Grundfos NB Original Installation And Operating Instructions page 7

5. Press down the threaded pipe to ensure that the shaft is in
bottom position.
7. Apply Loctite 243 to the threads of the hexagon socket
screws. Tighten the screws to the correct torque.
See below.
M5: 6 ± 2 Nm
M6: 8 ± 2 Nm
M8: 15 ± 3 Nm
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6. Remove the threaded pipe.
8. Fit the coupling guard. Tighten the screws to the correct
torque. See below.
M5 x 10 mm: 6 ± 2 Nm