those "donuts" are, in real life, used for castrating sheep (cheers to
those Australians for finding a second use for everything). however,
they make great tubing clamps. they will crack after a few years
exposure, but are cheap to replace.

the electric wire grommets have nearly no elastic properties.

Ken

In article ,
"01-- Zero One" wrote:

"jcarlyle" wrote in message
oups.com:

Here's a leak testing article that I found helpful:
http://www.borgeltinstruments.com/Leaks.pdf
Sure, it's commercial, but it gives a nice detailed procedure for leak
testing.

Note paragraphs 3 and 4 near the front. Mike recommends using rubber
donuts to prevent leaks (I thinking these donuts are similar to the
grommets used for feeding power cables into metal boxes). He also
concurs with Doug that cable ties or twisted wire are not good for
pneumatic systems.

-John



The donuts he talks about are like "O" rings. Roll them an inch or so
onto the tubing, place the tubing onto the barb then roll the donut back
over the connection. This gives good sealing pressure with no voids.



With good tubing and barbed connectors I have seen precious few leaks
without any sort of clamps. Once the tubing gets hard then, yes, you
could have a leak. If I were going to use any sort of clamps, I would
use donuts.



Larry

"01" USA