the pressure of our WATERS 2695 jump heavily ?

[weeker2001]

it has been a whole year there nothing problem happen on my instrument .2996 PDA detector ,and 2695 seperation module .we just do some routine analysis .1 year ago we just do a maintainance performance by the engineer of waters .i "wet prime"the four channel.and run with methol 100% with the single channel .still the pressure going up and down ,about 100 psi or more .i gave a call to 800.the engineer told me that maybe the seal went wrong . but no reagent flew out of the tube .what's wrong ? i can call a engineer to solve this problem,but it will cost a lot for me .

[danko]

If you don’t see any leaks, then the problem must be air bubbles. Do “dry primeâ€

[weeker2001]

we have decided to buy the plunger seal ,do it under the manual . thank you !

[danko]

If the problem was the plunger seal, you would’ve seen leaks just under the pump head. Anyway, it’s your money and besides, it’s nice to have some plunger seals in stock – when needed

Best Regards

[aceto_81]

If its a problem with the seals, you would see a constant flow at your sealwash.

I would bet on a bubble or checkvalve problem.

Ace

[weeker2001]

thank you for all your advice . the engineer came yesterday . when start the seperation module .then the head pump began leaking .it must be the plunger seal .easily ,he took off the head pump ,and the damaged plunger seal .insert the new one .then set uo the flow rate ,no jump of pressure ..... it was not the reason of bubble . so easily he did it ,if i overcome the problem,it would save a lot money .

[shahis77]

AIR IS THE PROBLEM....THERE ARE SMALL SCREWS JUST BELOW THE PUMPS IN YOUR SYSTEM START THE FLOW AT 1ML/MIN AND OPEN THOSE SCEWS TILL U FIND SOME LIQUID THERE.... YOUR PROBLEM WILL BE SOLVED THIS IS VERY EASY...

[HW Mueller]

Am I getting senile, did weeker2001 say that changing the seals fixed the problem?
Probably have to take another pill now which has been QC´ed here?

[danko]

What about the following interpretation: Changing the seals AND PURGING THE AIR BUBBLES fixed the problem?
Weeker2001 indicated in his/her initial post that there were no leaks to worry about.
Never the less, a leak was observed when the service engineer came and started the system.
So, can we summarize it as follows?
The seal was worn which gave way for some air to enter the pump interior. After changing the seal the possibility for air entering the pump interior was eliminated and that solved the problem. Had the leak been observed earlier (from the beginning) we would all had known that the seal needed to be replaced.

Best Regards

P.S. I’ve always dreamed of entering the arena of the UN policy