Xylem Flygt 3201, Installation Operation & Maintenance, Page: 34 / 48

Maintenance
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.
Torque values
Screw and nuts
Stainless steel, A2 and A4
Property
class
M4 M5 M6 M8 M10 M12 M16 M20 M24 M30
Torque,
Nm (ft-
lbs)
70 +80 2.7 (2) 5.4 (4) 9.3 (6.9) 22 (16) 44 (32) 76 (56) 187 (138) 364 (268) 629 (464) 1240
(915)
Carbon steel and alloyed steel
Torque,
Nm (ft-
lbs)
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)
10.9
4.0 (2.9) 8.1 (6) 14 (10.3) 33 (24.3) 65 (48) 114 (84) 277 (204) 541 (399) 935 (689) 1840
(1357)
12.9
4.9 (3.6) 9.7 (7.2) 17 (12.5) 40 (30) 79 (58) 136 (100) 333 (245) 649 (480) 1120
(825)
2210
(1630)
Screws with countersunk heads
Stainless steel, A2 and A4
Property
class
M4 M5 M6 M8 M10 M12 M16 M20 M24
1
Property class 70 is torque tightened as class 80.
Maintenance
32 Flygt 3201 Installation, Operation, and Maintenance Manual