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02-21-2012, 05:03 PM #1
large vacuum fittings flanges where to find
We are building a vacuum chamber for helium leak detecting.
I need to find some large vacuum fittings like flanges and quick connecting clamps and so forth.
Have the ability to make, weld, machine whatever we can but would rather buy if available. Our chamber will be made from a tube that will be about 11.5" in diameter OD.
Is there anywhere I can buy clamps and so forth that big?
02-21-2012, 05:19 PM #2
02-21-2012, 05:23 PM #3
02-21-2012, 05:54 PM #4
Kurt J. Lesker is another company that sells vacuum fittings.
02-21-2012, 06:36 PM #5
MDC Vacuum Products Corp.
02-21-2012, 08:09 PM #6
Just curious. Why do you need a chamber a foot in diameter to build a leak checker?
02-21-2012, 08:23 PM #7
it goes like this
we build Stirling engines. They are pressurized with Helium which is the working fluid of the gizmo and also what is necessary for the leak checking helium sniffer apparatus.
So once we build the machine, weld it shut, pressurize with helium drop into vacuum chamber and this gives a leak check of our machine or pressure vessel, however you want to look at it.
This particular machine with its mounting features needs about a 11" ID cylinder to fit into.
07-18-2012, 07:21 PM #8
07-18-2012, 08:02 PM #9
Used to be a place in Salem MA, McGraths, that sold lots of used vacuum equipment - they may still be around. Companies like Varian and Huntington also sell vacuum fittings as well as those already mentioned. The stuff is not cheap when buying it new. I have a bunch of it that I took to the local tool seller so he could put it on eBay for me and I don't think he has sold it yet. I'll check with them and let you know. There was a bunch of QD fittings and flanges in the pile.
07-18-2012, 09:24 PM #10
"we build Stirling engines. They are pressurized with Helium which is the working fluid of the gizmo and also what is necessary for the leak checking helium sniffer apparatus."
Um. The usual approach to this is to evacuate the engine with the vacuum pump you use before backfilling with helium. Put your
leak checker on the *internals* of your engine via that fill port.
Then spray the exerior of the engine with tracer gas (helium) to check for any leaks and pinpoint their exact location for repair.
If you want a simpler test, bag the engine with a plastic bag and fill that with helium to 'bomb' the system.
But the ability to localize leaks with a small helium probe is invaluable.
If you really really need to enclose the entire engine, get an aluminum can with welded bottom, O-ring seal. Seal that
to a flat plate that is ported to the leak detector test connection.
But I advise the simpler approach.
07-18-2012, 11:01 PM #11
The leakcheckers I've seen can also be used with a probe that detects helium leaking out.
Same as the inboard test but you pressurize with helium.
The inboard test is far more accurate I think.
For the 10k or so you will spend on this chamber, you can buy a nice leak checker, albeit used.