Primary pump passes dynamic leak test with negative leak rate values - WKB196173

SYMPTOMS

• Successful dynamic leak test 
• Primary pump head passes dynamic leak test with negative leak rate values
• Primary pump head occasionally passes with acceptable leak rate values
• Increase of leak rate on accumulator seen when leak rate on primary is monitored
• Seals and check valves are new, replaced more than once on both primary and accumulator pumps

ENVIRONMENT

• ACQUITY UPC2 ccBSM
• ACQUITY UPLC I-Class BSM
• ACQUITY Classic

CAUSE

Faulty primary pump head

FIX or WORKAROUND

1. Replace the primary pump head.
2. Perform the dynamic leak test.

ADDITIONAL INFORMATION

High pressure seal marks might be seen on primary pump head.