Thermo Scientific 42i Instruction Manual page 160

Preventive Maintenance
Pump Rebuilding
5-6 Model 42i Instruction Manual
4. Remove four screws from top plate using the 3 mm Allen wrench.
5. Remove top plate, flapper valve, and bottom plate.
6. Using needlenose pliers, remove clamping disk holding diaphragm and
Teflon protection wafer onto clamping rod, and remove the diaphragm
and Teflon wafer.
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