Hi Everyone,
Has anyone else tried to use metal sheathed teflon hose
for the oil return pipe under the Rotax?.
Following the thread on the web site, I decided to try
and source some suitable hose and found some that sounded just right [ spec.
to 232Deg C.,
103Bar operating pressure] at a local Aeroquip supplier. This has to be
swaged onto the fittings at each end, so they tried to source fittings that
matched the Rotax ones, but with limited success. Although the threads
matched, they were for higher pressure applications, so the walls were
thicker resulting in a smaller bore.
In the end I got them to swage the teflon hose onto my
supplied fittings, and it looked good. There were two problems though.
Firstly the hose won't twist at all, so the angles of the fittings have to
be very accurately set before swageing. Secondly the hose is quite stiff
and although the min bend radius is quoted as 165mm, which should be tight
enough, the hose tends to go quite lumpy and out of shape as it is fed
through the tight spaces. These lumps and and slight kinks don't go away
when the hose is straightened.
Does anyone know if this is likely to be a problem under
the temperatures and pressures of normal operation?. Is it going to get
worse with the vibration?. Is the flow going to be at all restricted?
Many Thanks,
Paddy Clarke # 404
|