Goulds Pumps VIT - IOM - Manual (Page 50)

Adjust the impeller for a hollow-shaft driver
NOTICE:
• If your hollow-shaft driver has a mechanical seal, you must disengage it prior to impeller adjustment.
• Improper impeller adjustment could cause contact between the rotating and stationary parts, resulting
in sparks and heat generation.
This procedure applies to the open and enclosed impeller:
1. Make sure that the shafting is all the way down and that the impellers are resting on their seats.
2. Turn the adjusting nut in a counterclockwise direction to lift the shaft until the impellers just clear
their seats and the shaft turns freely by hand.
This removes all deflection from the shaft.
3. Align hole A in the adjusting nut and hole C in the motor coupling.
If you are careful, you can reach an initial impeller clearance between 0.001 in. to 0.003 in. (0.02 mm
to 0.07 mm) depending on the shaft size and thread data shown in this table:
Shaft size Thread Vertical movement in 1/20th
turns - adjusting nut
¾ in. (19 mm) ¾-16 LH 0.003 in. (0.076 mm)
1 in. (25 mm) 1-12 LH 0.004 in. (0.10 mm)
1 3 /
16
in. (30 mm) 1-12 LH 0.005 in. (0.12 mm)
1½ in. (38 mm) 1-10 LH 0.005 in. (0.12 mm)
1 11 /
16
in. (42 mm) 1-10 LH 0.005 in. (0.12 mm)
1 15 /
16
in. (49 mm) 1-10 LH 0.005 in. (0.12 mm)
2 3 /
16
in. (55 mm) 1-10 LH 0.005 in. (0.12 mm)
2 7 /
16
in. (62 mm) 1-10 LH 0.005 in. (0.12 mm)
2 11 /
16
in. (68 mm) 1-8 LH 0.006 in. (0.15 mm)
AA
A
B E
F
1
2
C
D
H
G
BB
3
1. Lower impeller
2. Raise impeller
3. Correct impeller rotation
Installation (Continued)
48 Model VIT Installation, Operation, and Maintenance