Working On The Cutting Knives; Replacing And Checking The Cutting Knife Mountings - Virtus H 80 Series Operating Manual

PART A: Basic machine
Granulator
H 80 Series
8.12

Working on the cutting knives

8.12.1

Replacing and checking the cutting knife mountings

 Tighten the mounting screws on the cutting knives using a torque
The required torque for the knife fixing bolts is 580 Nm.
Bolt type
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In the case of granulators, the correct grinding properties, correct
setting and mounting of the cutting knives are important factors to
ensure perfect functioning and economic operation of the
machine.
Due to their function, certain machine parts are subject to stress in
their operating state as a result of vibrations, which can lead to
loosening of the screw connections. Therefore, it is absolutely
necessary to check the cutting knife mounting screws in
accordance with the Maintenance plan.
wrench which is set to the required torque for the screw size.
You can find out the required torque from the following table. Take
note too that the tightening capacity decreases of screws which
have been loosened and tightened again several times.
New screws of the same material quality must therefore replace
the cutting knife mounting screws after they have been loosened
and tightened several times.
Torque:
Grade 8.8
Nm lbf ft
M8 25 18.4
M10 49 36.1
M12 86 63.4
M16 210
M20 410
M24 710
Grade 10.9
Nm lbf ft
35 25.8
69 50.9
120 88.5
154 295 217
302 580 428
523 1000 737
Grade 12.9
Nm lbf ft
41 30.2
83 61.2
145 106
355 261
690 508
1200 885
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