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Waters

Dip in 2414 Refractive Index Detector baseline - WKB200978

Article number: 200978

SYMPTOMS

  • Dip seen in baseline just after void volume 

ENVIRONMENT

  • 2414 Refractive Index Detector
  • Alliance HPLC System
  • 2695 Separations Module

CAUSE

Pressure relief valve is faulty, opening when pressure increase is seen from 2695 injection.

FIX or WORKAROUND

Replace the pressure relief valve (700002361).

ADDITIONAL INFORMATION

During normal operation, the pressure relief valve valve remains closed. It opens when the pressure for the flow cell, whose maximum pressure rating is 690 kPa (6.89 bar, 100 psi), gets too high. This protects the flow cell from exceeding the maximum pressure rating. The pressure rating of the relief valve is 103.4 kPa (1 bar, 15 psi).

The attachments show the flow path when the pressure relief valve is open or closed. When closed (normal operation), sample passes through the sample side of the flow cell only (positive peaks). When open, sample first passes through the sample side of the flow cell (positive peaks), and later through the reference side of the flow cell (generating the mirrored signal observed for the positive peaks).

id200978, 2414, 2414B, A-10RI, A-30RI, UPRI, UPRIARC

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