Goulds Pumps 3500XD - IOM - Manual (Page 39)

3500XD IOM 8/07
35
INSPECTION AND OVERHAUL
Impeller and Repeller
Replace if impeller, X-Ducer nut, or repeller show excessive
erosion, corrosion, extreme wear or vane breakage. O-ring
grooves must be in good condition. Check condition of
bores, as fit on shaft is critical (0.0010 to 0.0025” clearance
standard). Check impeller balance if possible (max.
unbalance of 3.6 in-oz. standard).
Inducer and Centrifuge
Replace if they show excessive erosion, corrosion, or
bent/broken vanes. Check condition of o-ring grooves.
Suction Sideplate
Replace if sideplate shows excessive metal loss due to
corrosion, erosion or wear.
Shaft
Check for runout to see that the shaft is not bent. Bearing
seats and labyrinth seal areas must be in perfect condition and
free of scratches and grooves. O.D. and finish in these areas
must be within bearing manufacturer’s specifications. Check
that the keyway is free of corrosion. Replace shaft if
necessary.
Shaft Sleeve
The shaft sleeve is a push fit and is bored 0.001” to 0.003”
larger than the shaft and should tap easily on the shaft. If the
sleeve does not tap on easily, the bore and shaft should be
inspected to see that they are free from foreign matter or
burrs. The fit of the key in the keyway should also be
checked to see that it is not causing binding. The key should
have a sliding fit on the sides and should have clearance at
the top. Sleeve surface in stuffing box must be smooth and
free of grooves. If grooved, replace. O-ring groove must be
in good condition. The original diametrical clearance
between shaft sleeve and stuffing box bore is 0.025” to
0.032”. If this clearance has increased to more than 0.050”,
the shaft sleeve, and at times the stuffing box, should be
replaced.
Mechanical Seal
Lapped seal faces, gaskets, and shaft sealing members must
be in perfect condition or excessive leakage may result.
Replace worn or damaged parts.
Ball Bearings
Replace if worn, loose, rough or noisy when rotated.
Replacement bearings must be of the proper size and type as
specified in the construction details (Table 6).
Labyrinth Oil Seals
Inspect and replace if o-rings are torn or otherwise damaged.
General
All parts should be clean before assembly. This is especially
important at O-ring grooves, threads, lock fits, gasket
surfaces and bearing areas. Any burrs should be removed
with crocus cloth. Replace all gaskets and o-rings when
maintenance is performed.
6
Table 6
BEARING DESIGNATION VS PUMP SIZE AND GROUP
Pump Size Group Thrust Bearing Radial Bearing
3x6-14XD S SKF BA2B459313 SKF NUP-313ECP
4x8-18HXD M SKF 8317 SKF NUP-317ECP
6x10-18 M SKF 8317 SKF NUP-317ECP
6x10-22HXD M SKF 8317 SKF NUP-317ECP
4x8-24 XD L SKF BA24B459422 SKF NUP-222ECP
6x12-24XD L SKF BA24B459422 SKF NUP-222ECP