Hytek ALPHA Series Technical Data Manual page 8

MAINTENANCE
The Alpha should require minimum maintenance in normal regular
use, but as with all mechanical apparatus regular servicing will
prolong its life and ensure maximum efficiency & reliability.
The following should be carried out every 12 months or 1 million
litres which ever comes first.
Isolate power supply
-
Inspect & clean or replace pump filter
-
Inspect & clean or replace nozzle filter
-
Inspect & replace if necessary the V-belt
-
Check motor pulley grub screw is tight
-
Re-calibrate electronic display
-
S855/2