Goulds Pumps AF (Axial Flow) (6"-36) MXR Bearings" - Manual (Page 20)

18 AF (6-36) IOM
1. Place blocks under the sub-base, near each spring
holder, and position the sub-base level on the
blocks. A small gap (approx. 1/16”) should exist
between the flange of the vertical pipe and the pump
elbow with the gasket in place (Fig. 12).
2. Install several flange bolts to help maintain
alignment of the flanges.
WARNING
Do not tighten bolts.
3. Position the adjusting screw holders, while the
adjusting screw end is seated in the hole, in the
direction of the horizontal thermal expansion. This
will allow the required horizontal motion without
having the adjusting screw nut assembly hit the
walls of the spring holder. Make sure there is
sufficient clearance between the adjusting screw
holder and the bottom of the sub-base for vertical
thermal expansion. This clearance is usually shown
on the pump installation drawing.
NOTE: Each spring carries a share of the unit load
but generally do not carry equal loads. Each holder
has a small "window” to check the spring coil
spacing, which is an indication of the relative load
on the spring. The installation drawing may indicate
the approximate number of turns required for each
spring location, especially if the unit uses more than
(4) springs. If necessary refer to table 1 for spring
rate information.
4. Turn the adjusting screws until the bottom of the
sub-base just clears each block. Next adjust each
screw evenly until the pump flange and gasket are
less than 1/32” away from the pipe flange. Careful
adjustment is necessary to keep the pump level and
obtain better weight distribution on the springs. After
the springs have been loaded and adjusted, the
base should be off the support blocks and level.
5. Check the alignment of the impeller and the pump
elbow. If necessary, correct the alignment by
adjusting the springs or by using shims.
NOTE: If the flange gap is over 1/32”, turn the
adjusting screws a uniform amount to close the gap.
For a gap of 1/32” or less, omit this step.
6. Tighten the vertical pipe flange bolts, recheck the
alignment and connect the horizontal pipe flange to
the elbow. The pump unit should be level and there
should not be any rubbing of the impeller in the
elbow when the shaft is turned by hand.
7. Run each stop nut down to make light contact with
the spring retainer. Lock in place by turning the jam
nut down tight against the stop nut.
8. Inspect each spring holder to check the gap
between the coils of the spring. There must be
enough total gap to accommodate the downward
thermal expansion of the system without having
them compressed solid.
NOTE: Pumps with oil lubrication should be checked
for being level while thermal expansion is taking
place. It may be necessary to add oil to the bearing
housing to provide the proper oil level to the higher
bearing. A line parallel with the sub-base deck
through the proper oil level line will show the correct
level at the highest end of the bearing housing. A
horizontal line back from that point will establish the
proper level mark on the sight gauge.
The system should be operated at normal temperature
before the adjusting screw holders are grouted in place.
Some customers operate their units with the adjusting
Fig. 12
1/16”
FLANGE
BOLTS
BLOCKS
Spring Size Wire Size Spring Rate Adjusting Screw Size Load Change per Full Turn
1 .812” 1140 #/in. 1-1/2”-6 UNC 190 #
2 .750” 760 #/in. 1-1/2”-6 UNC 127 #
3 .532” 560 #/in. 1-1/2”-6 UNC 93 #
4 1.00” 1000 #/in. 2”-4-1/2 UNC 222 #
5 .375” 133 #/in. ¾”-10 UNC 13 #
Table 1
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