Vacum pump question

[Donny Lawson]

A friend of mine called me the other day and said he has a vacum pump that might work with my lathe.It was given to him and he said he really don't have any use for it right now.He asked me to check it out and see if I could use it. The brand and model was a "Welch 1402". I did a google search and those things are over $2700.00 new.Can anyone tell me anything about this pump and would it work on a Delta Midi lathe?If it will work he said I could use it for as long as I wanted it.My friend doesn't have a lathe so it might be something I can use.What's your opinion?
Donny

[Gary Conklin]

5.6 CFM, as long as the pump is good, it should be more than enough.

[Jerry Marcantel]

at $2700 price tag, this pump should have a large tank, and all kinds of other stuff, and get 5.6 cfm without question..... That's a serious pump..... .... Jerry (in Tucson)

[Steve Schlumpf]

Donny - you may want to do some checking on the actual level of hg that the pump will pull.

I know the specs say it will move 5.6 CFM but it lists the max possible vacuum at 104 torr. When I do the conversion - that comes out to 4.1 hg and I do not believe that is strong enough to be of use. Chances are I am doing something wrong - which is why I would suggest you - or someone knowledgeable in converting pressures - to check it out.

[Paul Atkins]

This is a high vacuum pump not high volume pump. It's used in labs where critical vacuum is needed usually in conjunction with a diffusion pump to get the last few molecules of air out. They are oil bath pumps. Not the requirements for a vacuum chuck, but should work if there are not many leaks. It's 1x10 minus 4 torr.

[Thom Sturgill]

1 Torr = 1mmHg
According to this table to convert Torr to Hg multiple by .03937

so 104 Torr = 4.09 Hg

FWIW Torr is capitalized as its named for an individual.

[Ray Bell]

Having used this pump several times in my career, I would not use one for a vacuum chuck. This is a large, belt driven, oil bath, 220V pump. It is critical to be leak free. If not it will emit oil vapors, and contaminate the oil. You will be constantly checking/changing oil.

[Kim Ford]

I have one as well and would not recommend it for that use, for the reasons stated.

Get a Gast (surplus if you can), they are real workhorses and match up very well with the requirements.