4.5
Testing leakage
When using the Pump P-920 regularly, a leakage test should be
performed every second month. When the pump is used
intermittently, a leakage test should be performed before every use.
After disassembly due to cleaning or repair, a leakage test should
also be performed before use.
Leakage is tested by checking the pump pressure against a blocked
outlet using distilled water and a 1/16” stop plug. The test is carried
out from the pump dial and display. A chart recorder connected to
the analogue pressure output can be useful to record the pressure
reading during the test.
1 Set the pump to 0%B and select a flow of 20 ml/min.
2 Set the high pressure limit to 4.5 MPa and press OK.
3 Run the A pump until the piston which is delivering flow is at
the middle of the glass cylinder. Stop the pump.
4 Plug the pump outlet at the pressure manifold using a 1/16” stop
plug (18-1112-52).
5 Select a flow of 0.2 ml/min.
6 Start the pump and let it run until the pressure limit is reached
and the pump stops.
7 Check the pressure reading for two minutes. The pressure must
not decrease more than 0.45 MPa during this time. If the
decrease is larger, see Chapter 5 Trouble-shooting for actions.
8 Release the pressure from the pressure manifold by loosening the
stop plug. Select a flow of 20 ml/min and run the A pump until
the other piston, which is now delivering flow, is at the middle of
the glass cylinder. Stop the pump.
9 Repeat steps 4-7.
10 Set the pump to 100%B and select a flow of 20 ml/min.
11 Release the pressure from the pressure manifold by loosening the
stop plug. Run the B pump until the piston which is delivering
flow is at the middle of the glass cylinder. Stop the pump.
12 Repeat steps 4-7.
13 Repeat steps 8 for the B pump.
14 Repeat steps 4-7.
15 Remove the stop plug and reconnect the outlet tubing to the
pressure manifold.
16 Store the pressure recordings in the system logbook.
Pump P-920
User Manual 18-1125-54 Edition AB
18
4
Maintenance
Stop plug
18-1125-54_ab.qxd 1998-10-22 12:49 Sida 18 (1,1)
