VACUUBRAND PC 301 - Manual (Page 32)

Documents are only to be used and distributed completely and unchanged. It is strictly the users´ responsibility to check carefully
the validity of this document with respect to his product. Manual-no.: 999147 / 17/06/2014
page 32 of 40
☞ Make sure that the square head screw of the diaphragm
clamping disc is correctly seated in the guide hole of the
diaphragm support disc.
➨ Assemble diaphragm clamping disc, diaphragm and dia-
phragm support disc to connecting rod.
☞ Position washers between diaphragm support disc and
rod.
➨ Lift diaphragm at the side and position carefully together
with diaphragm clamping disc and diaphragm support disc
in the diaphragm key.
☞ Avoid damage of the diaphragm: Do not crack diaphragm
in a way that white lines at the diaphragm upper side oc-
cur.
➨ Check for washers under clamping disc. Do not mix the
washers from the different heads. Make sure that the origi-
nal number is reassembled at the individual pump head.
☞ Smaller number of washers: The pump will not attain final
vacuum. More washers: Clamping disc will hit head cover;
noise or even blockage of the pump.
➨ Position new diaphragm between diaphragm clamping
disc with square head screw and diaphragm support disc.
☞ Note: Position diaphragm with light PTFE side to dia-
phragm clamping disc (to pump chamber).
Replacing the valves and assembling the pump heads
➨ Lift diaphragm carefully.
➨ Apply pressure to the clamping disc beside the diaphragm
to bring connecting rod into upper turning point position if
necessary.
☞ Never use a spiky or sharp-edged tool to lift the dia-
phragm.
➨ Use diaphragm key to grip under the diaphragm to the dia-
phragm support disc.
➨ Apply pressure to the diaphragm clamping disc to bring
the diaphragm into lower turning point position. Press dia-
phragm key against diaphragm clamping disc and unscrew
diaphragm support disc with diaphragm.
☞ If the old diaphragm is difficult to separate from the support
disc, immerse assembly in naphtha or petroleum ether. Do
not inhale!
☞ Check for washers under clamping disc. Do not mix the
washers from the different heads. Make sure that the origi-
nal number is reassembled at the individual pump head.
Replacing the diaphragm