Goulds Pumps NM3171 - IOM - Manual (Page 26)

26. Spray shaft (122) threads and impeller (101)
threads with Loctite Locquic Primer T or
equivalent. Allow 5 minutes for drying.
27. Coat entire threaded area of shaft (122) threads
with Loctite 242 or equivalent.
28. Evenly disperse three (3) drops of Loctite 242 or
equivalent on impeller (101) threads. Refer to
manufacturers literature for set and cure times.
29. Screw impeller (101) on shaft (122) assuring
impeller does not touch pump cover (180). If
impeller does hit, use adjusting screws (370D
and 370C) to correct. Firmly tighten impeller
using Shaft Key Wrench.
Model NM 3171 impellers are threaded onto the
pump shafts. Removal can be difficult unless some
means is used to hold the shaft from turning.
Figure 1 shows a "shaft key wrench" which is an
excellent tool for holding the shaft. It provides a
positive restraint and does not damage the shaft or
coupling hub as a pipe wrench could.
The impeller should be turned clockwise by hand,
raising the shaft key wrench off the table or floor.
The impeller should then be given a quick turn
counter-clockwise causing the wrench to impact the
table.
The shaft key wrench has Goulds Part Number
A01676, and customers can order through their local
Goulds Pumps sales office.
NOTE: NEVER USE HEAT TO ASSIST IN
IMPELLER REMOVAL! The application of
heat to the hub or nose area of the impeller
will not aid in removal and could cause the
hub area to fail.
30. Align casing studs (356A) with pump cover (180)
and fasten with nuts (425). Torque nuts (425) to
values shown in table C-l.
31. Check axial travel of the impeller (101) within the
casing (100) by using the procedure in Impeller
Adjustment (page 20).
32. Replace casing/discharge pipe assembly gasket
(351A).
33. Connect discharge pipe assembly (195) to
casing using screws (371H).
34. Tighten pipe collar set screws (222J). Make sure
no strain has been placed on the pump. Rotate
shaft (122) by hand to assure that no bending is
present.
35. Replace casing/suction tail pipe assembly
gasket (360Y).
36. Align suction tail pipe assembly (161) with
casing (100) and fasten using screws (372A).
37. Reconnect flush tubing (190) to bearing housing
assembly (213).
38. Install motor support (240) on adapter (106)
using screws (371S).
39. Install coupling hub.
Refer to the Installation section for instruction on
installation. Particular attention should be directed
to instructions concerning alignment and rotation.
IMPELLER ADJUSTMENT
Model NM 3171 is designed so that the impeller
must be adjusted relative to the casing.
This procedure should be followed with pump
installed in the vertical position.
1. Disconnect coupling.
2. Loosen bolts (370D) evenly while slowly rotating
the shaft (122) clockwise until impeller contacts
pump casing (100).
3. Place and zero a dial indicator on top of shaft
(122).
4. Tighten evenly and alternately impeller
adjustment bolts (370D) until dial indicator reads
.015" (.38mm). This adjustment has raised the
impeller from contact with the casing (100) .015"
(.38mm) which is the normal clearance between
these two parts.
5. Tighten bearing end cover/bearing housing
screws (370C). Rotate shaft (122) to ensure no
binding or rubbing of parts occurs.
6. Install coupling guard.
20
NM 3171 IOM 5/08
Fig. 1