BUCHI Distillation Unit K-355 - Manual (Page 26)

7 Maintenance and repairs
26 K-350 Operation Manual, Version F
7 .1 .4 Preparing the instrument for a standstill overnight
To prepare the instrument for a longer standstill (e.g. overnight), fill 50 ml distilled water into the
receiving vessel and 0 ml of distilled water into the sample tube.
7 .2 Weekly maintenance
7 .2 .1 Cleaning the splash protector and the rubber bung seal
Unmount the splash protector and remove the rubber bung seal.
Rinse the splash protector with water to remove sample residues.
We recommend to replace the splash protector after approximately 5000 determinations, depending
on the kind of application and frequency of maintenance.
To prolong the lifetime of the seal, rinse it with water, especially if working with crystalline products.
Afterwards, dry it with a soft cloth, remount it and put the splash protector back in place.
ATTENTION
When removing and reinstalling the seal, make sure not to damage it. Always move it perpendicularly
to the axis of the glass parts and ensure no damage occurs to the sealing lip.
Never apply grease to the seal and never touch it with sharp objects, otherwise it will get damaged.
7 .3 Monthly maintenance
7 .3 .1 Checking the distillate amount
To check the distillate amount, wait until the steam generator is ready, i.e. the instrument is warmed
up. Then run a single sample with an empty tube and an empty receiving vessel with the following
parameters:
Table 7-1: Checking the distillate amount
Parameter Setting
Check distillate amount: Distillation and titration
Sample tube: empty
Water: 0 ml
NaOH: 0 ml
Distillation time: 5:00
After the check is finished, measure the distillate amount by means of a measuring flask. With the
above parameters it should be
about 150 ml.