6
Biffi
ICON 2000
InstructIon and operatIng manual
3.2.1 type “a” coupling block
3.2.1.1 preparing the bushing
With a compass key, unscrew the lower
ring nut�
Extract the stem nut from the block housing�
The internal thrust bearing will remain at the
bottom of the block housing�
iMportant
Before re-mounting the stem nut, make sure the
coupling tolerances to the valve stem are correct.
The threaded stem nut must be checked either
with a thread gauge or with the stem of the valve
to be motorized by screwing it all along the valve
stem without excessive friction.
Now the bore can be machined in the stem nut
to suit coupling requirements�
The same procedure is also used for possible
maintenance�
3.2.1.2 re-assembling the internal parts
It is advisable to wash the dismantled
parts with a suitable solvent; dry them with
compressed air; make sure there are no metal
filings or foreign bodies; spread a film of grease
on all parts (for grease type, see chapter 4,
Lubrication)�
Proceed with the assembly of the internal parts
following the reverse order of the disassembly;
tighten the lower ring nut with thread sealant
LOCTITE 270 or equivalent, making sure the
stem nut still rotates freely; fix the unit to the
gear reducer as described further on�
