OPERATION & MAINTENANCE
TORQUE PROCEDURES
All Tomco
2
Equipment Co. Dry Ice Pelletizers are designed and built to provide
many years of service. However, these pelletizers undergo many cycles of severe
loading and unloading.
In order for the pelletizers to survive the fatiguing encountered with cyclic loading, it
is imperative that key components are torqued evenly and adequately. The torque
value is the amount of work (ft-lb., Nm, m kg) applied to the fastener. This torque
value will apply a large pre-load to the bolt and is very advantageous in reducing the
effects of fatigue. The result is a smaller variation in the cyclic loading occurring
during the extrusion of dry ice.
Figures 4.3 on the following pages show the torque sequences and final torque val-
ues for the fasteners that require torquing for each pelletizer model. The fasteners
should be torqued in four (4) steps. Following the torque sequence shown corre-
sponding to the appropriate assembly, torque each fastener to approximately 25% of
the recommended final torque value. Repeat the torque sequence three more times,
each time increasing the value by approximately 25% of the recommended final
torque value.
Example: Model HP-1000 Extrusion Die
Torque Value
Step 1 119 ft-lb (16 m kg) (161 Nm)
Step 2 238 ft-lb (33 m kg) (323 Nm)
Step 3 356 ft-lb (49 m kg) (483 Nm)
Step 4 475 ft-lb (66 m kg) (644 Nm)
Note: All threads must be clean and well lubricated with an appropriate lubricant.
Note: Check the torque value of each fastener immediately following the first 48
hours of operation and subsequently after every 500 hours of operation. Re-torque
if necessary. Repeat this after every scheduled cylinder rebuild.
4.17
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