User manual

Bio-inert Quaternary Pump User Manual 105
Test Functions and Calibration
8
Leak Rate Test
Potential Causes of Leak Rate Test Failure
Secondary Leak
If a leak is found for movement of piston 2 (secondary leak), the following
reasons are possible:
Primary Leak
If a leak is found for movement of piston 1 (primary leak), any leak described
for piston movement 2 will cause a failure for piston 1 as well, as the liquid
can move through the outlet valve to chamber 2. Such cases need to be
identified as described before. Additionally, following causes are possible:
Internal Outlet Valve Leak
A leak of the outlet valve will be identified separately (internal outlet valve
leak) by calculating the difference between leak rate 1 and leak rate 2. If the
second leak rate is higher than the first one, this is due to a flow back through
the outlet valve.
Probable cause Suggested actions
1 System not flushed properly
Flush system for several minutes
2 Degassing efficiency is low
Check degasser performance
3 Purge valve not closed or defect
Check purge valve
4 Blank nut not installed tightly
Tighten or replace blank nut
5 Outlet valve leaking (read below)
Replace outlet valve
6 Leak at piston 2 or seal in chamber 2
Inspect piston, replace piston and/or seal
Probable cause Suggested actions
1 Leak at piston 1 or seal in chamber 1
Inspect piston, replace piston and/or seal
2 Leak at inlet valve
Replace inlet valve or inlet valve cartridge (AIV only)
Probable cause Suggested actions
1 Leak at outlet valve
Replace the part which has failed and re-run the test.