
SMB/SB Installation and Maintenance Manual
140-11000 • July 2003
6
Maintenance
6.1 Routine Maintenance
a
WARNING: See Section 4.1 and 4.2 for Safety Precautions and Safety Practices before performing
maintenance.
NOTE: A routine maintenance check should be performed every 18 months as a minimum. The frequency can increase based upon the
frequency of operation and the ambient environmental conditions.
The routine maintenance check consists of the following:
1. Remove the limit switch compartment and/or control cabinet cover. Inspect for moisture. If moisture is present, dry the
compartment and the components.
2. Inspect all electrical controls and contacts in the limit switch compartment and/or control cabinet. Wipe clean all electrical
contacts with electrical-type solvent cleaner similar to CRC Lectra Clean and remove foreign residue.
3. Check armature brushes for proper contact and wear when DC motors are employed.
4. Verify all terminal connections are tight.
5. Clean gasketed surfaces on limit switch compartment and/or control cabinet cover. Inspect gaskets and seals for damage.
Replace all damaged gaskets or seals for weatherproof and submersible units. Wipe a coating (approximately two mils) of
lightweight bearing grease on surfaces of explosionproof cover flanges for protection.
6.
Inspect lubricant in accordance with Section 6.3.1, Lubrication Inspection. Visually check shaft penetrations for indications
of seal leakage. If abnormal leakage is found, replace the seal.
NOTE: Slight oil weepage is not a cause for seal replacement. See Section 6.2, Major Maintenance.
7. Megger test the motor—1 megaohm or higher is considered normal.
8. Clean and lubricate the valve stem for rising stem applications in accordance with the valve manufacturer’s lubricant
recommendation.
6.2 Major Maintenance
NOTE: Major maintenance is required when an operational deficiency is evident. The deficiency should be thoroughly evaluated to
determine the extent to which major maintenance should proceed.
Major maintenance consists of the following:
1. Perform all routine maintenance checks. See Section 6.1, Routine Maintenance.
2. Disassemble deficient portion of equipment.
3. Replace damaged or excessively worn components with new factory parts.
NOTE: Replace the Worm and Worm Gear as a set to ensure the greatest benefit from replacement. Replace the entire limit switch gear
box rather than attempt repairs in the field.
4. Replace all torn gaskets and seals.
5. Inspect stem and stem nut threads carefully for wear and/or damage.
6. Verify all electrical control components are operating before reinstallation.
6-1
Flow Control Division
Limitorque Actuation Systems