- ACQUITY pump overpressure
- ACQUITY UPLC I-Class FTN
Blockage in the flow path on the SM-FTN side causes the ACQUITY pump to overpressure.
FIX or WORKAROUND
Depending on where the blockage is, replace one or more of the following:
- Injection valve cartridge (700006057)
- Needle for I-Class FTN (700011628)
- Vespel seat (405011492)
- Seat port tubing for I-Class (700006056)
Also check inside the peek wash housing assembly for any signs of obstruction caused by solid residue left over after injections, This can removed with tweezers if possible.
Pressure diagnostics to pinpoint the blockage on the SM-FTN:
1. Disconnect the tubing from pump to inject valve port 5, set some flow, ensure that there is no overpressure and that liquid is coming out of the tubing.
2. Connect the tubing from pump to inject valve port 5. Disconnect the tubing on port 1 (seat port tubing). Set some flow, and ensure that there is no overpressure and that liquid is coming out of inject valve port 1. (Ensure that the inject valve is in the inject position; if needed, adjust this in the interactive display in the console.) If overpressure, the inject valve is blocked.
3. Remove the needle from the needle carriage. Connect the needle to inject valve port 1 and set flow (inject valve on load position). If no overpressure, the needle is ok; if overpressure, replace the needle.
4. Back-flush the seat port tubing. Remove the needle from port 4. Remove the seat port tubing from the seat port assembly and remove the vespel seat. Connect the seat port tubing to inject valve position 4. Set flow, check pressure (inject valve on inject position). If the pressure increases, replace the seat port tubing.
5. Install the vespel seat and reassemble the seat port assembly unit. Connect again to port 4 of inject valve, set flow, and check the pressure. If pressure is increasing (overpressure), replace the vespel seat.
6. Install the needle in the needle carriage and connect to inject valve port 4. Assemble/install the seat port assembly if needed, but do not connect to inject valve port 1. Set flow and check the pressure.
7. Connect the seat port tubing to inject valve port 1. Now the instrument is back in normal configuration. Set flow and check pressure (if overpressure, replace the inject valve and check again).
8. Calibrate the needle z-axis.
9. Characterize the needle seal.
10. Perform the needle seal readiness test.
11. Do injections to check the stability of the pressure in the normal flow path.