Thermo Scientific 42iQD, Instruction Manual

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Maintenance
Pump Rebuilding
5-6 42iQD Instruction Manual Thermo Scientific
screws and then remove the cover. Re-use any gasketing. Remove any
debris that may have accumulated in the bottom of the compressor
housing.
4. Remove the four screws with the 2.5 mm allen wrench and remove the
headplate. Note the positioning of the valveplate relative to the valve
ports on the headplate and intermediate plate. Lift off the valveplate.
5. Remove the intermediate plate.
6. Check that all parts are free from dirt and clean as necessary. Do not
scratch the parts.
7. Removal of the old diaphragm: Rotate the fan so that the diaphragm is
positioned at the top dead center. This will help unseat the edge of the
diaphragm. If required, push up from underneath the diaphragm or use
a
non-metallic
tool to pry up the diaphragm from the housing groove.
Do not scratch the head components. Unscrew the old diaphragm by
turning it counterclockwise using both hands. Lift up and grip the
edges of the diaphragm at 10 and 4 o'clock. High initial force may be
required to break the diaphragm loose.
Do not use tools!
(Note: - Take
care not to lose any shim rings positioned between the diaphragm and
connecting rod, as the exact number of shim rings must be used during
re-assembly.) While unscrewing the diaphragm with one hand, use
your other hand to secure the shim rings onto the diaphragm stud. Lift
the diaphragm, and shim rings from the pump. The compressor
housing cover must be removed (See step 3) to gain access to and secure
the shim rings onto the stud. Note: the quantity and thickness of shim
rings will vary from pump to pump.
8. It is not necessary to remove the diaphragm ring (040) from the
compressor housing groove but if it falls out it must be put back in
place.
Assembly with new diaphragm and valveplate:
1. Place the shim rings removed in step 7 above onto the threaded stud of
the new diaphragm. Carefully screw the new diaphragm into the
connecting rod. It is helpful to hold the connecting rod at a slight angle
until the threads are started. Spin the diaphragm on until it is snug. Lift
and grip the edges of the diaphragm at 7 and 2 o’clock and tighten
firmly using both hands. DO NOT use tools!