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HPLC Pressure Fluctuating - WKB10722

Article number: 10722

SYMPTOMS

  • Pressure fluctuating from 0-600 psi with and without column.
  • Priming does not help.
  • Peaks are eluting late.
  • Pressure dropout on plunger stroke
  • Loss of pressure
  • Sonicating check valves does not solve the issue

ENVIRONMENT

  • Alliance HPLC System
  • 2695/e2695/2795/2690/2790 Separations Module
  • 515 HPLC Pump
  • 1500 series

CAUSE

Faulty check valves.

FIX or WORKAROUND

  1. Replace the check valves with new valves of the correct type (See video below).  Standard check valves, 700000254
    1. PerformancePLUS CV Cartridges, R/S, 1/8-in (700000254)
    2. Check Valve Cartridges, R/S, 1/16-in (WAT270941)
    3. PerformancePLUS CV Cartridge, Ceramic, 1/8-in ( 700002399)
    4. Check Valve, Ceramic (700002333)
    5. Check Valve Cartridge, R/S , Titanium (700002255)
    6. For 2790/2795, also replace Check Valve Cartridge, Ceramic, 1/16-in (700002761)
  2. If high delta psi or pressure fluctuation persists post new check valves replacement, then check system CD ratio (See video below.)  If CD ratio > 1.80, consider to rebuild pump with Alliance solvent manager PM kit, 700004073.
  3. Confirm that no more pressure drops are present.

ADDITIONAL INFORMATION

Replacing Alliance system Check Valve Cartridges

Checking the C/D Ratio on an Alliance 2695 HPLC

 

pressure ripple

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