Pressure problem with UPLC Acquity BSM

gpanzarini

<p>Hi,</p><p>somebody can help me about to risolve the problem that is showed in attached file?</p><p>1. I have changed all seals;</p><p>2. I have changed  pump head  of primary A with pump head  of primary B and I have seen the same problem on the primary A;</p><p>3. I have replaced pump head primary B with Head of accumulator and I have seen the problem to the accumulator, so I have understand that the problem probably is on the head.</p><p>As, with the channel B, I generally use MeOH:ACN + 0.1 % Acetic acid I have changed too the seal wash housing, but I have always the same problem.</p><p>4. I washed the pump head with methanol in the sonicator but the problem don't change.</p>

Jeffreywd

HI, I don't have much experience with waters instruments yet.. but with the Hitachi intruments I would repair when the pressure would fluctuate as shown I would either change or sonicate the flow valves before and after the pump head. hope this solves your problems.

rune

Hi

This looks as either an inlet check valve problem on the primary B pump head or a seal leaking on the same head. Please observe that you should not swap a primary pump head with an accumulator pump head since the check valves on these pump heads are not the same.

I would start by changing the check valve. If you do not have a spare one take it off and put it in a sonication bath with first 100% water and the 100% organic for 20 minutes each.

best regards

Rune

gpanzarini

Thanks a lot for your answers.

I have delete the possibility that the problem is the check valve because I changed the Chek Valve B with Check Valve A and the problem rested on B and no on A.

When I changed the pump head from primary to accumulator I changed too the check valve. I changed only pump head.

Best regards

rune

Hi Again

I would then try the accumulator check valve on the B pump.

best regards