Bell & Gossett MK MV (8202, 8202X) - Manual (Page 35)

Maintenance
Precautions
DANGER:
Disconnect and lock out electrical power before installing or servicing the unit.
WARNING:
• Always follow safety guidelines when working on the product. See
Introduction and
Safety (page 3).
• Make sure that the unit cannot roll or fall over and injure people or damage property.
• Rinse the unit thoroughly with clean water before working on the unit.
• Rinse the components in water after dismantling.
Make sure that you follow these requirements:
• Check the explosion risk before you weld or use electrical hand tools.
• Allow all system and pump components to cool before you handle them.
• Make sure that the product and its components have been thoroughly cleaned.
• Do not open any vent or drain valves or remove any plugs while the system is
pressurized. Make sure that the pump is isolated from the system and that pressure is
relieved before you disassemble the pump, remove plugs, or disconnect piping.
Maintenance guidelines
During maintenance and before reassembly, always remember to perform these tasks:
• Clean all parts thoroughly, particularly O-ring grooves.
• Change all O-rings, gaskets, and seal washers.
• Lubricate all springs, screws, and O-rings with grease.
During reassembly, always make sure that existing index markings are in line.
The reassembled drive unit must always be insulation-tested and the reassembled pump
must always be test-run before normal operation.
Torque values
All screws and nuts must be lubricated to achieve correct tightening torque. Screws that
are screwed into stainless steel must have the threads coated with suitable lubricants to
prevent seizing.
If there is a question regarding the tightening torques, please contact the local sales and
service representative.
Screws and nuts
Table 1: Stainless steel, A2 and A4, torque Nm (ft-lbs)
Property
class
M4 M5 M6 M8 M10 M12 M16 M20 M24 M30
50 1.0 (0.74) 2.0 (1.5) 3.0 (2.2) 8.0 (5.9) 15 (11) 27 (20) 65 (48) 127 (93.7) 220 (162) 434 (320)
70, 80 2.7 (2) 5.4 (4) 9.0 (6.6) 22 (16) 44 (32) 76 (56) 187 (138) 364 (268) 629 (464) 1240
(915)
Maintenance
MK, MV (8202, 8202X) Installation, Operation, and Maintenance Manual 33