Envirosafe

[George Selby]

At 12:25 PM 10/28/2008, you wrote:
>A home style compressor is pretty useless for this.  I have a similar
>venturi unit, and it only pulls a decent vacuum on a BIG industrial
>compressor.  Also good to keep in mind that the compressor will be
>running constantly for the half hour of so it takes to establish a decent
>vacuum.

I have the same type unit, and it works OK for me on a 4HP 
compressor.  It is really useful to see if you have any leaks (pull 
it as low as it will go, then close the valves and see if it holds 
vacuum.    By pulling the vacuum in about 3 stages, allowing the 
compressor to recover in between stages, I can get the vacuum down to 
within a pound of the specs, which has always worked for me.  The 
biggest problem I have is moisture starts accumulating inside the 
venturi device where the air from the compressor comes out, and this 
starts interfering with the pulling of the vacuum.  So I would 
recommend having a moisture trap on the line from the 
compressor.   One final note - it is very loud.  If you have nearby 
neighbors, the combination of the air compressor running contantly 
and air coming out at full speed is quite obnoxious.

George Selby