When the machine arrives, the customer normally receives two items on paper: a factory test record and a certificate of conformity. The weight of these two documents does not rest on the conclusion that the machine is good, but on the record of which machine it was, under what conditions it was tested and what the readings were. If the document carries only a conclusion and no process, it is of almost no use at the acceptance stage.
A certificate of conformity only means something when it is bound to the equipment number
The certificate of conformity comes first. Its value comes from being bound one to one to the equipment number. The equipment number is the only clue that allows the machine to be traced after delivery; it appears on the documents, on the nameplate and in the customer's own records, and when the three agree the certificate refers to this machine rather than to a type or to a display unit. When the numbers do not agree, everything that follows about spare parts, drawings and parameter changes is misdirected.
What the factory test record should cover
A usable factory test record covers at least five areas: the no-load run, the load run, the vacuum level, the flow rate and the operation of the electrical protections. These five are not five isolated conclusions but a chain: the no-load run confirms that the mechanical parts are assembled correctly, the load run confirms that the performance indicators hold, and the protection test confirms that the machine stops by itself when something is wrong. Missing any one link leaves the record incomplete.
The no-load entry records the mechanical state: whether the pump rotation is correct, whether the coupling is aligned, whether there is leakage at the seals, whether the electrical circuits operate normally and whether there is abnormal noise during the run. The load entry records the performance: whether the working vacuum settles inside the -0.08 ~ -0.0999 MPa range, whether the processing flow rate reaches the rated value, and whether the temperature control and heating hold the oil temperature within the set range. The two are recorded separately because the sources of the problems behind them are entirely different.
| Record entry | What it should record | Typical symptoms when out of limits |
|---|---|---|
| No-load run | Pump rotation, coupling alignment, sealing leaks, circuit operation, noise | Wrong rotation, misalignment, oil leak, abnormal noise |
| Load run | Stable working vacuum range, processing flow rate, temperature control and heating | The vacuum level drops out of the range, insufficient flow, temperature rise out of control |
| Vacuum level | The working vacuum reading and the ultimate vacuum reading | The ultimate vacuum does not reach ≤5 Pa |
| Flow rate | The processing flow rate recorded at the rated duty | The flow rate falls after continuous running |
| Operation of the electrical protections | The audible and visual overpressure alarm and stop, the verification of the phase-loss and phase-sequence protection | The protection fails to operate or operates falsely |
What to check on the day the machine arrives
Start with the parts that can be checked without energising the machine: whether the equipment number is the same on the nameplate, the certificate and the test record; whether the documents supplied with the machine are complete; whether the pipe openings are properly blanked and whether water or dust got in during transport; and whether the cabinet doors, guards and fasteners have moved in transit. This is the difference between the machine having arrived and the machine being intact. Also check that the accessories supplied with the machine are complete, and that the installation bolts and the spare parts kit have not been left in the packaging.
- Consistent numbers: the equipment number is the same on the nameplate, the certificate and the test record.
- All items present: there are records for all five areas, no load, load, vacuum level, flow rate and operation of the electrical protections.
- Readings with conditions: each record states the test conditions and the measured value, instead of only the word "pass".
- Traceable: the type and the parameters on the documents agree with the nameplate.
The checks that need the machine energised are best carried out before the machine enters regular production: jog the pump by hand to confirm the direction of rotation, simulate the trigger of the protective functions, and check the start and stop response of the heating and the temperature control. The protective functions are worth testing on the spot, because a phase-loss and phase-sequence protection or an audible and visual overpressure alarm that is fitted to the machine but does not operate is usually found on site after the oil has already been interrupted once.
The test record has to answer which machine, under what conditions and with what readings, and the certificate has to match the equipment number; a record that has conclusions but no process is of no use at acceptance.