Frame Maintenance - Repair Of Main Frame; Routine Weld Repair - NPK M20S Instruction Manual

FRAME MAINTENANCE – REPAIR OF MAIN FRAME
Inspect frame for cracks periodically. Crushing or shearing is an abusive operation and
eventually frame cracking may occur. If the attachment has been overstressed due to
improper operation or has been used for many hours of operation, the steel
components may develop fatigue cracks.
components of the processor, photos of the crack or cracks must be emailed to NPK
immediately so that the crack can be evaluated and a repair option recommended.

ROUTINE WELD REPAIR

1. Gouge any cracks 100% using an air
or electric hand held grinder (t1),
carbon arc (t12) or torch (t13).
2a. Grind gouged area to a 30° angle on
each side to the full depth of the
gouged area for plate sizes up to 3/4"
(19 mm) thick.
2b. Grind gouged area to a 45° angle on
each side to the full depth of the
gouged area for plate sizes over 3/4"
(19 mm) thick.
3. If the crack is completely through the plate, grind the bevel in halfway from both
sides. Remove all slag and grinding residue.
4. Consult the "JAW and TOOTH REBUILD PROCEDURE, HARDFACE" section for
pre-heat and welding instructions.
5. Peen or stress relieve after each pass. Maintain pre-heat.
6. After welding, grind area flush.
DIRECTION OF GRINDING
22
DIRECTION OF PRINCIPLE STRESS
23
If cracking is found in any of the steel
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