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  1. #14
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    Hold up...
    You still connected to the tank valve?
    I though you were talking about ⅜ connections on whatever was getting evacuated...

  2. #15
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    Quote Originally Posted by itsiceman View Post
    Hold up...
    You still connected to the tank valve?
    I though you were talking about ⅜ connections on whatever was getting evacuated...
    Yes I am. This recovery cylinder has 2 drum adaptor connections instead of 1/4” flare connections. I used a 3/8 drum adaptor for the 3/8 hose and a 1/4 drum adaptor for the half inch hose. Hooked another 1/4” drum adaptor and my micron guage up to the liquid port.

  3. #16
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    I don't know enough about the valve internals. Was thinking about it differently. I was thinking about hooking up to the shut-off float connection on my tank just to see. Looks like a ¾ pipe thread and was gonna use a ¾ to 1" hose and see if I could clear the 30# tank in less than a min. for academic s+g's Lol

  4. #17
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    That’s a pretty unscientific test with widely relative results.

    If you have a tank at 760,000 microns, pull to 500, you removed moisture, etc. that was keep you from getting to 500.

    Now you connect to the same tank, and pull it down again. You’re gonna get there faster the second time regardless of hose size.

  5. #18
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    Quote Originally Posted by 71CHOPS View Post
    That’s a pretty unscientific test with widely relative results.

    If you have a tank at 760,000 microns, pull to 500, you removed moisture, etc. that was keep you from getting to 500.

    Now you connect to the same tank, and pull it down again. You’re gonna get there faster the second time regardless of hose size.
    I saved a lot of the procedure out because I didn’t feel like typing it out. I first evacuated the tank to 199 microns. Then I left it open to atmosphere for 5 minutes. I closed the cylinder valve and blanked off pump to cylinder, and ran pump to 50 microns. Then I opened the cylinder valve and timed how long to 500 microns. First with the 1/2” hose. 10 minutes 45 seconds. I followed this exact procedure with the 3/8 hose, 15 minutes and 20 seconds. I switched back and followed this procedure with 1/2” hose again, 10 minutes 43 seconds. It was late and I was out of time to do 3/8 again but with results that close on the 1/2” hose I am personally satisfied that the larger hose is faster and that most likely I would get a similar result with 3/8 to the first trial. Not a scientist, but enough to convince me which hoses to use, even given the option of a 3/8 flare connection to the system.

  6. #19
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    Quote Originally Posted by 71CHOPS View Post
    That’s a pretty unscientific test with widely relative results.

    If you have a tank at 760,000 microns, pull to 500, you removed moisture, etc. that was keep you from getting to 500.

    Now you connect to the same tank, and pull it down again. You’re gonna get there faster the second time regardless of hose size.
    I actually used the 3/8 hose on the second trial so I got there slower than on the first trial.

  7. #20
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    Would like to see a ⅜ x ¼ hose any size pull a tank from a ⅜ straight through fitting vs a similar ¼ fitting. Would like to see the same hose used just change the direction.
    ⅜ on tank ¼ on pump vs ¼ on tank and ⅜ on the pump.

  8. #21
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    Quote Originally Posted by itsiceman View Post
    Would like to see a ⅜ x ¼ hose any size pull a tank from a ⅜ straight through fitting vs a similar ¼ fitting. Would like to see the same hose used just change the direction.
    ⅜ on tank ¼ on pump vs ¼ on tank and ⅜ on the pump.
    Absolutely! Great ideas. I would do it but I have a stomach bug and am not feeling up to it. I’m starting to think this is a matter of adding all restrictions together in series? So reversing the hose wouldn’t change anything? Rather curious about it though, it’s usually the opposite of what I think it is. Ha.
    Mind you, I do have to pull this vacuum one more time since I didn’t put a holding charge into the cylinder yet.

  9. #22
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    I believe it would be faster pulling with ⅜ on the tank. By how much IDK.

  10. #23
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    What's the CFM rating on your pump?

  11. #24
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    Micron gauge on the liquid port of a 30# tank
    One 1" hose connected to the ¾" float connection one 1" hose to the ¼ vapor valve on the tank. 7 CFM pump.
    Pulled 200 microns in 2:00 and it's 83% RH



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    “If You Can Dodge A Wrench You Can Dodge A Ball”

  12. #25
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    Quote Originally Posted by itsiceman View Post
    Micron gauge on the liquid port of a 30# tank
    One 1" hose connected to the ¾" float connection one 1" hose to the ¼ vapor valve on the tank. 7 CFM pump.
    Pulled 200 microns in 2:00 and it's 83% RH



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    7 cfm, got a 10 platinum coming from eBay, read all the stuff about pump cfm, we do enough centrifugal that it’s really hard on the 7’s unless we throttle them, got it super cheap, see how the 10 does.

    I wonder if your hoses are at a point that any larger and you wouldn’t see much or any gain without a bigger pump? Also wonder how big you can go before a 1/4” flare fitting on a tank stops you from going any faster. I like what you’re doing though, that’s crazy how fast you are going!

  13. #26
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    1/2" vacuum lines 6 feet long can move 5.5cfm at 1000 microns.

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