User Guide

1400 Series Granulators Chapter 5: Maintenance 24 of 43
Bed Knives
We recommend that the same screws and washers be re-used only when the bed knives have
been repositioned or re-ground. When blunt knives are discarded and replaced with new
knives, use new screws and washers. This will reduce the risk of screw failure due to their
overstretching. Screws and washers must be replaced with the type specified in the Spare
Parts List. Use the following procedure to replace or adjust the bed knives:
1. Access the cutting chamber as directed in Section 3-4 on page 18.
2. Loosen the check nuts on the bed knife adjusting screws and back off screws.
3. Remove the bed knife shields.
4. Disengage the bed knife pull screws.
5. Remove the bed knife bolts and bed knives.
6. Before installing and adjusting the bed knives, check all rotor knives to make sure
they are properly seated on the rotor and securely fastened.
7. Place the downstroke bed knife and its shield in place and hand-tighten the knife
bolts to hold them firmly to the knife seats.
8. Using the push and pull screws to set the knife clearance to 0.005” to 0.008” for most
materials; 0.014” to 0.016” for solid wall pipe with 0.187” wall thickness or greater.
The clearance should be measured with a feeler gauge at the ends of the knife, by
rotating the rotor sheave backwards by hand. The clearance is slightly greater at the
center of the knives.
9. Adjust the shield using its push and pull screws so that its front edge is within 1/16”
of the bed knife edges.
10. Tighten all bolts using the recommended torque values in Section 7-1 on page 32.
11. Repeat steps 7 through 10 for the upstroke bed knives.
5-4 Sharpening the Knives
Under normal operating use, the cutting edge of the knives will eventually become dulled,
resulting in reduced cutting efficiency. The blunt knives may either be re-ground to restore
the cutting edge, or replaced with new knives when regrinding is not possible.
When sharpening, it is not harmful to allow a few small nicks to remain in the cutting edge.
Grinding the cutting edge until perfectly clean can sometimes be wasteful.