Replacing the diaphragm – VACUUBRAND PC 3012 VARIO plastic housing User Manual
Page 115
page 115 of 129
Replacing the diaphragm
+
Check diaphragm (F) for damage and re-
place if necessary.
➨
Lift diaphragm carefully sidewise.
+
Never use a pointed or sharp-edged tool to
lift the diaphragm.
➨
Use the diaphragm key to grip the diaphragm
support disc (G) below the diaphragm.
➨
Unscrew diaphragm support disc (G) with diaphragm (F) and dia-
phragm clamping disc (E).
➨
Check for washers (H) between the diaphragm support disc (G) and
the connecting rod (I) . Do not mix the washers from the different pump
heads, since these are set at the factory to ensure proper pump per-
formance. Make sure that the original number is reassembled at the
individual pump head.
+
Too few washers: The pump will not attain vacuum specification. Too
many washers: Diaphragm clamping disc will hit head cover, causing
noisy operation and possibly causing the pump to seize up.
+
If the old diaphragm is difficult to separate from the diaphragm support
disc, immerse assembly in naphtha or petroleum ether. Do not inhale
vapors!
➨
Position new diaphragm (F) between dia-
phragm clamping disc with square head
screw (E) and diaphragm support disc (G).
+
Note: Position diaphragm with pale side
towards diaphragm clamping disc (facing
pump chamber).
+
Make sure that the square head screw of the diaphragm clamping disc
is correctly seated in the guide hole of the diaphragm support disc.
➨
Lift the diaphragm at the side. Place the diaphragm carefully together
with diaphragm clamping disc and diaphragm support disc in the dia-
phragm key.
+
Avoid damage of the diaphragm; do not excessively bend or crease
the diaphragm too much.
F
E
E
G
F