On Tue, 16 Nov 2004 11:44:28 +0000, Andy Dingley
wrote:

On Mon, 15 Nov 2004 21:36:38 -0700, wrote:

home shops never involve anywhere near the volume of dust needed to
generate a hot static discharge into a dust cloud dense enough to
sustain it.

Nor does a commercial DC. It's not the volume that's the issue, it's
the energy per discharge.

dust volume *and* the speed that dust is travelling do have a bearing
on the static charges built up in plastic pipe. high volume + high
speed = large static energy being generated. in systems handling tons
per day like grain silos and millwork factories the risk of static
discharge becomes real. in home shops it's pure unadulterated urban
mythology...





Plastic piping, and unearthed too,
is in regular use for the flexible sections of DC hookups.

that's ABS flex, not long straight sections of PVC

How are machines like panel saws connected to a DC in the USA ? Here
we commonly see ten-twenty foot drops of clear flexible PVC.

and that one machine is unlikely to make enough dust to be a problem.
it's the main trunk lines that do.