10.2.1 Installation types S and C, all ranges
Adjust the clearance between the impeller and the pump housing
by following these steps:
1. Slacken the set screws by two full turns each.
2. Close the impeller clearance by lightly tightening the fastening
screws diagonally until the impeller touches the pump
housing.
Warning
Do not use too much force when tightening the
fastening screws as this may damage the
bearings. The movement is usual 0.039 to
0.118 inch (1 to 3 mm).
3. Slacken the fastening screws to make an 0.027 inches
(0.7 mm) gap under the head of the fastening screws.
See fig. 18.
4. Tighten the set screws tightly.
5. Tighten the fastening screws diagonally.
Set screw
Fastening screw
Fig. 18 Impeller clearance adjustment
10.2.2 Installation types D and H, range 50-54
Adjust the clearance between the impeller and the pump housing
by following these steps:
1. Slacken the set screws by two full turns each.
2. Close the impeller clearance by lightly tightening the fastening
screws diagonally until the impeller touches the pump
housing.
Warning
Do not use too much force when tightening the
fastening screws as this may damage the
bearings. The movement is usual 0.039 to 0.118
inch (1 to 3 mm).
3. Slacken the fastening screws to make an 0.027 inches
(0.7 mm) gap under the head of the fastening screws.
See fig. 18.
4. Tighten the set screws tightly
5. Tighten the fastening screws diagonally.
Fastening screw
10.2.3 Installation types D and H, range 58-70
Adjust the clearance between the impeller and the pump housing
by following these steps:
1. Slacken the six fastening screws and close the impeller
clearance by tightening the three set screws. Tighten the
screws diagonally to move the suction cover evenly.
Warning
Do not use too much force when tightening the
fastening screws as this may damage the
bearings. The movement is usual 0.039 to
0.118 inch (1 to 3 mm).
2. Measure the distance "L" between suction cover and pump
housing at three points next to the set screws, using feeler
gauges or callipers, and make a note of the distance.
3. Slacken the set screws and draw back the suction cover by
between 0.020 and 0.035 inches (0.5 and 0.9 mm). using the
six fastening screws (approx. one 270 ° turn of an M12
fastening screw) and the distance "L" as reference.
See fig. 19.
Tighten all set screws and check that the distance "L" at the three
reference points is stable at the new value.
Set screw
Fastening screw
Fig. 19 Impeller clearance adjustment
10.3 Contaminated pumps
Warning
If a pump has been used for a liquid which is
injurious to health or toxic, the pump will be
classified as contaminated.
If Grundfos is requested to service the pump, Grundfos must be
contacted with details about the pumped liquid, etc. before the
pump is returned for service. Otherwise Grundfos can refuse to
accept the pump for service.
Possible costs of returning the pump are to be paid by the
customer.
However, any application for service (no matter to whom it may
be made) must include details about the pumped liquid if the
pump has been used for liquids which are injurious to health or
toxic.
Fastening screw
21