For reference I have a 12 zone system that I blow out in the fall with my 10
CFM @ 90 PSI compressor. It is marginal to do the job. It takes me all day
because I allow the compressor to cool down between each zone. The
compressor is 5 HP and has a 33 gal tank but is not rated for continuous
duty. Boy does it get hot.


Secret wrote in message
. 97.131...
"Chris Shearer Cooper" wrote in
:

How do I know if the compressor I bought to power my finish nailer is
strong enough to blow out my brother's sprinkler system?

It's just a little pancake compressor (Porter Cable, 6 gallon tank),
it says it can do 3.7 cfm at 40 psi or 2.6 cfm at 90 psi, but I'm
thinking those are continuous numbers? And I need like 10 cfm but
only for like 30 seconds?

Thanks!
Chris

p.s. More proof there are too many lawyers ... the owner's manual
includes, in the hazard section, a warning that if you put it on a
table/workbench/roof, it might fall off and hurt you. Duh!



It's not. There is a reason that the lawn service guys use those huge
compressors. The smaller ones will provide the pressure but not the
volume necesarry to clear the lines. What will happen if you use on of
these is that most of the water will clear, but you will still ahve water
pooled in the lowest parts of the lines. If your lines are deep enough
(they almost never are) to avoid freezing then it doesn't matter, but
otherwise you will find ruptured lines in the spring when you turn the
water back on.
In a previous life I did lawn sprinkler installations and every spring
we would do dozens of repair calls on systems where homeowners had
attempted this. You also have the problem of how to connect your hose to
the blowout. In any event, it is probably not worth the trouble or risk
to save the $40.00 or so that the sprinker guy charges.