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  1. #1
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    Pulling a vac through a manifold/digital

    So I get the reason for using a crt and the removal of the core but my confusion is with all the controversy over everyone saying you shouldn’t use a manifold to pull a vacuum. Why are manufacturers incorporating a micron gauge into their manifold along with the 4th port if it’s not a wise practice. Like on the new Sman-480v

  2. #2
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    Using a 1/4″ hose chokes the vacuum pump—no matter how big—down to about 0.5 CFM at 1,000 microns. Your gauges and standard hoses will also leak under a high vacuum. Testo uses a external micron gauge on some of there digital sets.

    Sent from my SM-G960U using Tapatalk

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  4. #3
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    Quote Originally Posted by Jlstan View Post
    So I get the reason for using a crt and the removal of the core but my confusion is with all the controversy over everyone saying you shouldn’t use a manifold to pull a vacuum. Why are manufacturers incorporating a micron gauge into their manifold along with the 4th port if it’s not a wise practice. Like on the new Sman-480v
    If I had to guess - it's because it's a value-adding feature that was able to increase the price point as well as demand for their product.

    Sent from my Moto Z (2) using Tapatalk

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  6. #4
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    So why not use 3/8 inch vacuum rated hoses on the manifold?

  7. #5
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    It will work, but but I believe it comes down to best practice. If you blank your system off to test your vacuum you will have 10 or so leak points. Isolating your system with a micron gauge on your VCRT or another point on your system will eliminate these points.

    Sent from my SM-G960U using Tapatalk

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  9. #6
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    So blanking off at the CRT using a manifold with 3/8 inch hoses would have more leak points??? The leak points would be no longer with the CRT valve closed. And would only be reading the micron gauge at the CRT port which would be displaying the micron reading on the digital manifold gauge. Using a Testo or Yellow jacket

  10. #7
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    As far as I know the Sman has a internal micron gauge. The testo has a external that would work on the valve core tool.

    Sent from my SM-G960U using Tapatalk

  11. #8
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    Quote Originally Posted by Jlstan View Post
    So blanking off at the CRT using a manifold with 3/8 inch hoses would have more leak points??? The leak points would be no longer with the CRT valve closed. And would only be reading the micron gauge at the CRT port which would be displaying the micron reading on the digital manifold gauge. Using a Testo or Yellow jacket
    You still have all those leak points while pulling the vacuum.

    Your hoses will still have the restriction of the valve core depressors.
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  13. #9
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    I think if you could somehow retrofit a copper line through a T with a micron gauge in the T from the pump to the condenser, this would be the absolute best way with little to no leaks to ever worry about. I don't trust hoses, never have, they will ALL leak eventually, there hoses. If you could somehow coil up the copper, it would help with any vibration that might after a long use cause the flare fittings or whatever fitting you used to deteriorate or crack, but my guess is the copper would last a good long time. Until we get away from hoses, you will eventually always have leaks, again they're hoses with crimp fittings on the ends, plus, just using them to pull vacuums with deterate them all eventually.

    EDIT: Air can also permeate thru rubber hoses under a vacuum.
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  14. #10
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    Agree...
    Quote Originally Posted by Mr Bill View Post
    I think if you could somehow retrofit a copper line through a T with a micron gauge in the T from the pump to the condenser, this would be the absolute best way with little to no leaks to ever worry about. I don't trust hoses, never have, they will ALL leak eventually, there hoses. If you could somehow coil up the copper, it would help with any vibration that might after a long use cause the flare fittings or whatever fitting you used to deteriorate or crack, but my guess is the copper would last a good long time. Until we get away from hoses, you will eventually always have leaks, again they're hoses with crimp fittings on the ends, plus, just using them to pull vacuums with deterate them all eventually.

  15. #11
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    Quote Originally Posted by Jlstan View Post
    So I get the reason for using a crt and the removal of the core but my confusion is with all the controversy over everyone saying you shouldn’t use a manifold to pull a vacuum. Why are manufacturers incorporating a micron gauge into their manifold along with the 4th port if it’s not a wise practice. Like on the new Sman-480v
    Cuz there are still a lot of old timers in the field who are scared of change.
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  16. #12
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    Quote Originally Posted by Jlstan View Post
    So blanking off at the CRT using a manifold with 3/8 inch hoses would have more leak points??? The leak points would be no longer with the CRT valve closed. And would only be reading the micron gauge at the CRT port which would be displaying the micron reading on the digital manifold gauge. Using a Testo or Yellow jacket
    I'm one of those almost "old timers" I mentioned above. I can't tell you how many times I tried pulling a vacuum back in the day on a system and cant get it to pull down below 1000. Now you have to figure out if your gauges, hoses, valves, etc are leaking or the system itself. It will drive you nuts. The least amount of potential leak points you have the better while pulling a vacuum. It's not just the increased speed from pulling with something like two sets of Appion Megaflow kits.

    I can say switching to two Megaflow kits from evacuating though a manifold is the best tool purchase I've made. I'm actually contemplating the $650 TruBlu set up.
    “Free men do not ask permission to bear arms.”
    -Possibly said by Thomas Jefferson(but true even if he didn't)


    “What one generation tolerates, the next generation will embrace.”
    ― Definitely said by John Wesley

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  18. #13
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    I totally understand the reducing the leak point thing and having as few connections as possible. I just find it odd that manufacturers still are pushing evacuation systems using the manifold if it were a huge problem regarding leaks. Like the 4 valve manifolds and the Appion Mega flow kit.
    Quote Originally Posted by Brian8383 View Post
    I'm one of those almost "old timers" I mentioned above. I can't tell you how many times I tried pulling a vacuum back in the day on a system and cant get it to pull down below 1000. Now you have to figure out if your gauges, hoses, valves, etc are leaking or the system itself. It will drive you nuts. The least amount of potential leak points you have the better while pulling a vacuum. It's not just the increased speed from pulling with something like two sets of Appion Megaflow kits.

    I can say switching to two Megaflow kits from evacuating though a manifold is the best tool purchase I've made. I'm actually contemplating the $650 TruBlu set up.

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