John wrote:

Lee Nowell wrote in
:

I had assumed that the pipe had to be all the way in to exert the nut
tightening force in the olive.


By backing off slightly, the tightning force will be applied to both sides
of the olive. If the pipe is pushed all the way in then there is no
movement possible at the inner end so nearly all the final
deformation will be at the outer end of the olive. Think it through for
yourself and see if you agree.


And especially likely to catch you out if you use the same nut and olive
on a new fitting (e.g. radiator valve) with a slightly shallower pipe
recess; without excessive deforming force the side of the olive away
from the nut will be held away ffrom the fitting by the length of the
pipe. The remedy is to take mm or two off the end of the pitpe, but
that is a nuisance.

--

Roger Hayter