelok needle valves
Nupro makes two classes of metering valves "M" series or medium leak, and "s" series for fine leaks.
I have a "M" series valve connected to the end of a 24" long, 0.005" ID capillary leak which provides fairly good pressure control. I can keep the pressure at ~5 microns with ease, and actually I have found that, at constant primary voltage, the grid voltage is a very good indicator of chamber pressure. Once the voltage gets to ~4KeV, I ride the voltmeter up to ~8 KeV, by closing the needle valve a little at a time.(the TC gauge will go from ~6 microns to ~4 microns)
Kurt J Lesker sells this valve part #SS-4MG, $153.00 for 1/4" Swagelok, and #SS-4MG-VCR, $217.00 for 1/4" VCR. I found mine, at a vacuum salvage dealer, it came along with the original Hummer V purchase, along with a bunch of other vacuum fittings, CF, KF and VCR.
If I had my choice I would prefer a finer control of pressure possibly with a "S" series valve part #SS-SS4 or SS-SVCR4. Either valve is probably going to require a capillary leak, and none of these valves can be used as shut-off valves (more $$$$$).
I have a "M" series valve connected to the end of a 24" long, 0.005" ID capillary leak which provides fairly good pressure control. I can keep the pressure at ~5 microns with ease, and actually I have found that, at constant primary voltage, the grid voltage is a very good indicator of chamber pressure. Once the voltage gets to ~4KeV, I ride the voltmeter up to ~8 KeV, by closing the needle valve a little at a time.(the TC gauge will go from ~6 microns to ~4 microns)
Kurt J Lesker sells this valve part #SS-4MG, $153.00 for 1/4" Swagelok, and #SS-4MG-VCR, $217.00 for 1/4" VCR. I found mine, at a vacuum salvage dealer, it came along with the original Hummer V purchase, along with a bunch of other vacuum fittings, CF, KF and VCR.
If I had my choice I would prefer a finer control of pressure possibly with a "S" series valve part #SS-SS4 or SS-SVCR4. Either valve is probably going to require a capillary leak, and none of these valves can be used as shut-off valves (more $$$$$).