Fusor Forums

Just wondering what kind of plumbing, valves, etc., do you use to test the vacuum pressure your pump can pull at the head. I am worried that if I do it wrong, oil will back flow and mess my transducer for good.

Thanks!

Any thing wrong with reading the FAQs in this vacuum forum.... like this one!

viewtopic.php?f=25&t=4060

Sometimes I wonder why I bother to write these.

Richard Hull

So that you have a link to post when the question shows up again.

I had to go find the link. I did not have to go and give it to him. He should have read the FAQs and his question would have been answered. In future I may or may not take the time to help out with a link as I have already helped out in 2010 by writing the extensive and helpful FAQ. It is up to the newbie to use this valuable source of data already in place to avoid needless questions answered over and over, ad infinitum.

"I am not here to spoon feed you people" as one of my old college professors yelled out to my class on a regular basis. It was a different world then when students in search of knowledge were forced, against their will, to seek out knowledge via reading their texts and hitting the library. It is what college training is all about, in theory. The library and text here are the FAQs!

Richard Hull

I had already read that FAQ, it is very valuable. But what I mean is how to connect a vacuum transducer direectly to the pump? The FAQ says that you should use a short 6 inch hose, but my question is mainly fuquosed as to if I should use a valve between the pump and the vacuum sensor, in order to avoid any oil into the electronics of it.

Sorry if I didn't explain myself, or if this is to obvious.

You can use a valve inline or a vacuum relief valve in line or, as suggested in the FAQ, just pull the hose off or uncouple or remove the gauge at pump stop. Anything to avoid suck back. Do not rely on an auto-functioning suck back valve included in many pumps. Just another point of failure. The obvious course is, do whatever it takes to avoid having oil roll back up the line. there are four or five solutions here. Pick one. The cheapest is just pull the line off the pump or pop off the gauge at shutdown, killing the vacuum. Pretty much a no brainer.

Richard Hull

Thanks Richard, I was just very nervous of killing my transducer. Since this thread doesn't add anything to the forum, I would like if it could be deleted.

Thanks!

We do not delete honest threads that might help others. We only throw out the trash.

Richard Hull

Richard Hull wrote:... Do not rely on an auto-functioning suck back valve included in many pumps. Just another point of failure. ...

I second that. And still I had to learn that the hard way when I first had a vacuum pump and a pirani gauge and forgot about this. A pirani full of oil is pretty much done for.