"System over pressure" error on ACQUITY UPLC H-Class - WKB111976

SYMPTOMS

• "System over pressure" error on ACQUITY UPLC H-Class
• High pressure observed at very low flow rates
• Pressure drops to <10 psi when loosening port 6 on the sample manager injection valve 

ENVIRONMENT

• ACQUITY UPLC H-Class
• ACQUITY UPLC I-Class

CAUSE

The tubing from port 6 on the sample manager injection valve to the column manager selection valve was blocked.

FIX or WORKAROUND

1. Disconnect the tubing from port 6 on the sample manager injection valve to the column manager selection valve.
2. Reverse the tubing and connect it only to port 6.
3. Back flush the tubing at low flow rate with a solvent in which the sample may be soluble (e.g., water or a water:methanol mix) and monitor for pressure drop.
4. Refit the tubing in its original orientation.

ADDITIONAL INFORMATION