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Waters 2695 wet prime / Compress check error
Posted: Mon Jul 12, 2010 9:59 pm
by flora0975
I am new for waters system..
We have a system of waters 2695 which hasn't been used for few months. The storage solvent is enough with 50:50/H2O:ACN.
I am trying to wet prime (warm-up for a new method). The pressure is low as ~20 psi, then I tried compress check, it can not go through with the error of "restriction missing"
What should I do now?
Posted: Tue Jul 13, 2010 1:06 am
by rwang
Is the column removed from the system? The compression check requires presence of either a column or a flow restrictor which generates >1000psi at 3 ml/min.
Posted: Tue Jul 13, 2010 3:02 am
by flora0975
Yes, the column is conectted.
Is the column removed from the system? The compression check requires presence of either a column or a flow restrictor which generates >1000psi at 3 ml/min.
Posted: Tue Jul 13, 2010 7:26 pm
by LC_labrat
20 psi is very low with a column attached what is the flow rate?
I suggest removing the column and attaching a union.
Wet-prime all solvent lines. 7.5ml/5mins
Prime the Pump Seal Wash
Prime Needle Wash
Purge Injector
Methanol is a better choice and will remove any gas bubbles in the lines, it should also be degassed prior to use.
Then put the column back on wet-prime solvent line with fresh 50/50 water/acetonitrile and try the compression check again (which tells you if there is a leak)
Posted: Wed Jul 14, 2010 8:30 am
by aceto_81
Probably your checkvalve is sticking.
Sonicate in methanol for a few minutes, then wetprime your system with methanol and check if you have some pressure.
Ace
Posted: Fri Jul 16, 2010 3:40 pm
by juddc
I'd sonicate in warm DI water or a methanol water mixture rather than neat methanol. If you have residual salts on your check valve, water does a better job removing them. Adding some methanol helps break the surface tension of the water and is often helpful, though.
My advice - get a reliable flow going with neat, degassed methanol, install your column, double check your flow, then perform several purges before worrying about passing a compression check. Your system is likely full of air.