12. Tighten countersunk screws on clamping claws.
– Tightening torque:
3 Nm
13. Fit hose for hose connection.
14. Fit hose clamp on connection hose.
15. Tighten hose clamp on connection hose with flat pliers.
16. Fit head cover hood.
17. Screw in oval-head screws and clamping washers on head cover hood.
18. Tighten oval-head screws on connection holder.
19. Close integral hinge on connection holder.
7.7 Checking the final pressure
The leakage rate of the vacuum pump ensures that the specified final pressure is reached and prevents
the formation of potentially explosive mixtures in the interior of the vacuum pump
After the diaphragm or valve is replaced, the vacuum pump reaches the specified final pressure value
only after a run-in period of several hours.
Test values
Observe the separate test specification.
● with gas ballast: < 3 hPa
● without gas ballast: < 2.0 hPa
Procedure
1. Measure the final pressure of the vacuum pump.
– after work on the system, e.g., maintenance
– before the vacuum pump is reinserted
2. Compare the measured final pressure with the test values and the specifications in the technical
data.
Prerequisites
● Vacuum pump mounted
● Vacuum pump correctly installed electrically
Required aids
● Vacuum chamber (3 liter)
● Pressure gauge
● Flushing gas nozzle (optional)
Measure the final pressure
1. Connect a vacuum chamber (volume approx. 3 l) to a vacuum connection.
2. Also connect a pressure gauge (e.g. Pirani gauge) to the vacuum chamber on the vacuum side.
3. Operate the vacuum pump with open flushing gas nozzle (if available) for at least 2 hours.
4. If unusual noises develop, immediately switch off the vacuum pump and check the position of the
clamping washers.
5. Measure the final pressure.
Comparing the ultimate pressure with the test value
1. Compare the measured ultimate pressure with the test value.
2. If the values differ significantly from the specified values after replacing the diaphragm and valve,
and if there are no changes after a run-in period, perform the following steps:
– Check the compression couplings of the connection hoses to the pump heads.
– Check the valve seats and the suction chambers.
– Repeat the ultimate pressure measurement.
Maintenance
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