If the Basic Tightness Test is not available in the chromatography data system for your Vanquish system configuration, test the pump manually. Manual testing requires user interaction.
TIP
With the dual pump, test each pump separately.
Parts and additional items required
Fitting plug, Viper
Solvent suitable for your application
Follow these steps
Disconnect the capillary on the pump outlet.
Close the pump outlet with the fitting plug.
In the chromatography data system, set the upper pressure limit to the appropriate value:
Pump | Upper Pressure Limit |
---|---|
VC‑pump | 60 MPa |
VF‑pump | 80 MPa |
Apply a flow of 50 µL/min and use the solvent for the application.
Observe the pressure. When the pressure reading is as indicated in the table, change the flow rate to a lower value.
Pump | Pressure |
---|---|
VC‑pump | Between 30 MPa and 40 MPa |
VF‑pump | Between 60 MPa and 70 MPa |
Have the pump deliver until the following pressure has built up:
Pump | Pressure |
---|---|
VC‑pump | 55 MPa |
VF‑pump | 75 MPa |
When the pressure has built up, apply the following flow:
Pump | Flow |
---|---|
Standard pump | |
VC‑P10, VC‑P20, VC‑P32, VC‑P40 | 1 µL/min |
VC‑P21, VC‑P33 | 4 µL/min |
VF‑pump | 1 µL/min |
Pump modified for NP applications | |
VC-P20, VC-P21, | 4 µL/min |
VC-P10 | 6 µL/min |
Observe the pressure.
The pressure should increase or remain constant for a minimum of 1 minute. A drop in pressure indicates possible leakage.
Find and eliminate the cause for the leak.
Take remedial action only when the system pressure is down to zero.
Possible Source | Remedial Action |
---|---|
Capillary connections | Inspect the capillary connections for signs of leakage. Tighten or replace leaky connections when the system pressure is down to zero. |
Piston seals |
|
Check valves |
|
Purge valve knob | Inspect the purge valve knob and purge outlet for indications of leakage. |
After taking a remedial action, test the pump.
Testing the Pump
Pressure up the pump.
This is the best way to identify whether a connection is leaky.
Allow 5 minutes for the pressure to stabilize.
This is important. The pressure drops faster during the first 5 minutes until the seals and other components have adjusted to the pressure.
After the stabilization time, monitor the pressure drop.
Tighten the connection that you want to test a little more. The pressure will suddenly increase a little.
Monitor if the pressure drops at the same rate as before. If the pressure drops significantly slower, the connection was leaky.
When testing the pump for leakage is complete, reset the upper pressure limit to the value used before the leakage test.