Heidolph Vacuum Switchbox - Manual (Page 64)

64
E
Replace diaphragm:
Loosen diaphragm back-up disc with special tool.
Check for shims; arrange shims by cylinder and re-install
same number of shims.
¾
Insufficient number of shims: pump won't be able to
reach final pressure; too many shims: pump running
noisy.
Install new diaphragm between back-up disc with square-
head bolt and back-up ring.
¾
Caution: light-colored side of diaphragm points
towards cocking disc.
Install cocking disc, diaphragm, and back-up ring with
piston rod; use special tool.
¾
Make sure square-head bolt is properly seated in the cut-out of back-up ring.
Install pump heads:
Turn eccenter until piston rod reaches a position that
allows diaphragm to be located in the center of the
diaphragm and smoothly on mating surface of the
housing's cut-out.
Reverse above sequence of operations for assembly.
Install cover, valves and inside part of lid and cover.
¾
Make sure to install valves the right way.
Turn eccenter until piston rod reaches upper dead center.
¾
Max. piston rod stroke.
¾ Pull 4 ea. hex-recessed straight screws diagonally
(hand-tight) (e.g. in the following sequence ←, ↑, →,
↓) , thereafter torque to 10 Nm.
Check serviceability of pump heads
Gauge pressure at intake port.
With an adequate vacuum gauge reading at the intake end
should be less than 90 mbar.
¾
If not, check housing once more. Check correct seating
of valves and diaphragms (in-line with hole in housing).