OP-755 Part 2 Pages 197-401 - Personal Page of GENE SLOVER

366
The tinning of male threads of fi ttings gives a hydraulic connection
superior to a connection made with sealing compounds.
Such compounds should not be used when tinning is possible.
Sealing sleeve s must be sea ted with careful ini tial alignment,
with the connection drawn-up evenly and without canting. A
distorted or marred sleeve will leak, may produce a burr as
it seats.
7. When fittings have been newly secured to pipes
(particularly flanges) they should be given a hydrostatic test
at a pressure substantially higher than that to which they
will be subjected in service.
8. Tubing must be accurately bent and fitted so that
it will not be necessary to spring it into place.
High pressure tubing which has length greater than 100 diameters
between fittings, and particularly those pipes which are
subject to rapid variations of pressure, must have pipe clamp,
or bracket, or other similar. support adjacent to each bend ~
Vibra tion .in such tubing will affec t the uniform smooth operatiOn
of the system and will cause crystallization at the terminal
fittings.
9. When a new unit or an overhauled unit has been assembled
into a system (or if a new or replacement pipe or pipe
fi tting has been installed), fill the sys tern wi-th the pr-escr i bed
hydraulic oil, using a 120 mesh screened f'unne L> (never use
cloth for filter~ng), and draw off the oil at the drain point
through ~'second filtering screen. Observe the latter screen
and continue flushing until assured that the system is clean.
Draw off oil and pass it through a Briggs clarifier, close the
drain aperture and refill according to the routine prescribed
for the particular system.
Do not operate the unit when flushing to remove foreign matter.
10. Whena new or overhauled replacement unit has been.
ins taIled in a system and has been flushed clean as prescri bed
above and has been refilled with fresh oil or clarified oil,
set all controls on neutral and start the electric motor. Build
up response pressure and for ten minutes permit such circulation
to take pLace as will occur with controls at neutral.
This circuia tion will be small, comprising in most systems the
oil leakage through valve block ports and past valve surfaces.
However it is an important effort to remove particles at or
near contact surfaces which otherwise might produce scoring.
It is essential that no valves or other parts having very fine
clearances be moved even the slightest amount until the system
is as clean as it is possible to make it.
* For receiver regulator systems use a 200 mesh screened funnel.