Liquid Ring Vacuum Pumps?

Anyone have experience rebuilding one of these?

I've been using a 3hp refridgeration compressor which doesn't really want to go over 21inHg but apparently the liquid ring pumps working with oil will pull 29inHg pretty easily.

The rebuilding part comes because I bought a 5hp liquid ring pump several years ago, third hand, mostly for the tank and the motor controls. Some bright spark put the whole thing into storage with about three inches of water in the pump, and I've just taken it apart to survey the damage.

It looks like a fairly straight-forward job to machine the four plates that face against the two impellors. The rings around the impellors will also need to be machined, and re-lined to match the impellors. The rest of the rust I can take off with my die grinder and scotch-brite pads.

Questions is: how tight do the tolerances have to be? I'm going to get a local shop to do the machining and do everything else myself, but I don't want to get everything back together and find it's too tight to turn or too loose to pull a good vacuum. My inclination is to go with a standard turned finish on the lathe without any further work.

Any help would be appreciated.

Regards,

Matt Turner
Turner Racing Shells Ltd.

 

Matt, I spent nearly 20 years in vacuum technology, but never ran across one of these, tho I am aware of them. Believe it or not, water is quite commonly used as their working fluid, but if lower ultimate pressures are needed, a suitable vacuum pump oil would be used in place of water.

I'm attempting to contact various parties to see if I can further assist. So far no one has been able to help me with respect to your question. One question that has already come up - what is it? Who made it? Single or dual stage? Do you have the model number?

No promises here, but I'll see what I can uncover.

 

Matt, I'm sorry that this took so long... I haven't really found out anything earth shattering. He whom I felt would be your best hope also ain't laid eyes on one.

Best guess: Clean up the bits, put it together, and see what happens. His best guess is that tolerances can't be all that significant.

I'm going to keep poking to see what else I can find out for you.

 

I have been trying to learn all I can on vaccum bagging? I've got the basics but can anybody go into detail? Thanks - Ricki

 

It sounds like you have a flat sided 2 stage pump, the clearances should be about .005-.007 per side. You can contact us at www.liquid-ring.net tour our site and if we can help, give us a call