Goulds Pumps AF (Axial Flow) (42"/1200mm/54/60"/66") LM/LMR Bearings - IOM" - Manual (Page 18)

18 AF (42-66) IOM
when the system is cold. The jam nut keeps the stop
nut from turning during normal operation when the sub-
base has been pushed down from the thermal
expansion. The adjusting screw holder is a bearing
surface for the end of the adjusting screw and serves
to hold the end of the screw in a fixed location.
The adjusting screw was lubricated at the factory but
should be re-lubricated with heavy protective grease
during the pump installation. The springs and other
parts should be coated with an agent to protect the
surface from corrosion, and a heavy lubricant should
be applied to the adjusting screw holder pocket.
The following steps are used to set the springs and
level the sub-base:
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" or 1.6 mm) should exist
between the flange of the vertical pipe and the pump
elbow with the gasket in place (Fig. 10).
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” (0.8 mm) 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” (0.8 mm), turn
the adjusting screws a uniform amount to close the
gap. For a gap of 1/32” (0.8 mm) 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.
Fig. 10
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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