Xylem Flygt Concertor 6020, Installation, Operation And Maintenance Manual

Page: 37 / 56

Inspect the work area before permit-required hot work
WARNING: Explosion/Fire Hazard
Before starting any permit-required hot work such as welding, gas cutting, grinding, or
using electrical handtools, do the following: 1. Check the explosion risk. 2. Provide
sufficient ventilation.
Ground continuity verification
A ground (earth) continuity test must always be performed after service.
Maintenance guidelines
During the 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, O-rings with grease.
During the 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.
8.1 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)
100 4.1 (3) 8.1 (6) 14 (10) 34 (25) 66 (49) 115 (84.8) 248 (183) 481 (355) — —
Table 2: Steel, torque Nm (ft-lbs)
Property
class
M4 M5 M6 M8 M10 M12 M16 M20 M24 M30
8.8 2.9 (2.1) 5.7 (4.2) 9.8 (7.2) 24 (18) 47 (35) 81(60) 194 (143) 385 (285) 665 (490) 1310
(966.2)
10.9 4.0 (2.9) 8.1 (6) 14 (10) 33 (24) 65 (48) 114 (84) 277 (204) 541 (399) 935 (689) 1840
(1357)
12.9 4.9 (3.6) 9.7 (7.2) 17 (13) 40 (30) 79 (58) 136 (100) 333 (245) 649 (480) 1120
(825.1)
2210
(1630)
Hexagon screws with countersunk heads
For hexagon socket head screws with countersunk head, maximum torque for all property
classes must be 80% of the values for property class 8.8 above.
8 Maintenance
Concertor ™ 6020 Installation, Operation, and Maintenance Manual 35