On Mon, 30 Apr 2007 14:28:46 GMT, "Leon"
wrote:


"Dave Hall" wrote in message
.. .


A shop vac should "suck more" than a DC, if we are talking actual
suction. The DC should move MUCH more air. There is a difference. Kind
of like a garden hose with 50 PSI of water vs. a firemans hose with 5
PSI. The garden hose will put out water at more pressure and would be
my choice for washing the car, but the fireman's hose will put out
more water volume and would be my choice for filling a swimming pool.

Dave Hall

Are yuh shure bout that 5 psi on a fire hose??? It takes pressure to shoot
a stream of water a hundred feet.


I wasn't trying to say that a fireman's hose would only have 5 PSI. In
fact if I am not mistaken a fire hose attached off the same main as a
garden hose will have the same water pressure in PSI as long as the
line it is attached to is at least as big as the hose. The analogy
that I was trying to create was if you had a small water hose in a
high pressure environment it would be great for a pressure use like
washing the car (BTW I certainly would not want to wash my car with a
fire hose at 50 PSI). If you are in a low pressure environment a fire
hose will still move lots of water which is nice for filling the pool.
Obviously this is not a perfect analogy for a number of reasons, not
the least of which is that air and water systems are not comparable,
but I find it the best way that I have been able to get the basic
concept of a DC vs. a vac across to folks who don't want to read some
200 page treatise on dust collection theories and have never actually
worked with a DC. For most people the DC volume vs. the vacs
"sucktion" is a foreign concept.

Dave Hall