BSM accumulator or primary "unable to compress". Dynamic Leak Test failure after pump maintenance - WKB32496

SYMPTOMS

• BSM pump failing the Dynamic Leak Test with error: "Accumulator unable to compress" or "Primary unable to compress"
• Recent pump head maintenance

ENVIRONMENT

• ACQUITY UPLC BSM
• ACQUITY UPLC H-Class QSM

CAUSE

PEEK washer/gasket on the primary check valve displaced during fitting and squashed out of shape.

FIX or WORKAROUND

1. Remove check valve with improperly seated washer.
2. Replace PEEK washer:
   • 700005218 for the WASHER GASKET, HIGH PRESS, PEEK I2V - (for intelligent check valve i2V)
   • 700005221 for the WASHER, CHECK VALVE, PEEK (for accumulator check valve)
3. Prime system.
4. Run dynamic leak test.

ADDITIONAL INFORMATION

To prevent the PEEK washer from displacing itself during check valve installation, lightly wet the washer with a small amount of methanol when installing it on the check valve.  The methanol will create adhesion between the washer and check valve, preventing it from moving.