The Problem
An Agilent HPLC quaternary pump was reported leaking during high-pressure operation. Visible solvent leakage and pressure instability were affecting routine methods, making the system unreliable for analytical runs.
Diagnostics
ScientifiCo performed leak isolation while the pump was operated under pressure. Two leak areas were identified: one at the inlet tubing connection to the inlet valve and another between the pump head and pump body. The pattern of leakage suggested both a fitting-side issue and internal contamination inside the pump assembly.
Pump Repair
The inlet valve was removed and cleaned to eliminate salt buildup at the tubing connection. This corrected the fitting-side leak, but further testing showed continued leakage at elevated pressure.
The pump was then fully disassembled. Significant salt precipitation was found inside the pump components, which can prevent proper sealing and create unstable pressure behavior. The contaminated parts were cleaned thoroughly, inspected, and reassembled for testing.
Verification
After reassembly, the pump was tested at the customer operating range. Pressure and leak testing were performed up to 400 bar to confirm that the pump could hold pressure without external solvent loss.
Result
The HPLC system passed pressure and leak testing at 400 bar. No external leaks remained during normal use, and the quaternary pump was returned to stable operation for routine HPLC methods.
