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Loud noise comes from ACQUITY QDa pinch valve assembly (KAD model) - WKB75987

Article number: 75987

SYMPTOMS

  • Excessive noise comes from the QDa internal exhaust pinch valve assembly (KAD model)
  • The instrument operates normally without error messages
  • The source pressure test passes
  • Noise is continuous during routine system operation
  • Nitrogen consumption is higher than normal
  • Nitrogen inlet pressure unstable when the QDa is in Operate mode
  • Nitrogen leakage can be sense from the drip tray.

ENVIRONMENT

  • ACQUITY QDa Mass Detector

CAUSE

Faulty or leaking internal pinch valve assembly

Audio file of nitrogen leaking through internal pinch valve:

QDa pinch valve leak N2.m4a

FIX or WORKAROUND

Reseat the pinch valve, tightening the four hex screws.

It reseating does not work, replace pinch with new one. Black plastic one has been replaced with stainless steel of the same part number. valve part number: 700011173

 

ADDITIONAL INFORMATION

See the ACQUITY QDa Overview and Maintenance Guide for replacing the Internal Pinch Valve Assembly.

If reseating doesn't work, replace the KAD model internal pinch valve assembly - WKB120623

id75987, QDA

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