On Sun, 30 May 2004 17:33:39 GMT, Ted Edwards
wrote:

larsen-tools wrote:

I read somewhere that it's not a good idea to uses Teflon tape on threaded
joints in a hydraulic system.

As I understand it, the TFE "problem" is fine shreds of TFE getting into
the system snd clogging fine jets (e.g. diesel injectors). If properly
applied to pipe threads, it's fine. "Properly applied" means the tape
does not cover or extend beyond the last male thread. I think the
"don't use" mandate is because you can't count on the ham fisted
properly applying it.

Ted


I once set up a hydraulic system to drive a very small servo valve
controlling a roller position within very few thousandths. Tiny
orifices in that thing, and it was very expensive. The plumbing was
mostly mechanical tubing, with very few tapered thread fittings. We
used a hardening Loctite product designed to seal hydraulic systems on
those. The servo valve, manifold mounted, came with a flushing
fitting to allow startup and circulation through the filters for a day
before changing the filters and installing the valve. The
commissioning instructions were full of cautions about maintaining
near clean-room conditions while the system was open.

I suspect there'd be a lot more forgiveness in hydraulics on a backhoe
or something similar.

Pete Keillor