Martin Brown wrote:
On 01/04/2012 16:13, Hugo Nebula wrote:
[Default] On Sun, 01 Apr 2012 16:03:42 +0100, a certain chimpanzee,
, randomly hit the keyboard
and wrote:

There's certainly no need for them to shift vast volumes of water to be
effective. I think the point is that they generate (or should do) a very
high pressure by pumping water through a very small orifice. Certainly
my Karcher blasts out a very effective jet, but the actual flow rate is
way less than provided by a mains-fed tap.

So would a hose with a small nozzle not achieve the same effect?

There is a limit to the flow rate through a small nozzle unless you
apply a much larger pressure (ie pump) to the back side of it. People
make terrible mistakes with leaking high pressure hydraulics systems.

A small amount of water carrying a large amount of kinetic energy can do
a lot of damage. I would not use one on my car as I don't want to grit
blast the surface or strip the paint. YMMV Fine for use on dirty patios
though and stone doesn't suffer much from additional scratches.

That's why you vary the distance to the target and the nozzle dimensions.

They are not sandblasters.


--
To people who know nothing, anything is possible.
To people who know too much, it is a sad fact
that they know how little is really possible -
and how hard it is to achieve it.