Pfeiffer Vacuum MVP 030-3 DC, Руководство по эксплуатации

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9.5 Checking the ultimate pressure
The leakage rate of the vacuum pump ensures that the specified ultimate pressure is reached and pre-
vents 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 ultimate pressure val-
ue only after a run-in period of several hours.
Procedure
1. Measure the ultimate pressure of the vacuum pump.
– after work on the system, e.g., maintenance
– before the vacuum pump is reinserted
2. Compare the measured ultimate pressure with the test values and the specifications in the techni-
cal data.
Test values
Observe the separate test specification.
● with gas ballast: < 3 hPa
● without gas ballast: < 2.0 hPa
Prerequisites
● Vacuum pump mounted
● Vacuum pump correctly installed electrically
Required aids
● Vacuum chamber (3 liter)
● Pressure gauge
● Flushing gas nozzle
Measure the ultimate 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 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 ultimate 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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