Vacuum Pumps

jerryb

Would or could somebody refresh my poor memory about " Vacuum Pumps" Have a wing of a school that has a combo vacuum condensate receiver.One pump for condensate the other for vacuum.The question is,how many inches of vacuum should this unit run at???? An answer from the many steam wizard's would save me some time going thru the old dusty books!Thanks Guy's

[Deleted User]

vacuum

3"-8" seem to work well in the schools I work in.

jerryb

Thanks Mike.

Unknown

Well,

Depends on what type of system it is on. Obviously, it's a 2 piper. If the pipes on the returns are undersized for gravity, then you need the vacuum to reach all the way to the farthest radiators.

If it's a Vari-Vac, it could be a regular 2 piper that had vacuum added with the retrofit, assuming that it didn't go in as a Vari-vac system. Then you could run it at any vacuum, right up to none at all.

If it got added to hide bad traps or water in the returns that hinder venting, then, I guess each of these are different. Evaluate it that way.

The clue will be the sizes of the returns, and the load connected to them.

The vacuum won't lower the BTUH consumption, won't lower the steam pressure, won't suck water through plugged returns, and won't hide failed traps for very long. The seal in the pump will fry. Over and over.

It will help where the returns are undersized by design for vacuum (to save steel).

I had a dual pump unit that I ran at: both pumps to 7" and one pump to 14". Off below that (or above that, if you read higher vacuum as above).

It didn't matter a bit, because it was a 1910 system, 4 stories, with gravity returns. I could have ran it without vacuum.

http://www.mepcollc.com/VV.htm#mepco2

Noel