when first installing your cryostream , run the system without fitting the line drier . if there are any inward leaks or a high level of ice in the liquid nitrogen , the cryostream will block in a few days but will not contaminate the line drier with water . if this occurs , re-check all the quick-release fittings , check the liquid nitrogen in the dewar vessel for ice contamination then rerun the system . thecryostream should run for about 5-7 days before a block occurs , although poor quality nitrogen can reduce this to 2-3 days (the alarm lamp will flash and on pressing the alarm button the status screen with indicate a pressure warning on the cryostream ) . if none of these appear then the quality of the liquid nitrogen is very good .