Dionex SRS Leak Problems

[PeteMartin]

I have been having an intermittent problem for some time now. To my relief, I finally discovered this board but didn't find a solution when I searched the topics.

My problem:

Both my ASRS ultra II and CSRS Ultra II have been leaking intermittently from the seam. Dionex tells me that there has the be a downstream pressure problem but I can't find one. All the pressures in this post were measured during the anion setup only (ASRS leaks more often).


My setup:

I'm running a DX-600 system with an EG-40 Eluent Generator (KOH). The EG-40 has a CR-ATC in it. It is a 4mm peek system with a std bore pump.

Downstream from the ASRS eluent out port looks like this:

ASRS Eluent Out -> Column Switching Valve
CS Valve -> Cell (Conductivity)
Cell -> CS Valve
CS valve -> ASRS Regen IN
ASRS Regen Out -> CR-ATC Regen In
CR-ATC Regen Out -> EG-40 Degas Regen In
EG-40 Degas Regen Out -> Waste


Observations and Pressures Measured:(@1.0mL/min)

ASRS Eluent Out -> Waste = 66psi
Cell In -> Waste = 53psi
Cell Out - Waste = 26psi
ASRS Regen In -> Waste = 13psi

Pump on by itself = 0psi


From these pressures I concluded that the CS valve and lines create about 13psi each pass, the cell creates about 28psi. I have measure the cell before at another time and found that it created 35-40psi but there haven't been any strange things in my chromatograms.

My standards and validation samples are all within a fairly reasonable range and I don't notice any unusual background noise.

Is it possible to have the backpressure of a specific component fluctuate (maybe CS Valve) to put me over my ASRS downstream limit or is 66psi high enough to get intermittent leaks?

Thanks for any input you can provide. I appreciate it

[kannan_srinivasan]

Dear Pete

Your backpressure numbers look reasonable and by itself should not cause any suppressor leaks.

Based on your setup it is possible that the column switching valve is dead ended for a brief moment causing a spike in high pressure and this may be the cause of your ASRS and CSRS suppressors leaking. I am assuming that you have the CSRS suppressor eluent out also hooked up to the same CSV.

To test if the CSV is the cause of the problem , I would suggest that you bypass the CSV and determine if you still observe leaks.

You can contact me at Kannan.Srinivasan@dionex.com
if you need any further help.

Cheers,

Kannan

[PeteMartin]

I've also noticed that the total backpressure fluctuates sometimes between 1675 and 1725. Today while this was going on, I connected my pump directly to the SRS regen out and found the pressure to be 78psi (instead of 66). I "tapped" on the CS valve the rubber handle of a wrench and the pressure dropped back down to 66psi and the leaking stopped.

Looks like I need to rebuild the CS valve. Thanks for your help and all those who e-mailed me.

If anyone from Dionex has the p/n for this item, please email me or post here (10-port, 2-position Rheodyne CS valve 9650E-033)

thanks

-Pete-
martinpe@agr.gc.ca

[kannan_srinivasan]

Hi Pete

Dionex sells a rebuild kit for the described valve and the part number for this kit is P/N 052280. This kit consists of a Rotor, Stator and isolation ring and you can address the leaking issue using this valve.

A replacement valve is available P/N 054486 but this is available only as a service assembly.

Let me know if you have any further questions.

Cheers,

Kannan

Kannan.Srinivasan@dionex.com