BUCHI Vacuum Pump V-710 - Manual (Page 43)

7 Maintenance and repairs
43 V-700/710 Operation Manual, Version E
7 .4 Valve head
7 .4 .1 Cleaning
If the end vacuum of 10 mbar is not reached anymore and the rest of the system has no leakage, the
problem is often caused by stuck valve plates.
To clean them, proceed as follows:
• Remove all connections to the pump and to the silencer.
• Switch the pump on.
• Inject a small amount of about approx. 10 ml of acetone at once into the inlet side of the pump and
wait until the pump makes the same sound as before injecting solvent.
NOTE
Use safety washing bottles to inject the acetone, as shown in Fig. 7.1.
• Repeat the injection step four to five times.
• Let the pump run for about 2 minutes and check whether the end vacuum can be reached.
• If this is still not the case, repeat the cleaning procedure before going on with any disassembly
work.
Fig. 7.1: Cleaning the valve head with acetone
7 .4 .2 Disassembly and reassembly of the pump head
To disassemble the pump to replace the membrane and valves, proceed as follows:
• Remove the two knurled screws for fixing the
upper part (position 4 in Fig. 4.2) and pull the
housing off.
NOTE
To replace only the valves you do not have to
remove the metal cover and the pump head.